pjacotg (u/pjacotg) - Readit News

pjacotg commented on Toys with the highest play-time and lowest clean-up-time joannabregan.substack.com... · Posted by u/surprisetalk

elboru · 2 months ago

Tip: Look for someone selling their grownup children’s Lego collection. I recently found a couple selling their children’s old Lego collection in Facebook Marketplace. I got an enormous bag of them for just a few bucks. It was a headache to filter out the garbage in them (small non-LEGO toys, unique pieces that were not really useful, a few mixed mega blocks, broken pieces, etc) but it was worth it, my children love them!

pjacotg · 2 months ago

I second this. I joined a second hand Lego Whatsapp group a while ago and that's made it far more affordable.

pjacotg commented on Ask HN: Is Mythical Man-Month still relevant in todays AI Vibe Coding world? · Posted by u/Codegres

pjacotg · 3 months ago

My key takeaway from the book is the importance of conceptual integrity and how hard this is to achieve the bigger the team. I think this is just as true today as it ever has been before.

pjacotg commented on Why I stopped using JSON for my APIs aloisdeniel.com/blog/bett... · Posted by u/barremian

pjacotg · 3 months ago

On the human readability concern, we use protobuf converted to text format. It looks JSON like so very readable and comes with all the other benefits of protobuf.

pjacotg commented on Ask HN: What does "legacy code" mean to you? · Posted by u/Arperb

shoo · 4 months ago

Michael Feathers, author of the book "Working Effectively with Legacy Code", [f] defined legacy code as code without automated tests.

From memory, the argument is that once you have automated regression/characterisation tests with sufficient coverage around the part of it you need to change, you're in a good position to attempt to make a change since you will be alerted if you are unintentionally introducing regressions. Without automated tests you can't efficiently and confidently make changes without significant risk of regressions. Feathers' book discusses testing and refactoring techniques to take OOP-ish application code that has no automated tests and get enough tests in place to let you change what needs to be changed in a controlled way.

A consequence of Feathers' definition of legacy code is that fresh code you wrote yesterday in a trendy programming language still gets classified as legacy code if you didn't also write the supporting test suite to help others maintain it in future! It's not a perfect definition, some might find it provocative, but it's both pragmatic and actionable.

A different take on legacy code could be something like Peter Naur's paper 'Programming as Theory Building' [n]. I don't believe Naur specifically discussed legacy code, but the rough idea is that each program has a corresponding theory (relating to the problem domain, organisational constraints, the implemented solution and its structure, alternative solutions that were considered and rejected, etc). Some of this theory can be written down in artefacts such as design docs, requirements or comments in the code, but for a software project to be alive, the theory needs to live inside the heads of enough of the team who are building and maintaining the software. If that is lost (e.g. the team departs and a fresh team is hired to replace them) then no one in the new team may understand the "theory" so the software project is effectively dead until the new team learns the problem and solution space and develops their own new theory.

I'd regard such a "dead" software project where none of the current maintainers understand the theory behind the existing code as being legacy code -- but this is a joint property of the people working on the codebase and the artefacts (source code, design docs etc), it isn't a property of the code base in isolation. Maybe "legacy code" is the wrong way of framing it as it misses the importance of the relationship between the maintainers, the codebase and the surrounding context, and something like "dead project" is a little more helpful.

[f] https://www.oreilly.com/library/view/working-effectively-wit... [n] https://pages.cs.wisc.edu/~remzi/Naur.pdf

pjacotg · 4 months ago

I was going to mention Peter Naurs paper as well. It's fundamentally changed the way I think about software. The projects I've seen that are in the most trouble are those where the current devs haven't had the opportunity to work closely with developers that understood the codebase well.

pjacotg commented on Ask HN: How does one stay motivated to grind through LeetCode? · Posted by u/blutoot

pjacotg · 4 months ago

Have a look at a site called neetcode. They offer collections of leetcode problems that are representative of what you'd see in an interview. They have tutorial videos for each problem, which should help you get back up to speed with these sort of problems.

pjacotg commented on Mathematicians have found a hidden 'reset button' for undoing rotation newscientist.com/article/... · Posted by u/mikhael

noobermin · 5 months ago

The article is here.

https://arxiv.org/abs/2502.14367

Sorry, but the existence of such an inversion still is interesting from a mathematical perspective. It isn't "of much use" practically without the inversion formula/calculation, but that's ok. "There exists" is still a fascinating fact.

pjacotg · 5 months ago

Completely agree. Beyond being of interest in its own right, "There exists" is a prerequisite for further work in finding a practical approach to find the path.

pjacotg commented on Ask HN: What to do with a pure mathematics degree? · Posted by u/mareoclasico

pjacotg · 7 months ago

In regards to a career as a quant, the top firms may focus on "young geniuses" but there will be plenty of places where your profile would be just fine. It's a broad industry!

pjacotg commented on Ask HN: How do you keep your SWE skills sharp outside of work? · Posted by u/myanonymousacct

rpearcea · 8 months ago

Build side projects if you have the time. For example, I have a computer algebra system hosted online. Every week I add a couple of algorithms just by working on it when everyone else has gone to bed. Sometimes I get a lot done, sometimes not a lot, it varies. But it has definitely stopped atrophy.

pjacotg · 8 months ago

That sounds interesting. Do you have a link?

pjacotg commented on An Introduction to Stochastic Calculus (2022) bjlkeng.io/posts/an-intro... · Posted by u/ibobev

LostMyLogin · a year ago

Does anyone have a solid road map of what to learn to get to the point where learning stochastic calculus is possible? I have a CS degree that was obtained 8-10 years ago. What are the prerequisites?

pjacotg · a year ago

There's a book on financial calculus by Rennie and Baxter [0] that gave me very good intuition on the ideas behind option pricing. It starts with the binomial model and moves on to using stochastic calculus. If you get into the topic you'll want to read more in depth books, but this may be a good place to start.

[0] https://www.goodreads.com/book/show/307698.Financial_Calculu...

pjacotg commented on Big Book of R bigbookofr.com/... · Posted by u/sebg

epistasis · a year ago

CSV seems to be a natural and easy fit. What advantage could parquet bring that would outweigh the disadvantage of adding two new dependencies? (One in Python and one in R)

pjacotg · a year ago

Not the op, but I started using parquet instead of CSV because the types of the columns are preserved. At one point I was caching data to CSV but when you load the CSV again the types of certain columns like datetimes had to be set again.

I guess you'll need to decide whether this is a big enough issue to warrant the new dependencies.