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

Happy new year! Weird question but here goes. My colleague has a strong work ethic, works hard, learns fast, goes out of his way to increase test coverage etc. I would say his contribution is net-positive but some of his work causes problems, especially when it comes to config files, shell scripting etc., so everything that is not directly caught by a linter or spell-checker. His typo rate is quite high. I suspect an undiagnosed dyslexia. Mistakes are often caught very late, mostly in staging, making it cumbersome. It led to a few production outages. We have code reviews, a solid test suite etc. but typos are slipping through - once you make them, it's just harder for others to catch them. I feel bad for him because it already led to a blame game within the team, with some asking how one can be so sloppy. I don't suspect sloppiness because he is otherwise thorough. On the other hand, it escalated because the subject is very touchy with him. I suspect he is weirdly aware of the problem and in denial at the same time, and therefore extremely defensive. His take is that we should increase test coverage. It is part of the answer. However, once he's involved in writing the tests, the problem is shifted to writing correct tests. What I'm thinking about: - engineer the problem away: adjust our tooling and config mechanisms, less strings in our configs, less dynamically-typed scripting etc. - asking him to let AI review his code specifically for potential typos - increasing test coverage, with other people than him writing the tests What I am not considering: - Telling him I suspect he has dyslexia. I'm not a doctor. I'm trying to broaden my horizon on this issue, maybe I am missing something. What would you do? Edit: Example: A string value in a json config needed to be updated. On one prod instance, typo while updating the config by hand. Config validation of the software caught it, software stopped with the appropriate error message, a few minutes later we were up and running again. We introduced work reviews on prod instances (similar to code reviews) after that. Later, he then wrote a patch script to avoid making that mistake again. In the json schema definition used in the script, the name of the property had a typo (how it came to be... no clue, copy paste should have taken care of that). The script was part of a MR, the reviewer missed the typo. We noticed it in staging. We introduced tests for config editing scripts after that. And so it went on and on... The problem is not that it happens and we then refine our processes. It is the frequency.