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Ask HN: What's the hardest problem you've ever solved?

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Re: Ask HN: What's the hardest problem you've ever solved?

#211

Post by anon2775 »

Convincing a department to graduate me with an ABET accredited degree without finishing all coursework. It was significantly easier than deriving the time-dependent wave equation for hydrogen, writing a Java-to-MIPS compiler with two implementations, one in C++ and one in Java, and making an UNIX FORTRAN reactor simulator compile on Windows 95 (lol!)... all with crushingly, untreated depression. Also, survived the Loma Prieta earthquake and Paradise Camp Fire... nothing special there though.

My friends: getting an ASW account while being neither rich nor famous; another, coming into possession of a MiG-21. /unhumble-brag

Re: Ask HN: What's the hardest problem you've ever solved?

#212

Post by bpye »

herodotus wrote: post #197

When I was a CS prof, many, many years ago, our undergraduate lab had Macs with floppy disks. I asked the University to pay for installing 10MB Hard Drives in the Macs. I was asked to present my case to the deans council. At the meeting, I said that the students used the floppy to load their development environment. I said that, with a hard drive, it took 10 secs to load and be ready. With the floppy, I said it took…

Working on anything with 10s of seconds or even forbid minutes of delay is infuriating, yet unfortunately sometimes unavoidable.

Re: Ask HN: What's the hardest problem you've ever solved?

#213

Post by _Nat_ »

iliis wrote: post #165

What a fun question :) And there are some very cool answers! A few things that come to mind from my life, from back when I was still a kid/teenager: - Building a three-way marble-track switch. There are many marble tracks that have these two-way switches that alternate between two tracks, like this one here: https://theworkbenchutah.files.wordpress.com/2013/04/06-marb... I wanted to build one that would evenly distri…

The "linked variables" concept is often called ["reactive programming"](https://en.wikipedia.org/wiki/Reactive_programming) or ["data binding"](https://en.wikipedia.org/wiki/Data_binding).

And you're right that it's very helpful with GUI specification.

Re: Ask HN: What's the hardest problem you've ever solved?

#214

Post by ComputerGuru »

shaklee3 wrote: post #190

I eventually solved a bug that took about 1.5 years to figure out, since we were not able to reproduce it, and it only happened on a customer's system. Long story short, it ended up being a by-product of sending a (256*N)+1 byte packet through the system, and the fpga asserted a signal 2 clocks later that did not assert in time on those sizes. This resulted in a single buffer leaking, but eventually it built up expon…

I feel you. A bug in our recovery software would result in the live CD being unable to open the Windows kernel file after having located it on disk. No amount of logging we added to the code made sense. In the end, after more than a year, there was a customer in the UK that could reproduce the problem each time on a clean Windows 10 install (so no private info). I mailed him a new SSD to replace his old HDD and paid for him to overnight me his hard disk. Problem solved the very next day.

Re: Ask HN: What's the hardest problem you've ever solved?

#215

Post by bpye »

yholio wrote: post #90

I somehow decided I needed to cheat to pass a certain exam because I was basically crap at memorizing stuff. So I used an analogue wireless headphone, an induction loop around my neck and a mobile phone. Since I lacked an accomplice to dictate, I read aloud the hundreds of pages and recorded myself, careful to preserve and properly serialize things like complex formulas. This was before the era of iPods and SDCard pl…

I was always tempted to modify a calculator to add Bluetooth, then I could stream over whatever data I wanted from a phone somewhere without any suspicion. Graphic calculators make this trivial as they often have a serial port, I just never got around to building it. I guess I didn't want to cheat that badly

Re: Ask HN: What's the hardest problem you've ever solved?

#216

Post by legohead »

wolco wrote: post #209
mrleinad wrote: post #143

Earlier quoted context omitted.

Hey, Kevin Mitnick still gets hired today, doesn't he?

As a public speaker and author mostly. He doesn't get access to state secrets and hasn't been employed by any other company. He wouldn't get a call back from McDonalds if he applied.

He's hired as a pen tester and gains access to companies, their secrets, etc. I have a sysadmin friend whose company hired him to pentest, and they kept in contact.

Re: Ask HN: What's the hardest problem you've ever solved?

#217

Post by dharmab »

antisugar wrote: post #74

I’m surprised and slightly disappointed that my memories don’t bring up a clear answer to this. The hardest problems I’ve faced were never exactly solved, just moved past or muddled through. Things like loss of close friends and family, acknowledging my own limitations, and accepting the inertia of flawed institutions. Any problem that eventually found a solution I remember as feeling relatively simple in retrospect.

Agreed on the technical problems- the "hard" problems in my career have been massive degradations/failures with no error messages, which are typically solved with liberal application of strace, gdb/pdb, iproute2/ss and Wireshark. Once you find the smoking gun in the kernel or on the wire then it becomes simple again.

I guess the hardest problems I've ever "solved" (mitigated) were mental (depression/anxiety/impostor syndrome). But those aren't one and done happy endings- they're a bundle of general anxieties that are never fully resolved. You just learn how to manage.

Re: Ask HN: What's the hardest problem you've ever solved?

#218

Post by IloveHN84 »

Recognizing face expressions of babies born before the expected date and put in incubators with oxygen masks. The problem is really hard and the collection of video material available prevents the usage of machine learning techniques, so old school algorithms perform much much better.

Re: Ask HN: What's the hardest problem you've ever solved?

#219

Post by sinuhe69 »

herodotus wrote: post #197

When I was a CS prof, many, many years ago, our undergraduate lab had Macs with floppy disks. I asked the University to pay for installing 10MB Hard Drives in the Macs. I was asked to present my case to the deans council. At the meeting, I said that the students used the floppy to load their development environment. I said that, with a hard drive, it took 10 secs to load and be ready. With the floppy, I said it took…

Absolutely brilliant!

Re: Ask HN: What's the hardest problem you've ever solved?

#220

Post by egeozcan »

whack wrote: post #35
mooreds wrote: post #19

I was working on a calendaring system. We supported recurring events, and each event could also have a piece of equipment associated with it (one or more). Events could also be changed, either the current event or this and every event. Event start/stop times were stored in UTC, but the event was displayed in the users timezone, and could cross daylight savings time boundaries. This was done with a mix of javascript o…

How did you handle the database storage for recurring events? Did you have just one entry that represents the recurring event as a abstract whole, or a database entry for each instance of the recurring event? The former seems "better", but you also run into a whole lot of complications: 1) The user can delete specific instances of a recurring event. Eg: delete the event for thanksgiving Thursday but leave it intact f…

This is a good read about recurring events: https://martinfowler.com/apsupp/recurring.pdf
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