Is this comparable to Sea star [0]?

[0] https://github.com/scylladb/seastar

I just took a look a both (thanks for the pointer to seastar! cool project). I'd say "sort of but not exactly". It seems like two approaches to solving the same problem.

Silk seems like mostly a scheduler that uses C++'s native coroutines. Seastar is a future-based framework. Both contain a scheduler and enable async coding patterns.