Some general rules make sense for common use cases. Like, I'll say that a relational DBMS is generally what you want rather than a graph one. For a single-node

Some general rules make sense for common use cases. Like, I'll say that a relational DBMS is generally what you want rather than a graph one. For a single-node DB, I'll always use Postgres if I have the choice. For a webserver, can't really go wrong with NodeJS, though you might have reasons to use something else (e.g. cost to run). But sharding is too use-case specific to prescribe something broadly like Spanner.