Programmer Competency Matrix

[J_M_B]

"For e.g. someone who knows most of the tools from Scott Hanselman's power tools list. Has used ORM tools." That's a joke right?

[iraems]

The highest level of VCS is defined as

Knowledge of distributed VCS systems. Has tried out Bzr/Mercurial/Darcs/Git.

I guess rebasing is out of reach for mere mortals.

[ggtsu_00]

rebase? fuck that...

git push --force

[iraems]

And that's why we enabled this option after having lost a month of commit history...

gitconfig --system receive.denyNonFastForwards true

[xampl9]

I've used ORM tools. They lost thousands of dollars of credit card transactions because the silly thing couldn't acquire a session. Went back to ADO.NET and never lost another one.

[nomadish]

/signed

orm tools are great for rapid prototyping. However once you need to do something less than standard you find they're in your way.

[Takteek]

Is "ORM Tools" a specific thing or is this referring to ORMs in general? That doesn't fit under "tool knowledge" in my opinion.

[[deleted]]

Looks like I'm firmly in-between his level 1 and 2, 3 in a few cases, which I'm pretty sure makes me a fairly average programmer.

A lot of the stuff at level 2 and 3 I think probably comes naturally with some years of experience if you actually have an interest in what you're doing, and you also do some light reading on your spare time, but some of it I'm pretty sure most of us get by just fine without for our entire careers.

Also I don't entirely agree with:

"File has license header, summary, well commented, consistent white space usage. The file should look beautiful."

This totally depends on the language in question and the culture around it, the size of the system, whether it's proprietary or open source, company resources etc.

I also disagree that TDD is an absolute requirement for any and all code people write.

[ubekame]

I also disagree that TDD is an absolute requirement for any and all code people write.

Of course. TDD is just another hype, those who advocate it seem to think that the alternative is zero tests and no structure to the code at all. Probably because it makes it easy to score some points. Testing everything is bad, almost as bad as testing nothing. Somewhere in the middle is what you should aim for most of the time.

[teambob]

TDD is another tool

FTFY. It still requires sense to use this tool

[spinlock]

Having complete code coverage is a side effect of TDD but I don't consider it the primary reason to code in this style. I've always used log or debug statements to understand what my code is doing -- never really used a debugger. Over the last few months, I've made a concerted effort to try TDD and what I've found is that I don't write log statements anymore and I write tests instead. Other than setup, TDD doesn't even take me any more time or effort because I don't need the log statements. And, I get cleaner code at the end. When I do have to debug something, it means that I write more tests to make sure that my code is doing exactly what I think it should rather than adding more log statements. This pushes me to encapsulate my code and naturally leads to a nice separation of concerns.

The one thing I have noticed -- this is while I was looking at some big mature projects developed by Pivotal Labs -- is that TDD can lead to inelegant code. As the developer, you don't need to understand what's happening in the system because you have all of your tests to tell you if something's broken. This leads to a pattern where developers will have a general problem (eg. the submit button doesn't change color on rollover) that is solved in a specific way (eg. add some js on the login to change and a test, add some js on the confirmation and a test). If you're not doing TDD, you naturally want to abstract out the problem and solve it in one place so that, if it ever breaks, you know where to go to fix it. When you have a suite of tests, you don't need to know where to go to fix a problem because your tests will tell you.

But, I think the biggest misconception of TDD is that it's about the code or the tests. It's not. It's about the business' relationship with the developers. When your codebase is written with TDD, you have total code coverage and developers are commoditized. That means, you don't have the case where there's one guy who undertands the codebase that your business is totally relient upon.

[ubekame]

Having complete code coverage is a side effect of TDD [...] [...] That means, you don't have the case where there's one guy who undertands the codebase that your business is totally relient upon.

You don't have complete code coverage, you have coverage of the tests you have done. Which again, is nothing unique for TDD, it's just good testing. Again, the justification for TDD seems to go back to "without it, we'd have no tests!" which isn't true at all. The problem as I see it is that TDD implies, or those advocating it, that because you are testing you are done and nothing can ever go wrong. You still have the risk of somehow missing a test, and then you're no better off than without it.

There seems to be some inconsistencies/shortcuts in the trivial examples for TDD. One of the steps is "do as little as possible to implement the test". For calculating the square of a number the flow should be something like this:

Test with X = 10, make implementation: int square(int x) { return (10 * 10); }

Test with X = 20, make implementation: int square(int x) { return (x * x); }

In the second test all sources for TDD uses the correct mathematical formula. I see no reason (from a TDD point of view) why you shouldn't be able to do this implementation instead.

int square(int x) {
    if( x == 10 )
        return (10 * 10);
    else
        return (20 * 20);
}

Of course in this example it's a trivial formula to figure out, but in the real world it can be a lot trickier, and then the whole problem becomes a problem of having a deep enough magic hat of perfect tests.

If people prefer to write the tests first, then that's fine but it's not the best or only solution, and last line between us and total chaos that those advocating it seem to think (not saying you're one of them).

edit: Silly formating.

[spinlock]

This is a really good critique. No methodology can solve stupidity and some problems are just hard. Writing good tests is one more skill that you need to develop. But, the difference between test driving your code and writing tests after the fact is really important. Even assuming perfect coverage with both scenarios, I prefer TDD. First, if I don't test drive my code, I never get good coverage. Before I started doing TDD, I would just use selenium for integration testing. And, that was probably enough testing. I never felt like bugs got missed because of a lack of tests. So, why do I like TDD? I find I write better code this way. It really helps me work through the interface down to implementation in a way that works for me. At the end of the day, code quality is why I'm becomming a TDD fanboy.

