DOCUMENTDECK

Decoupling checkout

One idea per slide — why and how we moved order notifications to events.

Why now

Checkout was slow and brittle — three forces pushed us to act.

SECTION 01 · Drivers
Slow checkout
p95 hit 2.4s — three inline calls.
PAIN
Fails together
One downstream down failed the order.
RISK
Blocked squads
Every change shipped through us.
DRAG

The numbers

SECTION 02 · Metrics
2.4s
Checkout p95 before
▼ +1.6s
800ms
Target after
3
Consumers decoupled

The shape of the fix

SECTION 03 · Pyramid
PyramidPublish OrderPlacedCheckout returns the moment the event is outSubscribe independentlyEach consumer reacts on its ownReplay on failureThe bus is the recovery log

Where to invest

SECTION 04 · Matrix
2×2
QuadrantEffort →↑ ImpactLowHighHighLowEvent bus + DLQBilling consumerSelf-serve consoleDashboards

The plan

SECTION 05 · Roadmap
Q1
Q1 — Bus live
Q2
Q2 — Fan-out
Q3
Q3 — Self-serve