It really depends on how much data you need... I worked in an org where the primary data was in one database, and secondary data was in another. The DBA team wrote the query to call the other (remote) db across in part of the statement, and it was horribly slow... The N+1 pattern combined with memcached on the secondary lookups was so much faster in the end.. since it was limited to a display page worth of secondary lookups. A GraphQL server can relatively effectively do this for you.
In the end it really depends... if you're talking even 10-100k users, a single, well optimized SQL RDBMS is your best bet... getting past that takes deep knowledge and/or more options/skills. In the end, most don't have that next step and the trend to Micro-Service all the things is jumped to too soon in most cases (and not soon enough in others).
In the end it really depends... if you're talking even 10-100k users, a single, well optimized SQL RDBMS is your best bet... getting past that takes deep knowledge and/or more options/skills. In the end, most don't have that next step and the trend to Micro-Service all the things is jumped to too soon in most cases (and not soon enough in others).