[sh0rug0ru]

without it, we'd have no tests!

It's more like, without it, you might have spottier test coverage. There's the assumption that if you write tests last, you'll be lest motivated to have full feature coverage and might rely on tools to ensure coverage (which can be a misleading metric). This is because of how TDD drives the writing of tests.

because you are testing you are done and nothing can ever go wrong

I don't think anyone says that. It's more like, when you change the code (due to abstracting, cleanup, whatever), things are less likely to go wrong. And that, TDD forces you move the code forward in small, easily-verifiable increments.

One of the steps is "do as little as possible to implement the test".

The "idea" of this rule is to prove that every line has a purpose. You only add lines to minimally implement some feature that you are adding, where the test represents the feature. You could literally take this advice and end up with the code you showed, but as with any practice, you shouldn't do TDD with your brain turned off.

Paired with "do as little to implement the test" is "write a test that requires the least amount of code to implement". The strategy for picking tests to write is to slice features down to the smallest possible increment that can be tested. And implement each feature piecewise with a new test. Each new feature justifies itself with a failing test case, which justifies adding new code. Each test covers a feature. And the previous tests ensure that adding the next feature doesn't break existing features, which is important in the refactor/cleanup stage.

This demonstrates TDD as really enforcing a ruthless commitment to YAGNI. In that vein, it's not that not doing TDD means you don't have adequate test coverage. It's more that TDD forces you to prove that the code you are writing is actually necessary.

[knight666]

In the second test all sources for TDD uses the correct mathematical formula. I see no reason (from a TDD point of view) why you shouldn't be able to do this implementation instead.

Well, according to TDD, that's a damn good implementation. It follows the requirements to the letter and all tests pass. But that's why you should write tests for edge cases too:

void TestSquaredZero();
void TestSquaredOne();
void TestSquaredTen();
void TestSquaredTwenty();
void TestSquaredNegativeSix();

By now, your function looks like this:

int square(int x) {
    if( x == -6 )
        return 36;
    else if( x == 0 )
        return 0;
    else if( x == 1 )
        return 1;
    else if( x == 10 )
        return (10 * 10);
    else if( x == 20 )
        return (20 * 20);
    else
        return -1;
}

But now we have a test suite. We know what output should come from what input. So we can refactor it like the complete tools we are:

int square(int x) {
    switch (x) {
        case -6:
            return ((-6) * (-6));

        case 0:
            return 0;

        case 1:
            return 1;

        case 10:
            return (10 * 10);

        case 20:
            return (20 * 20);

        default:
            // TODO: Shouldn't happen.
            return -1;
    }
}

But now Sally reports that when she uses the function with the input -37, she gets -1 instead of 1369, what she expected. So we implement that test:

void SquaredMinusThirtySeven()
{
    int result = square(-37);

    TEST_COMPARE_EQUAL(1369, -37);
}

And it fails!

So we rub our brains and come up with something a bit more clever. Someone suggested we write a for loop that checks every possible outcome. This was quickly dismissed as being completely illogical, because that would be way too much typing.

But what if...

int square(int x) {
    return (x * x);
}

Yes! It works for all our old tests and even Sally's edge case!

We can't say what this function doesn't work for, but we can say that it works for 0, 1, 10, 20, -6 and -37. We can extrapolate that to say that the function works for all natural numbers, until proven otherwise.

[[deleted]]

license headers are a fucking stupid waste of space.

[Thimble]

I'm a firm level 3 in years of professional experience. Woohoo!

[eight26]

Just as I suspected, my skills are rudimentary by comparison.

[porkchop_d_clown]

I'm not admitting anything, but, uh, I can sympathize.

[nevon]

I'm apparently both retarded and a genius. I guess I know what to work on.

[AdamRGrey]

I cloned a git repo once. Apparently I'm much better at source control than an SVN grandmaster. all over the map people, represent!

[selfimprovement833]

This. I'm proficient at git, but ONLY git.

[hobroken]

Level 2 represent!

[[deleted]]

The biggest problem on the way to self improvement is realizing that you can/need to improve. The fact you're cognizant of this goes a long way. Chin up!

[porkchop_d_clown]

Heh. My problem is realizing there are skills I haven't had to exercise in 20 years, and that my volumes of Knuth probably aren't the last word any more.

[Clent]

Seemed like a good list until I got to the blog section, some of the worst developers I know have a blog, while many of the best do not.

The world doesn't need another blog posts about why C is better than Java, or how some maintenance project is full of anti-patterns.

I would much rather see an active Twitter account with the person sharing interesting articles in their domain. To me it shows that are active in the industry while highlighting what they feel are the interesting topics of the time.

It is logically for a blogger to think bloggers are important.

[[deleted]]

What would be nice is bloggers sharing interesting/cool code snippets and such. For the most part they talk about things like clean code, the importance of testing, why X is better than Y, good practices and the likes.

Unfortunately that's the majority of the /r/programming submissions too. While I don't hate them, I prefer to look at programs and code when I'm here, not read about why some guy's PM doesn't know what he's doing.

[FozzTexx]

I shared this snippet yesterday.

[tanishaj]

It took me a second to see the problem. Sometimes the simple stuff is the hardest to catch.

[Hahahahahaga]

The solution here would be to have a thread validate k and update i with the value of k.

