Echoing others, Chess engines certainly aren't a solved problem! In fact there are a lot of niches that are absolutely starving for effort. Ones I'm interested in are related to Chess variants and puzzles.
Fairy-Stockfish is a fork used by LiChess for the variants on the site, but it can now play a multitude of games from Xiangqi (Chinese Chess) to Shogi (Japanese Chess) to a crazy modern variants. There's a variety of tools to train new neural nets for these variants, generate opening books, puzzles, etc. You can play some of them on PyChess (pychess.org). These are projects basically run by a couple people with huge backlogs of bugs and feature requests. An enthusiastic developer can easily get involved! Or just enjoy playing different variants and getting involved with the player community.
If you happen to be a quiet place it will likely be easier to concentrate without the rain sounds. "Easier" in this sense is a bit relative, however. An environment with fewer external distractions will lead to a selection effect where you "catch" yourself more frequently and return back to the breath. Thus, you may feel like you're not concentrating well, since you "keep getting distracted." It's kind of like the Dunning-Kruger effect of the beginning meditation :)
On the other hand I find music and background conversations especially distracting and like to listen to pink-noise or other non-varying noise sounds to make concentrating easier.
I'm not the OP, but it is an important distinction, breath control (pranayama) is yogic.
While I can't speak for other traditions that feature meditation, at least in Theravada Buddhism, training of the breath is an essential part of the practice for the development of mindfulness (sati), beyond "observing the breath as it is." This gets de-emphasized in the modern vipassana movement focusing on "bare attention", but canonical interpretations of the Anapanasati Sutta [1] on the mindfulness of breathing to indicate that one only uses bare attention to "discern" long and short breaths, but "trains" oneself to become aware of the whole body, to calm bodily fabrication, and the rest of the items on the list. This is taken to mean that one can use right effort to breath in ways that are conducive to being aware of the whole body or ways of breathing that calm bodily fabrication, etc. So, while definitely not as gross as counting fixed durations like on the site linked, exerting oneself to influence the breath has a place in at least one very prominent non-yogic tradition.
Fairy-Stockfish is a fork used by LiChess for the variants on the site, but it can now play a multitude of games from Xiangqi (Chinese Chess) to Shogi (Japanese Chess) to a crazy modern variants. There's a variety of tools to train new neural nets for these variants, generate opening books, puzzles, etc. You can play some of them on PyChess (pychess.org). These are projects basically run by a couple people with huge backlogs of bugs and feature requests. An enthusiastic developer can easily get involved! Or just enjoy playing different variants and getting involved with the player community.