[thiago_fm]

I have the feeling you are struggling to accept that you failed on that process because of your expectations and are looking for validation that you aren't a terrible developer, given that you even shared the age you started coding as if you need to show us social proof. So you've written that post to help deal emotionally with that problem. So no, you aren't a terrible developer, does it help you feel better?

First of all, recruitment and processes are random, have you interviewed enough? Most people old enough have interviewed for 100+ companies, and with experience you learn that doing well doesn't mean you'll get a job.

We're also in some sort of tech recession for non-AI jobs. Many companies keep their job positions posted and interview people but don't hire them, as they'd like to keep recruiters and the team busy. I know this because I'm in a leadership position and talk with many colleagues who are also in other companies leadership position. (not that my company is doing that, though)

There's another reason, you might think you have ace'd it, but the interviewer might have different expectations, also, just by solving the solution or problem it doesn't mean you are fit for the company, sometimes we think we aced it, but they expected a different solution that you didn't know. Dunning kruger effect?

You've mentioned yourself that you've done 75% in a few, this might be enough for they to chose a different candidate.

Also, if your CV is weak, they might have changed their minds, not every company wants to train people, management could have pushed a different direction to the recruiting process or just the budget could have been closed.

To sum up, just move on and don't waste time on this, maybe focus on studying more? Nothing in life is guarantee'd, you might study years and never get that HFT job, or you might get it. That's life. Thinking about it won't get you the job, what you can do is practice more until you make it.

[throwaway12412]

First of all, thank you for providing this feedback, this is exactly what I was looking for!

I'm very confident in my own skills and I feel like I have a fairly ok gauge on what kind of level of developer I am. I am definitivly above average, but I am no guru or savant. I shared that I had been programming since I was young to try to back up the claim that while my CV might not reflect it, I've been doing low latency, highly optimized stuff for a while.

I have about 6 yoe at this point, and I've interviewed several times, but in this round I've only gotten two oppertunities to talk to an interviewer. I shared this also in the post, to back up that my CV is indeed weak. My post is not about trying to come to terms with that I didn't get the job, but more that I find it very strange that I, in my opinion aced the test and was then let go.

Obviously with a NDA and without a recording I cannot back that up, so I fully understand that you choose to doubt this. It was a very simple problem in a domain I've worked in. I've discussed this sort of setup with other developers before and ran benchmarks. I'm fairly certain that what I implemented in those 40 minutes represents close to a perfect solution, given the circumstances.

And I could not agree more with the last line, I have and continue to dedicate most of my freetime to upskilling. I'll be looking to build more projects for a better portfolio, I'm in the process of making my first contributions to GCC and Clang, and I Hope to give some conference talks either this year or next year.

I mentioned it in a post above, but I really view this as being on my technical or interviewing abilities as the best possible outcome, because it means that I can course correct and come back stronger :)

Once again, thanks for taking the time to answer, I really appriciate it!

[gsuuon]

It's been hinted at elsewhere but sometimes problems come in stages, and later stages are only revealed after finishing the first stage. If you've only finished stage 1 after 40 mins, they may be looking for the candidate who's already wrapped up stage 2 and is on to discussing improvements by that time.

[throwaway12412]

That is a very good point and something I didn't really consider. I've placed top 100 globally in advent of code a couple of times, so I do think my coding speed is relatively quickly, but maybe. Next time I'll focus more on speed, I was under the impression that showing your thinking and walking the interviewer through the thought process was more important.

Thanks for the feedback!

[thiago_fm]

I also thought about this in a few interviews and it wasn't the case. Often enough, the interviewer won't make this clear so you have to ask.

I've had this situation in a company where the interviewer told me they would like to hear my reasoning, but then I failed, because I didn't do exercise 2 and 3 and wasted all my time talking about tradeoffs etc, when the interviewed seemed interested about it.

Those recruiting processes are garbage, if you take this into account, it will help you to succeed at it, you need to play the game, many times and then you'll make it.

Wish you a good time on that career change, I myself, have given up and instead just accepted that I'll work with webdev for a long time, as recruiters and companies seem to be too concerned with experience to let a developer that worked on a different language or stack to work there and perform well.