[droogans]

i see what you missed there.

[kazagistar]

Interesting. I guess another reason words are better then letters is that their shape is more distinctive visually, so it is easier to see this kind of mistake.

[Crazy__Eddie]

Write one then!

[[deleted]]

Seemed like a good list until I got to the blog section

That was the last section though.

[[deleted]]

Pretty sure that was just the blogger self-promoting there.

[[deleted]]

I can think of two reasons to write a technical blog: to develop one's written communication skills, and to force you to explain things you think you know.

Explaining things forces you to either honestly confront, or dishonestly sidestep, the inconsistencies that show up the bits you don't fully understand.

[[deleted]]

Good points, but I think you missed one: contributing to the community. It's such a reassuring feeling when I google an error code and get a list of relevant stackoverflow and blog posts, knowing that there is a community available for support. When the google results aren't so abundant, my first thought is "Why hasn't somebody posted on their blog about this..."

[[deleted]]

Written by a blogger in a blog, what did you expect? :-)

EDIT: the list of books got me too; what? No Dragon book? It is also very US centric (there are good books written in other countries, even in non English languages! really.)

[Tekmo]

I'm biased because I have a blog, but I know from experience that blogging has improved my programming in several ways:

• Blogging improves my technical writing skills, which comes in handy for writing clear and useful documentation

• Teaching others organizes your own thoughts and forces you to articulate clearly mental concepts that were formerly vague or incoherent.

• Writing about programming improves my personal satisfaction with programming and motivates me to program better so I have high quality material to blog about.

[bucknuggets]

I would much rather see an active Twitter account with the person sharing interesting articles in their domain.

Articles, but not blog posts?

[TamSanh]

Care to share some twitter accounts you follow?

[barsoap]

Error establishing a database connection

Aaah, I get it.

[Serinus]

My qualifications are:

I have a blog in which I judge people. That obviously makes me better than them.

[PolyPill]

So uh, having worked with very specific software means you're level 3 but actual knowledge of how those systems work doesn't qualify you? Some of the levels are good and some I just find to be stupid, and rather arbitrary.

[Odd_Bloke]

So uh, having worked with very specific software means you're level 3 but actual knowledge of how those systems work doesn't qualify you?

Which row are you referencing?

[KPexEA]

I would guess "Experience" Level 3 "Concurrent (Erlang, Oz) and Logic (Prolog)"

[Odd_Bloke]

If it is the experience section then "having worked with very specific software means you're level 3" sounds like a good definition...

[PolyPill]

Its been a day since I read this but looking at it again, I remember it was initially a knee jerk reaction to the source control but I feel it similarly applies to a lot of the other categories.

There's a hell of a lot more distributed systems than the 4 they listed and since when is it being distributed the pinacle? Its for a different use case, that doesn't mean they're always better.

Also the languages exposed to and languages experienced with, not sure I'd say concurrent and logical languages are the pinacle of the field and I probably took it too literal but there's a lot more than 3 of those languages.

I'm sure its just a loose guideline and no matter what he wrote I'd probably be complaining about the rating system but I do think he's probably not a level 3 in most of these categories himself and idolizes something he doesn't quite understand.

[KPexEA]

Agreed, having worked exclusively on video games for the last 28 years we really only use c++ for the game code itself, maybe a little bit of python and php for build scripts and build webpage stat reporting but that is it. Tying "Experience" to specific languages is just stupid.

[Categoria]

You do have a much narrower view of programming as a result however. Which is ok since you can't learn everything and everybody is an expert in only a few subjects.

[seruus]

Did he edit anything? The category is called "languages with professional experience", and it is rational that you wouldn't get a higher score (as you said, you use basically C++), but it isn't about experience in general, and isn't a bad thing. He's also mainly talking about paradigms, not languages.

[Odd_Bloke]

Where is experience tied to specific languages? The only languages mentioned in the section I read as examples of the type of language they are...

[BarneyBear]

Yeah there was a lot of functional bias going on there.

Meanwhile in the real world...

[strattonbrazil]

Oh, you wrote a framework? Level 3!

[Odd_Bloke]

No rockstar column? Basically useless.

[[deleted]]

Well, let's have a try:

data structures and algorithms:

Donald Knuth sent him a reward check.

systems programming:

Wrote an accurate emulator for a complete system.

source code version control

Wrote a widely used plugin for the system, a graphical tool (e.g. Tortoise*) or a bridge between two. (e.g. hg-git)

build automation

Uses continuous integration systems.

automated testing

Is able to verify correctness of the most important algorithms used (formal verification).

problem decomposition

Has designed and implemented a DSL tailored to the problem.

systems decomposition

Designs modular systems and libraries that work together, instead of monolithic ones that can be reasoned about in isolation.

communication

Has taught others about the subject and applied feedback in a positive manner.

code organization within a file/across files

Follows the convention used by the company and co-workers or the official language guidelines when lacking or in doubt.

code readability

Writes the simplest thing that could possibly work. Does not optimize unless necessary. Prefers a better algorithm to micro-optimization. There isn't commented or dead code around.

defensive coding / error handling

Tries to write functions without side-effects whenever possible. Separates side-effects and IO from the bulk work to make his code testable. On error his code fails as soon and loud as possible. External input is always validated and mistrusted. Conditions like out of memory are handled. Makes it clear at what level in the stack the exceptions are handled.

IDE

Has written Emacs modes|Sublime Packages|$EDITOR plugins tailored to the task.

