Good question. The current network sustains 10k DAU. Perhaps a stretch goal to get to 100k DAU, right now. A few people working on scaling, but websockets is a newer architecture than proven REST systems, so new work must be done. Or perhaps a hybrid approach and caching services. One thing that is a problem in most places is large follower lists and pagination. Something like named queries or groups may be needed here. Other than that, I think most things can be overcome.