Signs it is time to revisit event-driven architecture

This is cheap to get right at the start and expensive to retrofit. A few signals that event-driven architecture is due some attention.

Architecture is the set of decisions that are expensive to reverse, which is the only reason they deserve the name. If it only works because one person remembers to do something, it does not work yet.

The signals

• Nobody can say when it was last reviewed
• The answer depends on who you ask
• Events decouple producers from consumers, which is the whole point
• Debugging gets harder the moment nothing is synchronous

What good looks like

Start with one event, not with an event bus. The teams that handle this well are rarely the ones with the biggest budgets. It is worth deciding this deliberately rather than inheriting whatever the last person set up.

In practice

The right architecture for a team of three is the wrong one for a team of thirty, and vice versa. Three things worth confirming about event-driven architecture before you move on:

• Someone can say what the current setup is without going to look
• Start with one event, not with an event bus — and you know whether that is true here
• There is a way to tell whether the last change to this helped

Worth checking on your own setup before it becomes someone else's problem to fix.