Decision #1
Postgres over Kafka for the multi-agent event bus
Context
When we built the Multi-Agent Manufacturing System, the obvious answer for inter-agent communication was Kafka. We picked Postgres.
Why we made this call
The client already ran Postgres. Their ops team had years of muscle memory with it. Latency requirements were 'sub-second', which Postgres handles trivially. Kafka would have added a 4-week setup tax for zero functional gain.
What we learned
When the obvious answer adds operational complexity without buying performance you need, the boring answer is correct. We default to Postgres for event buses now and only reach for Kafka when message volume genuinely demands it.