Yes, for all projects and small businesses I start, Postgres and Redis is what I use from the beginning. Then if it ever gets to the point where I need a differ

Yes, for all projects and small businesses I start, Postgres and Redis is what I use from the beginning. Then if it ever gets to the point where I need a different DB for something, I replace components with the new tool. People get fascinated with these fly-by-night data stores and put their operations at serious risk. Start with the tried and tested technologies, then carefully augment your stack as needed.