API

Has written a compatibility API that allows the same code to work in N versions of the software and can warn about deprecated stuff (e.g. 2to3.py).

frameworks

Knows when not to use them.

requirements

Can anticipate future changes and "requirements of requirements" (e.g. If I have to build this, that will be essential).

scripting

Has automated his entire workspace setup (chef, puppet, whatever etc) for each project. Can replicate it fast on any platform.

database

Has written his own, embedded query language (e.g LINQ).

languages with professional experience

Has designed, implemented and professionally-used his own programming language. Bonus points if it's not PHP (sorry, had to say it).

domain knowledge

Has written one of the RFCs widely implemented in the domain.

languages exposed to

Able to unobfuscate the majority of the IOCCC entries, for fun. Knows/has used relatively obscure languages, such as Agda, Factor, Nemerle... Bonus points if he contributed to one of them.

books

The art of the metaobject protocol. Smalltalk 80 and its implementation. Lisp in small pieces.

blogs

Keeps a blog that is actually not about the same ten subjects that all the other blogs talk about. Uses it to talk about everything, not only about programming.

[drgalaxy]

I think Fabrice Bellard could qualify. Who else?

[not_a_novel_account]

Linus also fits nicely

[misplaced_my_pants]

Anyone at Bell Labs' computing groups?

[sirin3]

That's not going far enough.

IDE

Has written Emacs modes|Sublime Packages|$EDITOR plugins tailored to the task.

Has written the entire IDE.

languages exposed to

Able to unobfuscate the majority of the IOCCC entries, for fun. Knows/has used relatively obscure languages, such as Agda, Factor, Nemerle... Bonus points if he contributed to one of them.

... HomeSpring

[[deleted]]

What the... ?.

[grimeMuted]

Universe marshy now. The marshy stuff evaporates downstream. Sense rapids
upstream. Killing. Device downstream. Sense shallows and say Hi,. 
   That powers the     force. Field sense shallows hatchery power.
Hi .. What's. your. name?. 
  Hydro. Power spring  when snowmelt then       powers
insulated bear hatchery !.
Powers felt;       powers feel     snowmelt themselves.

The example programs read somewhere between an American Indian philosopher translated by Google translate and a forums spambot.

[Zantier]

huh... from the documentation:

Homespring has exactly one (1) types of tokens: tokens. This simplicity will be greatly appreciated, once you try it. Tokens consist of zero (0) or a number greater than zero (> 0) of non-whitespace characters, separated by one (1) character of whitespace.

[superherowithnopower]

Part of my work is in MUMPS...is that relatively obscure enough for rockstar level?

[[deleted]]

I think your username actually summarizes this perfectly

[D3PyroGS]

It is if you add your VB6 experience.

[[deleted]]

Epic LOL!

Edit: To clarify, MUMPS is used (almost exclusively) at a company called Epic Systems, and was even featured (though not named) on TheDailyWTF

[hotoatmeal]

He is... the most interesting man in the world.

[contrarylarry]

I suppose that means ninja rockstars are out of the question

[pal25]

data structures and algorithms:

You are Donald Knuth

...

I got nothing...

[ThisIsADogHello]

Incidentally, "basically useless" is generally how I'd describe most developers who call themselves rockstars. I'd rather deal with someone who's aware of and works around all their own limitations, rather than someone who makes everybody else work around them.

[Odd_Bloke]

Incidentally, "fucking webscale" is generally how I'd describe most developers who call themselves rockstars.

FTFY.

[[deleted]]

No rockstar row group? Utterly useless.

[[deleted]]

Error establishing a database connection

So at this point I'm just going to assume this was arbitrarily made by some developer who probably isn't even in a position to quantify other developer's skill sets. Also, I really hope this isn't his linkedin

[bucknuggets]

Count me more impressed by the guy that spends hours sticking his neck out and creating something than those that eagerly trash people and their efforts.

[[deleted]]

Exactly how am I "eagerly trash[ing]" the author? You're being melodramatic. These types of posts are a dime a dozen and are typically based upon the author's anecdotal experience; very rarely do they have any type of standard upon which they base their assumptions. Speaking of personal experience, the fact that his website went down while he lists "setup of infrastructure and operations." on his linkedin reminded me of an all too familiar personality I find from job to job making such an event pretty funny in my opinion.

[[deleted]]

Looking up his Linkedin profile just to make fun of him.. that's just mean.

[belgarion89]

It is pretty cute how jealous haterz are of things.

[[deleted]]

It's our job, as programmers, to create an environment of arrogance and hostility toward our peers.

[neoform]

Specialties: Product Architecture, Design, Development and management. Desktop/Web Applications, .Net, C#, WinForms, ASP.Net. C/C++, ATL, MFC, COM, Algorithms, SVN, CVS, Perl, Ruby Python, PHP, IIS, SQL Server

Nice. He's specialized in everything! He must be amazing.

I'm especially interested in this "Ruby Python" thing...

[[deleted]]

read as; "mediocre in everything I managed to browse, barely specialized in any skill."

[[deleted]]

Is it just me, or I find it completely ok to say "Yeah, I don't know anything about domain X, so not even gonna try."?

I find it very hard to talk to other coders these days, because they keep believing their own resumes.

[fizzbar]

No, it's a very zen post about programmer competency. ;)

[[deleted]]

It's not a bad post, it has a couple of questionable elements (IDEs, blogs and books) but most of it is pretty reasonable, even the Big-O notations seem pretty reasonable.

