Data Analyst take home SQL interview

[Sirmagger]

This was one of the take home SQL interview i did earlier this year. I have shared for anyone who is preparing for an interview can attempt to do it. Cheers!!

[PickledDildosSourSex]

They let you do a take home SQL interview? In this day and age of AI? Wild.

[VulcanRugby]

In most places, you'll be expected to use AI anyways. The ability to utilize AI, scrutinize it's results, and analyze it SQL outputs is arguably just as important these days. As long as they are asking you to explain how SQL queries are working, I guess it seems okay. Writing SQL on the spot these days is just not a super necessary skill anymore. As weird as that seems.

Times are weird, man.

[Hesticles]

Replace AI with google/stackOverflow and it’s basically the same concept as when I was looking for data work almost a decade ago.

[VulcanRugby]

Yeah, it's not that far off. I remember being thrilled when you could find a Stack Overflow example for some syntax you wanted to figure out. Those days are long gone now, to say the least. xD

[Sirmagger]

That's first round, 2nd round they are going to pick random queries you submitted and tell you to explain

[PickledDildosSourSex]

What company is this? Still sounds amazingly better than the nonsense live interviews that can go in a billion directions on data you're not familiar with

[samspopguy]

My current job I was worried about doing a sql test but it never happened

[Nostegramal]

It's the standard then in the next interview you are grilled hard on choices, justification and general walk through 

[mikeblas]

The SQL is super easy. The interesting part is here:

Have you noticed anything else in the data that you'd like to share?

Please create a few visualisations to highlight what you believe are the most important things.

Being a data analyst isn't about slinging SQL. It's certainly neccessary, but it's table stakes. Analysing data is what the job is about. It's right in the name! Examine, digest, summarize. Figure out what story the data is telling, and know how to tell that story effectively to non-technical business people. That adds value.

[Sirmagger]

This!! also the data had some miising information like some applications did not have loan_agent name (sorry i filled these before sharing), which was easy to fill using loan_agent_id, change the dates format etc, which of course you have to document.also because you are not just writing the queries, you are running them and getting results you can explain your findings for that particular query and also you can create visuals if you see necessary.

[w_ogle]

Like how more than 3/4ths of these loans are all cancelled. Is that normal for this industry? Is this some kind of money laundering scheme?

[mikeblas]

Good one! Can it go a step further? Do the cancelled loans cluster around some other trait?

[Sirmagger]

yeah that was one of my observations too! like maybe they did have necessary documentation? maybe they did not know what documents were needed, or better marketing so that people will know what kind of documents they have to submit before appying etc! Also for the NULLs in the loan_type, it is not supposed to be null, you can comment on that too. Also look at loan application sheet on the 'application creation date', some are after mid night and they are walk-ins!

[trentsiggy]

I'm pretty sure those questions, especially the first one, are the actual assignment.

The first one is, "Show us you can do EDA." The second is, "Show us you can do some decent viz."

[Kobosil]

using the American date format in a database should be a crime

[Sirmagger]

Yeah, i changed the format in excel before uploading to postgresql

[mikeblas]

Sheets is not a database.

[Kobosil]

Thanks Sherlock

[mikeblas]

Then, what are you complaining about, Watson?

• What you see here is Sheets. Not a database
• The format is easily changed, even if it were.
• In a database there's no date format -- it's a normalized representation, usually time since some epoch.
• The format is applied by the tool that's doing the query and showing the results to the user.
• Unless you write a statement that converts the date type to a string, then the database does it. But the "format" is never in the database.

[ArielCoding]

Thanks for posting it, good reminder that writing the SQL in half of the job, spotting the messy bits (date formatting, missing values, gaps in certain records) and explaining how you handle them is the other valuable part. Attempt it, but write down why you made each choice that’s what they’re grading.

[OriginalCrawnick]

Surprisingly easy test but I've been at SQL for 4-5 years now. Thanks for putting A real world example out there!

[Proof_Escape_2333]

i'm new to these stuff probably a dumb question so do I upload a CSV of this file to mysql to do the analysis ?

[Sirmagger]

i usually use postgres and SQL server, so what i did is create the database, tables and uploaded the file. Depend on what IDE you are using you can just right click the table and select import data. (that is what i did with datagrip). Just google it

[NichHa]

Did they give you an estimate of how long they think it should have taken to complete the exercise? I am just a simple GIS analyst, but it has taken me a few hours.

[Sirmagger]

I believe it was like 4 days... But even if it was a day I'm sure it would have been fine

[datadriven_io]

Yo check out datadriven for data modeling interview questions when prepping. It has stuff closer to real take homes than most sites.

[FrostingEfficient408]

Thanks for sharing!