Architectural patterns I’d master if I had to design systems that scale:

1.CQRS & Event Sourcing

2.Saga Pattern

3.Strangler Fig Pattern

4.Bulkhead Pattern

5.Transactional Outbox

6.SEDA (Staged Event Driven Architecture)

7.Orchestration vs. Choreography

8.Sidecar Pattern

9.LMAX Disruptor (ultra-low latency queues)

10.Backpressure

11. Leader-Follower Replication

12.Event-Carried State Transfer

13.Temporal Workflow Pattern.

14.Dual Write Avoidance (beyond transactional outbox)