Write path · Go · cmd/api + cmd/worker

Scalable & Low-Latency Go System Design

Click i on a plane for the whole step, or on a box for its Go. Zoom in like a map for streets — G-M-P inside each Go process, patterns around the TX, row locks vs mutexes.

Idle

Which layer helps

1Client / app

POST /v1/invoices
Idempotency-Key

2Load balancer / gateway

TLS · routing · rate limit

3Go API servers

cmd/api · HTTP fleet

api-1api-2api-3

cacheRedis

Idempotency · RL

readReplica

Catalog · tax

AInput validation

Schema · reject first

BAuthn / Authz

Tenant · RBAC

CCreate invoice

errgroup fan-out

DDatabase transaction

BEGIN · FOR UPDATE · COMMIT

dbPrimary DB

Write + row locks

ECommit successful

201 now · events after

201API response

Fast ACK

evtOutbox row

Same TX as write

pubOutbox relay process

cmd/relay

FBroker / queue

Dedicated cluster

broker-1broker-2broker-3P0 emailP1 pdfP2 analytics

GGo worker servers

cmd/worker · not API

worker-1worker-2worker-3NotifyPDFAnalytics

dlqDead letter

Poison · replay

72%Overview

Zoom in like a map · streets: G-M-P, patterns, locks

Why Go helps