> not appropriate for a system that has performance requirements

What kind of performance requirements?

Write performance, Query performance, latency? Other?

Where was the bottleneck?

I've found it's very hard for other databases to beat Datomic for query performance.

> Another piece of advice would be to seriously consider if you need immutability in your database.

Remember to check with your audit team, your reporting and analytics teams, your business users, and your data warehousing team.