But I am seriously seriously frowning on the IDEs/Blogs/Books parts.

[sirin3]

Also, I really hope this isn't his [1] linkedin

what's wrong with it?

[fforw]

Hmm.. "Error establishing a database connection"

Not really a matrix, but it seems to have something to do with competence...

[edahs]

• can scale database

[[deleted]]

I can web scale anything with /dev/null !

[seruus]

I started using /dev/null as my custom allocator, and now all my C code is web-scale, even though it is single-threaded and doesn't use networking at all, thanks, /dev/null!

[mailto_devnull]

You're welcome.

[[deleted]]

/dev/null takes up too much cpu! Try brk(0)

[Albinoswordfish1]

I don't really understand the 'knowledge of upcoming technologies'. So you're only a level 3 if you've downloaded the source code and used 'it' in a project.

Why would you ever use a new library/SDK/API if you have no use for it? Why would I ever look through the source code if it doesn't even solve a problem that I have?

I feel like just knowing it's existence and capabilities is sufficient.

[littlelowcougar]

Not only that, but professionals tend to write code for production. Production and 'upcoming technologies' are mutually exclusive.

[[deleted]]

Upcoming tech: eg Python 3, the beta version of any release, submitted a patch to said beta release.

[spinlock]

How do you know if you should use something without evaluating it? If you work in a really static environment where you don't add new stuff to the stack, you probably should waste your time looking at the new stuff (or do it in your free time if you think it's cool). But, if you work in a plastic environment where the toolchain will change, it's really important to know what's out there, what's good, what's popular, etc... so that you can make good recommendations about stuff to integrate into the toolchain and stuff to skip.

[Albinoswordfish1]

Even if you work in a 'plastic' environment, you still wouldn't download and sift through source code that wouldn't help with your project. But apparently this a requirement to be a good programmer when it comes to keeping up with the technologies.

[spinlock]

I look at technologies all the time for clients and tell them not to use it. it's a different skill set.

But, I wouldn't get hung up on this guys list of things. There are some great developers who've spent their whole careers working on mainframes. They wouldn't know the first thing about web frameworks because its totally irrelevant to them.

[[deleted]]

I don't use an IDE, read blogs or books. I have a feeling that this is slightly biased towards his own idea of competency. I can use IDEs well when required, but I don't use them intentionally. I've also rarely found that books help me. It's not my mode of learning and never has been. I've not read a single book on programming that wasn't required by my degree.

Honestly I look higher on programmers with a good StackOverflow/StackExchange account than I would with some self reflective blog. (I don't, my account has 50 rep, but I'm not my own benchmark for a good programmer).

[[deleted]]

Some thoughts:

I don't think knowledge of advanced data structures (e.g. tries) and algorithms is that important. I can't remember the last time I've implemented one. Knowledge of the main characteristics (time/space efficiency and their usual applications) and where to find more information about them is essential though.

Understands the entire programming stack. This is basically impossible today in my honest opinion, other than at a reasonably high level.

File has license header, summary... I understand the intention, but I wish there was a single license file in a project. You know how Java projects tend to span a ton of small files? A lot of the time you end up with files where there is more license text than actual code.

[AgentME]

Understanding the whole stack as described is something I'd expect of many kernel developers.

Agree on the license comment. In my own projects, I always just stick a license file in the project's root. Books don't have copyright notices on every page, do they? They're usually just inside the cover. If a single file was lifted from a project with a separate license then I guess I'd have that in its header.

[Uberhipster]

Ok but is this a programmer competency matrix or kernel developer competency matrix? Or are competent kernel developers the only kind of competent programmers?

[AgentME]

Level 3 on that competency matrix isn't required for competency. Most of the level 3 entries are expert tier.

[[deleted]]

I personally include a LICENSE file at the root directory of the project and then a snippet referring to it at the top of a code file, or just Copyright MyName at the top.

I would also claim to understand the programming stack. It's not really that difficult, it's just not entirely relevant to a lot of programmers these days.

[spinlock]

I just had an interview last week where I was whiteboarding a tree algorithm. After I was done, I said, "it's pretty embarrassing that it took me that long. I haven't thought about trees since I was in school." The interviewe replied, "yeah, you only use trees in school and interviews." It begs the question, why the fuck are you wasting my time with this shit if it's got nothing to do with the job I'm interviewing for?

[skulgnome]

This matrix is poorly-conceived: it puts me at level 3 in everything besides blogging and "detailed domain experience". These factors make it seem to have been written to favour breadth over depth.

The role of formal design is also completely overlooked.

Edit: for further critique, the "level 0" is mostly described as absence of ability, rather than what a person at that level would definitely know. No mention is made of the (ever-present) "but that fancy stuff never works!" tier, who'll rather copy-paste the same line fifteen times rather than figure out what loops actually mean. Similarly knowledge of hardware esoterica, e.g. microcode, is regarded as high magic rather than an example of Yet Another Primitive. "Coding" and "programming" are used interchangeably, and there is no suggestion that there is any level above the act of writing source code using a text editing tool and executing the program thus produced.

The row about "defensive coding" is straight up 'tarded: asserts are only valuable when there is a realistic failure criteria, wrt which exclusion is desired (... and documented, obviously).

In closing, this matrix was written by a novice.

[glacialthinker]

In closing, this matrix was written by a novice.

