OptiChess
A chess engine written in C++, with its own analysis interface and a bot that plays on Lichess.
The engine and its interface are written from scratch in C++ with raylib: the search, the evaluation, the rendering, down to the pieces, which I drew by hand. There is no piece of Stockfish inside, and no asset that came from anywhere else.
The search is a tree exploration of my own design rather than the alpha-beta most amateur engines settle on. In chess that is the harder road, which is precisely what makes it interesting. The evaluation is still hand-written: material, pawn structure, king safety, activity.
It runs as a bot on Lichess under the name Grogros_Zero, so it has to hold up against real opponents, at real time controls, over a real protocol — not just on my machine.
It is the oldest project I still work on. Started in 2022, preceded by a first engine in Python, it predates every AI tool I use today: this one I wrote by hand.