Ask HN: How do I help a colleague who introduces a lot of typos?

It sounds, as you point out, that he is aware of the tendency to typos and has an idea on how to guard against it. I’ve built up a similar portfolio of techniques and best practices to guard against my own shortcomings, and most of the friction I encounter is when the team I work with doesn’t have the same viewpoints on correctness and tests.

Languages like Python are the worst for exacerbating issues. Perl at least would parse the entire codebase and do some validation. Python doesn’t evaluate until runtime, meaning that unless you have 100% test coverage of all functions and branches a typo could cause an issue long after the process started.

As others have mentioned it sounds like you co-worker has good ideas. Adding test coverage, being stricter about configs (don’t ignore known keys, validate structure … as much as people hat XML, DTDs are an amazing help for catching config errors) are all things that will pay off down the road.

Long story short, instead of looking at your coworkers suggestions as a way to guard against their mistakes, take some time to understand that they live in a more chaotic worldview than you do, and have strong experience in dealing with it. Heck, put them in charge of QA processes. They sound like they’ve got the experience, and will feel better when that experience is appreciated.

I think it all comes down to him testing his work, attention to detail, and taking responsibility for making it work, just like anyone else.

I don't really think "typo" is a useful word in this context. It's a sequence of characters that... _does not work_ and _was not tested_. The fact that it is close to a different sequence of characters that would work, or that a human could recognize it for that other sequence, isn't really relevant.

Some of the engineering approaches you mention can help, but at the end of the day he has to be responsible for verifying that things work. Tests, schemas, etc. can help, but you don't want to get into a game of "the test/linter/AI didn't catch this for me, therefore it is broken".

I've worked with plenty of people over the years with linguistic quirks, like spelling insisting on spelling "deliminator", or "pluggin", or whatever, but if the code works, it works.

If you’re using GitHub, you can use Copilot for an additional automated code review on pull requests. It’s very good at noticing typos, or refactoring issues. If you don’t Use GitHub, you can ask any LLM for an automated review before pushing (Claude Code is good at that but I assume they all work similarly).

LLM code reviews are rarely that useful but they’re good at catching the small stuff, I’ve found it to be a good addition to the normal review process

> I remember that i did not used to make typos but since a particular period that i vaguely rememebr i have noticed that i make more and more of them.

That "rememebr" has great comedic timing :D .. but as far as I can see it's the only typo too.

I've read that aging doesn't happen in a constant rate but at some ages it accelerates. I pride myself of having a high IQ but as I get older I notice the cognitive decline. I'm not being an elitist, but it makes me wonder if the way I feel now is what people with "slower" brains feel like all the time (I've only known what it feels like inside my own brain, obviously)

Systems and processes are good, but if the individual doesn't want to help make it better that is a different but related problem. Testing locally, checking work...that's the behavioral part of this he _can_ control. You can't force him, but might be able to encourage it, not by calling someone out in a code review/etc but privately discussing some local validation they could do. Also, I'm betting the "typos" aren't for corpus words but config strings like swmn0023094 or server names or whatever. That might be more of a custom dictionary type or DSL solution to check values against valid constant values.