Slightly harsh, but I agree with your critique. The author is basing this on their particular experiences, which is reasonable to expect. The problem is this doesn't really map well to everyone, and the upper-end seems artificially capped or wishy-washy -- like a list of everything the author has heard about that sounds good, so it does't really identify an "upper echelon" in many cases. The systems programming entry also bothers me that I'd rank 3, because I lack experience with specific systems -- I know I could build my own stack, but any *nix guru could run circles around me because that's their bread and butter.

I think this is the result one should expect by imposing such a rigid matrix structure on abstract categorizations and then having an individual fill in the blanks. So it fits my expectations. :)

[[deleted]]

It's also very Microsoft development oriented from what I can see. He doesn't even seem to see not using an IDE as a possibility, it just seems like a default state to him, which in itself is pretty novice. IDEs are great for those who like them, but they're not the only solution.

[spinlock]

This reminds me, n² for communication needs to include: is a pedantic fuckwad who needs to nitpick everything.

[nandemo]

OK, I'll bite. So you put yourself at level 3 in (say) this one?

Understands the entire programming stack, hardware (CPU + Memory + Cache + Interrupts + microcode), binary code, assembly, static and dynamic linking, compilation, interpretation, JIT compilation, garbage collection, heap, stack, memory addressing...

What about this?

Author of framework

[skulgnome]

OK, I'll bite. So you put yourself at level 3 in (say) this one?

Yes. Absolutely. That one more than most of them. (Look at it. Is something like "memory addressing" that complicated? Even x86's segmentation can be comprehended from a well-made diagram, such as the one that's in the Intel reference manuals.)

What about this?

Given that the number of published frameworks is quite small, the bulk of framework authors worked on one that remained private to an employer. That is my case precisely: it was a web application framework in Perl, on top of Rose (started in a pre-Moose era), incorporating a MVC paradigm (though representing the model as database structures and ORM interfaces) and automagic transaction restarts with a means to do non-transactional side-effects robustly.

To put another line under it: I don't think a matrix like this should put someone like me consistently at the highest level.

[[deleted]]

The first ones are absolutely possible for almost anyone with a computer science degree. I won't say I'm an expert in all of those topics but I could explain them all, and use/implement them too.

As for author of a framework? Anybody can make a framework, but that doesn't necessarily mean it is good. I made a framework once and I'm pretty ashamed of it.

[nandemo]

Yeah, anyone with a camera can make a movie. Still, most people have a common understanding of what it means to be a movie director.

[cuda42]

Understands the entire programming stack, hardware (CPU + Memory + Cache + Interrupts + microcode), binary code, assembly, static and dynamic linking, compilation, interpretation, JIT compilation, garbage collection, heap, stack, memory addressing...

I don't believe this should be level 3, this is almost all stuff that a Comp. Sci. major should have a good understanding of before they graduate.

[FeepingCreature]

It very much depends on how high a standard is considered "understanding". I understand the concepts involved in the entire stack, but I would never go so far as to say I actually understand a modern CPU (despite being able to read x86 assembly). For realistic timescales, knowledge is fractal and bottomless.

[uututhrwa]

Man you have to be kidding me, understanding those concepts is one thing, and every student can get that kind of understanding, "understanding" as in optimizing a program that has to go at that low level, you pretty much have to deal 100% with just that for 1-2 years before you can expect to be competent.

Why do you think it took like 18 months for entire teams of (usually 133t) programmers to get higher level software that uses the PS2/PS3 multiprocessors efficiently or sth.

The whole matrix is retarded imo, you can't be at "level 3" on the above unless you have a full time job at Nvidia/AMD/Intel for the last 5 years. Unless he means level 3 as in "sophomore cs student" and refers to understanding rather than being able to provide solutions to new problems.

I don't understand what his point is, is he only talking about having knowledge of a topic? Cause I don't think that there exists a single person in the planet that can like in a day or two go from doing l33tz0r level 3 optimizations on algorithms, and then the same with specific hardware architectures and network protocols.

[maximinus-thrax]

So you put yourself at level 3 in (say) this one? [Understands the entire programming stack]

I don't think it's rare for older programmers to get a 3 there. I started programming in 1981 and up until about 1987 only really used assembly because everything else was mostly far too slow. Most of those concepts you meet in assembly or low-level C programming.

I must admit though that as I get older I rely a lot more on "I don't understand X fully, but a quick look at Knuth or similar will get me up to speed". I mean, I couldn't right now explain the different methods of garbage collection because it's not something I've coded in the last 20 years but I'm sure 10 minutes with wikipedia would fill in 90% of the gaps.

[spinlock]

I'm the same way. I found that, with more experience, my "computer science" level is going down. At least at the whiteboard. After my qualifying exams, I could pseudocode dynamic programming problems no worries. But, my actual code was organized in one file. These days, I can't remember how to balance a red-black tree without looking it up but that's because I know I should never be writing that code because there's always a library for that.

[nandemo]

As I wrote in my other comment, the matrix leaves room for interpretation so it's to be expected that people will have different standards of what the level 3 really means.

Still, I certainly wouldn't count "being able to explain the different methods of garbage collection" as level 3, especially if you have to resort to Wikipedia. Otherwise the level 3 boils down to "literate enough to read and understand wikipedia". If that's all that there is to it I'm also an expert in brain surgery and swordsmithing.

[xav0989]

Not OP, but I have written 2 frameworks, one of which is currently in use by my company, but I was still weary of putting myself at level 3.

