Solving the Jane Street reverse engineering challenge • Hacker News Board

Re: Solving the Jane Street reverse engineering challenge

#101

Post by pgn » Sat, Sep 05, 2026, 5:25 PM UTC

__atx__ wrote: post #13

anitil wrote: post #2

Hi HN, I recently solved the Jane Street reverse engineering challenge [0], and I wrote a blog post on how I reached the answer. It's a moderately technical and (hopefully) entertaining run through of the process. I hope you enjoy reading it as much as I enjoyed doing the challenge (though, as you'll read, it was also quite a frustrating process). My github is on the post if you were interested in seeing a bit more i…

> It turns out that this ‘sky130’ thing is like a … standard? Or something for making chips. Very cool seeing someone completely naive going into this :) If you want to read more about a bit more... cheaty way to do this, I have written about using formal verification machinery to straight up force the solution out of the netlist here: https://atx.name/electronics/asic-re/ . Could be a bit of an infohazard, but I thi…

> It's likely that this would now require actually reverse engineering the circuit subcomponents, but that is an entire rabbit hole I do not have time to go down at this point.

This is the route I ended up going! I posted my own writeup here: https://pradyun.net/blog/reverse_engineering.html

Re: Solving the Jane Street reverse engineering challenge

#102

Post by [deleted] » Sat, Sep 05, 2026, 5:28 PM UTC

eru wrote: post #100

anitil wrote: post #96

Earlier quoted context omitted.

I emailed them and asked as I'm in Sydney and didn't want to mess it up - they said to wait until the end of my workday, so I posted it at roughly 5:30 my time. I hope I didn't spoil it!

Their logistics were a bit weird: they asked not to post spoilers, but also ask you to link to your write-up. In any case, I had it all worked out already. But looking at other people's submissions today showed me that I found some easter eggs other hadn't. That was encouraging. (And I missed some that others found, of course.)

[deleted]

Re: Solving the Jane Street reverse engineering challenge

#103

Post by make3 » Sat, Sep 05, 2026, 8:29 PM UTC

anitil wrote: post #22

__atx__ wrote: post #13

Earlier quoted context omitted.

> It turns out that this ‘sky130’ thing is like a … standard? Or something for making chips. Very cool seeing someone completely naive going into this :) If you want to read more about a bit more... cheaty way to do this, I have written about using formal verification machinery to straight up force the solution out of the netlist here: https://atx.name/electronics/asic-re/ . Could be a bit of an infohazard, but I thi…

I'll definitely be reading this thankyou! I think this would have been a much better way to approach it, it's a bit of a joke in the piece that I always do things the hard way, but it's a genuine mystery to me why I operate this way. I should add I have an EE degree (but have never worked as an EE), so even though I don't know industry standards like this sky130 thing, it's not completely foreign to me.

Doing things the hard way is a lot of times "male" bravado (though this is not limited to males in any way ofc), this is a very common thing in junior engineers.

Curiosity is good but maturity is trusting that the problem will get hard at some point anyways, that improving the most efficient way is usually also interesting and is more likely to deliver desired things on time or at all, which can be a big deal if what you're trying to deliver it worth it, like.. a new MRI machine that detects new types of cancers, etc.

If you don't care about what you're trying to deliver, that's another problem that requires at least some questioning, though I understand people have families to take care of etc.