Every few years, I re-write my Go game in another language. In 2014 it was JavaScript, in 2016 it was Ruby, and in 2019 it is Rust, because OMG this language is amazing.
Instead of separating the board and graph data structures, I am making a single graph with a node list and an edge list. Looping over those lists will still be fast, since the boards only go up to 19x19.
The Graph type should be able to render itself as Graphviz.
When playing with others, we can connected two players through WebSocket, and do the validation of the move on the client side and the server side by compiling to WebAssembly on the client, and compilation to ordinary machine language on the server side. Both sides will use the same code, and all the code will be covered by Rust tests.
It's fast, tooling is great, it compiles very nicely to WebAssembly, which did not exist when I started writing Go Games.