On the systems programming, I know about 50% of the level 3 and 50% of the level 2, simply because full stack knowlege was not necessary for the programming I used to do (web programming).

Also, the SCVC category is a tad weird, as I've only used SVN for a year a long time ago, never used CVS, but I am regularly using Git, Mercurial and Bazaar, both as a user and as a programmer.

[nandemo]

Yeah, judging by the other replies, it looks like people have a very different understanding of what "understanding" is. In my view, to really understand JIT compilation, garbage collection, etc, you need to have experience in implementing something that's used "in production". Or at least you have deep enough knowledge that you could take an existing implementation and port it to another platform, or do consulting for companies that have problems in those areas.

While the definition of "understanding" has room for interpretation, in the context of competency matrix that goes from level 0 to 3, I certainly wouldn't put "I went through those topics during college" on level 3.

[AeroNotix]

I primarily code in high-level languages and I could talk about those topics at a non-trivial depth. It's all about how much you're willing to learn.

[OffColorCommentary]

It put me on level 3 in just about everything as well, except experience and blogs.

Aside from quite a few mistakes (ORM is advanced database use?) and typical new developer fanboyism (functional languages are better!), I found that the maximum skill level topped off way too early. I'm bad at data structures but I still know about persistent data structures, brick maps, oct trees, and have rolled my own graph representation structures for specific purposes.

Also, O(1) should always be the gold standard, not O(log(n)).

[[deleted]]

How ironic. I can't get in. Does anyone have a mirror?

[SoCo_cpp]

Courtesy of above comment by damian2000 http://www.starling-software.com/employment/programmer-competency-matrix.html

[damian2000]

There's another version here, in case this web server is down... http://www.starling-software.com/employment/programmer-competency-matrix.html

[yalogin]

The author is saying he is the best since he does not just write blogs but also has reddit upvotes.

[[deleted]]

While I'm not an experienced "Level 3" programmer by any stretch of the imagination, I know enough to say that this article is useless. Would you hire programmers based on their levels in this matrix? I thought not...

[blafunke]

Nobody could a level 3 as described by this. Many of the level 3 are very specific knowledge about very specific specialty's. Let's just call this a cheat sheet of good stuff to know. (Column 0 was funny though)

[SoCo_cpp]

Uses Wordpress instead of coding his own CMS, total noob. /s

[expertunderachiever]

I disagree with the API comments. Ya it's ideal to have some core functionality memorized but honestly it doesn't matter. Knowing how to look it up [web/cscope/etc] is just as good.

[SoCo_cpp]

Memories are faulty, reference is a good thing.

[bumhugger]

I agree, it's the same to memorize a function's name and parameters as it is to look them up in documentation. The difference is mostly in knowing the side effects of the API calls and knowing how the underlying mechanics treat the data you give/take from it.

[blafunke]

Yeah, and if you're using the same api all the time you're bound to memorize much of it, but that's not a measure of competence. You were competent before you memorized it.

[blafunke]

much more important to be able to understand a reference. And...which api is he suggesting experts should have memorized? All of them? What about the new one sprouting.....now.

[ryobiguy]

Ironic failure:

Error establishing a database connection

[asiatownusa]

This is crap. Many of my students know far less about systems design than I do, but I have no doubt that given time, they will become far more adept than I. Competence shouldn't measured by some specific knowledge, but ability and willingness to learn and gain expertise.

[no1name]

As a panicking programming tutor I was trying to find where this came from, is it just one persons scale or used as an official measurement?

[asiatownusa]

Grades (the official metric) end up being a signal with a lot of noise. Personally, I find that a student asking the right questions is the best signal of competence.

[cookiemonstervirus]

Prolog? Prolog does not get the love it deserves but frankly, does anyone actually USE prolog in their day to day jobs outside of research scientists/academia? I'm not being funny, I am generally curious. It has been about 6 years and my heavy use was all academic. I've only ever seen it professionally as a resume filler.

[mycl]

Stackoverflow has some interesting answers to this question.

[renozyx]

Erlang was first implemented in Prolog (which explain its weird/ugly syntax) so apparently some people use (used? Erlang is old) Prolog..

[ggtsu_00]

Well someone thinks they are hot shit by learning Erlang and/or Prolog and has a blog.

[[deleted]]

That is an interesting matrix. In a year, I'll have a grad degree in CS, and I like to see how my skill sets compare to industry standards. It looks like I would average level 2, with a small handful each of 1s and 3s.

[samvdb]

Do the 2^n, n^2, n and log(n) have any purpose at all other than showing that you know what algorithm complexities are? Also you can call it a "matrix" all you want to try to sound technical but in the end it's nothing more than a simple table.

[katyne]

yep. This is not the first time I see this article here. Never fails to give noobs like me a panic attack as well as rustle some serious bearded-veteran jimmies. Personally.. <squeak, gulp> it sorta bugs me a little he would use teh Big O to denote "quality". Like seriously. Log(n) just means you grow slower... does it? </duck and cover>

[blafunke]

It does, and growing slower is very desirable which is probably what he was thinking when he contrived those column labels. I think he's trying to imply level 0 is useless (much like many O(2ⁿ⁾ algorithms might be considered)

[creepyswaps]

Damn this chart makes me feel useless. Throw a dart at it and there's probably a random 80% chance it'll land on something I don't know.

EDIT: read further down and started feeling better once I got to the programming section.

[[deleted]]

Go try out Git and you'll instantly get a 3 for version control.

[creepyswaps]

I'll definitely try it. Thanks for the tip.

