My primary domain is functional programming and effect systems (effect/zio/rio) related, all of those communities have plenty (even too many) gathering places that are one google search away or the related libraries (for me would be effect-ts, typescript and some other microsoft tooling) have official discords linked on GitHub or docs.
Another good source of work are local meetups/communities chats.
Another good source of work are local meetups/communities chats.