I migrated the server to Apollo v2 in this branch: https://github.com/aerogear/aerogear-data-sync-server/tree/apollo-v2
I also have done an initial work on hot deployment on v2. Latest commit in that branch is for that.

However, we don't know what would happen with the subscription server and the open websocket connections with that approach on that branch. So, asked it an Apollo community Slack and created an issue: https://github.com/apollographql/apollo-server/issues/1275

Hot reload on v1 is relatively straight forward: https://github.com/aerogear/aerogear-data-sync-server/tree/hot-schema-poc
But, I think that's also not tested with the subscription server and the open websocket connections.