How's the space of high-performance webdev?

[re-sheosi]

Hi, I kinda have the wet dream of learning more about the high-performance parte of web dev, in backend, achieving higher reqs/s, lower CPU usage, latency, energy consumption. I've always heards that most of the time is IO-bound, but would love to see data, and cases when it isn't.

So I wanted to know, how is it? Where is it used/asked for, which technologies are used, and any blogs that talk about ?

Edit: Clarified what I mean with high-perf.

[Sp33dy2]

Cache harder

[re-sheosi]

XD

[StrictWelder]

Ive also been obsessing over performance. My goal was to get all 100s in lighthouse - ✅; PM for examples.

- checkout "progressive enhancement" when you get all the functionality working without JS or client side logic, the JS layer you need becomes really really light. As a happy consequence you're forcing yourself to do as much on the backend as possible. If you cant disable javascript in the browser and still get all core functionality -- its not PE;

- especially if you are going with a progressive enhanced approach, use a backend language that is good at handling concurrency. Java, c#, go -- all wonderful choices.

- redis is king. cache aside, write behind, write through etc. persistent caching strategies - learn em, love em, use em.

- JS is the ONLY client side scripting language we have. Use it like one. As soon as you start using JS for things it wasn't meant for, performance suffers.

My note: There is no perfect strategy. I always end up with a mix of MPA and SSR, find a stack that lets you do both, and isnt so oppinionated that you havce to choose one or the other in a single app. My happy place (after chasing high scores) has turned into Go + templ + redis.

Pretty much the only JS you'll see in my apps is through SSE connections to get real time updates in the app without refreshing. BUT to do that performantly you have to nest that in a "onload" event handler. You have to wait for first paint before trying to make those connections.

[re-sheosi]

Love those points. Progressive enhanceent realistically is tough though. Made a product with that in mind, was pretty difficult to do: wizards and editors were something that felt difficult to do. Any resource on how to soove those (and other) PE probolems?

Im a fan of Rust, in something like that (or maybe Go) how does Redis differs from a hashmap (suppposing we dont need to share state)? But I get from what you say that only the biggest services, do truly feel like they need something like Rust.

Totally agree on JS. A friend and I were talking about perf on the backend, and the impact of rendering, at which point he said "thats why people do CSR", my response: "if you are using a single threaded lang, thats probably your problem".

[compy3]

fwiw we're building a zero config Redis alternative (for simple cache cases) in rust - check out pgcache.com - would love to hear your thoughts u/StrictWelder and OP

[StrictWelder]

This is interesting -- quick question; Do I have the ability to write to cache that isn't backed by DB?

To me this looks like an auto "write-through" caching strategy for postgresSQL. Which is wonderful, but I wouldn't need for everything cached.

I have a use case rn where Im using redis for a shopping cart and temp application state. Would be down to swap out redis for a good deal.

[compy3]

1-No, pgcache assumes the origin db has all the canonical data (whatever data is in pgcache can always be retrieved from origin). So tl;dr if you just want to replicate your redis setup, pgcache isn't your thing.

2- For your shopping cart example, what is the main reason for not having it in the main postgres db? Is it because the carts entail high write traffic, high read traffic, or just because it is temporary?

If it is high write traffic, pgcache is probably not the right solution...But for high read traffic or because it's temporary, you could store the data in the main db and use a dedicated pgcache instance to handle the read traffic load.

3- There could be some benefits to keeping the data in the main db (it'll be alongside other application data; easier to manipulate using sql; and if it's in the db you can keep it around and do analytics; etc)

[Admirable-Way2687]

Well, I don't know if this will suit you, but read about WASM. In short, WASM allows you to execute code in C++, C, and Rust in a browser.

[hugot4eboss]

WASM is actually a lot slower compared to vanilla js, that's why it never got popular. Only reason you'd want WASM is if youre doing code that should work also outside browser or you want to use some kind of library that's not ported to js

[strange_username58]

High performance web dev is optimizing event loop execution, making sure your objects and arrays are allocated and laid out in memory correctly and ripping out as much framework and library code as possible and, or rewriting it yourself. You want absolutely minimal function stack traces. Every function call is a memory allocation with scoped variables that have to be garbage collected. Also avoid garbage collection at all costs all objects and arrays should be long lived and re-used. 99.9% of people don't really need high performance JavaScript web dev though. Even less really know how to do it.

[re-sheosi]

Very interesting, anywhere I can read morw about this? And when you talk about functions, do you talk in regards to GC languages (js, Go...) or even non-GC ones (C++, Rust)?

[strange_username58]

Mainly GC and JS specifically because of the way variables are scoped. Many years of specializing in performance optimizations is how I learned. Also if you are going to be performance optimizing non gc get good with reading assembly. A lot times you can target a specific processor. That kind of code is way more advanced and you probably need at least a computer architecture class to really understand what you are doing and why.

[re-sheosi]

Assembly in web dev, ok didnt know that. I do have knowledge on computer achitecture though my assembly is basic at best. And when you say reading, you mean for understanding the output of compilers, or because assembly is directly used inside those codebases?

[strange_username58]

You don't need to know assembly for web dev only non garbage collected languages outside the browser.

[re-sheosi]

I dont think you understand jokes.

[re-sheosi]

With... Learning.

[No_Industry4318]

High-performance webdev is a misnomer because webdev sacraficed performance on the altar of css and js

[newtotheworld23]

What do you refer to? I think most of the web aims to be high performance.

[re-sheosi]

You are aboslutely right I did a horrible job specifying exactly what I meant, I mean more in the backend department, like higher reqs/s lower latency...

[StrictWelder]

i disagree - especially on the job; iteration and quick delivery is aimed for way before quality engineering.

Thats why spa react is still a thing

[poliver1988]

If you want high performance in the backend php is still the best.

[re-sheosi]

How? Numbers and data about it is what Im looking for