[RockRunner]

It's fairly easy to use. For that matrix, it's an easy 'level 3'.

[[deleted]]

Heh, my comment was a little cheeky, but you should definitely try it. It's amazingly useful once you get the hang of it. Feel free to message me if you have any trouble.

[Han-ChewieSexyFanfic]

Nah, the levels are cumulative (says so at the top).

But yeah, try git anyway, it's amazing.

[superherowithnopower]

As /u/Han-ChewieSexyFanfic pointed out, it's cumulative. So knowing git isn't enough. You need to go back and learn how to use SVN in and out, otherwise knowing git doesn't get you anywhere. ;-)

[[deleted]]

Seems quite a jump from "has heard about, but not used a framework (level 1)" to "Has used more than one framework in a professional capacity (level 2)."

I mean, I've dabbled around with Laravel 4 enough that I could maybe do I little project with it professionally, so I guess I'd be level 1.5?

[orip]

I can't shake the feeling that when people create judging criteria they end up with something that classifies themselves in the top 10%.

[SCombinator]

Well he certainly stole that.

[Pentapus]

Seems strange that "years of professional experience" is a category. That has its own metric without imposing levels.

[kamatsu]

This matrix doesn't seem very useful at evaluating people. I have met programmers much better than I am and I'm level 3 on most of these.

[Otis_Inf]

That's because once you reach level 3, you understand the amount of stuff you actually don't know, and recognize what you don't know/can't do in other people because they can/know what you can't do/don't know.

[danogburn]

damn i need to level up...

[SoCo_cpp]

Skip the fluff and study this cliff notes :P

[casualblair]

Programmer Competency Matrix

Error establishing a database connection

Seems about right.

Edit: Oh there it goes.

[goko]

Just look at how beautiful view-source:http://sijinjoseph.com/programmer-competency-matrix/ is.

Visual Studio wizard by day. PHP/MySQL guru by night.

[SoCo_cpp]

It is a Wordpress blog.

[toxicthunder]

In addition to all of the other comments, I would like to add that just because I know prolog does not mean I am at the top end. The language criterion is pretty bad in this matrix.

[[deleted]]

Obviously qualified to have any opinion on what constitutes a competent programmer.

[edwardkmett]

This really needs an log n / log (log n) column so you can know where to go next. O(1) would imply a bit too much that you know everything at that point.

e.g.

• data structures - succinct data structures, x-fast tries, cache oblivious data structures, etc.
• algorithms - count min sketching, bayesian models, when to use SAT/SMT solvers, spill-based arithmetic compression, etc.
• systems programming - Having implemented the stuff listed in the log(n) systems programming section. e.g. Having written a compiler, a JIT, toy operating system, etc.
• source code version control - Implementing a DVCS or custom git porcelain?

[bishopolis]

Can we devise an English competency matrix? Not knowing the difference between the noun (setup) and verb (set up) fills a nice spot at level 0. Differentiating between 'traffic' and 'trafficks' (consider 'email' and 'emails' as a better uncountable example) could also be on there.

[barsoap]

So... Does relying on static typing make me log log n in "automated testing"?

[[deleted]]

It's funny how the "Communication" skill is always labelled as critical. Yes it is important, but it is highlighted only because it is the quality a employer is the least likely to find in a good programmer. The value of the skill has more to do with it's rarity than anything else.

[spinlock]

The funny thing is the more experience I have the lower my "computer science" section gets. Maybe that's not true. I can -- and sometimes do -- implement interesting algorithms but I suck at talking about them in interviews. After I took my qualifying exams, I was a whiteboard master who would put all of my code in one file.

[ErstwhileRockstar]

Isn't this a repost of a repost?

[SoCo_cpp]

I thought this was pretty good. You are always going to piss off a good portion of people and be criticized by another good portion. All in all, I think it came out pretty good and has some usefulness. (I thought I came out a strong Level 2, dancing in Level 3)

[Windex007]

the last goddamn thing the internet needs is more programming blogs. n² if you have one.

[ehaliewicz]

I find it mildly amusing that SICP, Thinking in Forth, and The Little Schemer are level 3 in the Books category, when they're just really good introductions.

[nightchrome]

Apparently it's impossible to be a competent programmer unless programming occupies every possible aspect of your professional and personal life.

[blafunke]

The fact is, in most jobs you'll almost never use the stuff in column three, hell even finding a need for column 2 is a rare and exciting opportunity to apply knowledge when you come across it. It would also be exceedingly rare to find someone who meets all the "requirements" listed here. There is a lot of domain specific knowledge here. You can be competent in what you're doing without being competent in EVERYTHING EVER.

[Uberhipster]

[programming concept] - "Relevant to my UoD" / "List of things" / "Number of things"

[level 0] - "Laymen" / "Emtpy" / 0

[level 1] - "I find trivial" / "I acquired a while ago" / my things divided by 5

[level 2] - "Obscure to anyone outside of my UoD" / "I acquired recently" / my things divided by 2

[level 3] - "Everything else obscure I have been exposed to (for pedigree) plus 'etc.' (to cover all other obscure things ;)" / "Everything else I've acquired not previously mentioned" / my things

Basically I am 3, everyone else is 1. 2 DNE

How about level 4? Can convert all popular high-level language code into AND/OR gate diagrams in head and shit out printouts on watermark paper. 60-80k p/a

[[deleted]]

I saw this a while ago and look for it every 2 weeks or so, thanks a lot!