10 parts · 12 chapters

Backend Architecture and Scale

The backend mirror of the Frontend Architecture course: how to shape a backend so that many teams can change it safely for years. Architecture is mostly about boundaries: which code may call which, which service owns which data, and which failures stay contained.

Ten parts: choosing between a monolith, a modular monolith and services honestly; hexagonal and clean architecture in real TypeScript; DDD tactical patterns; data ownership and service boundaries; event-driven architecture, choreography and orchestration; synchronous versus asynchronous integration; multi-tenancy designs; and three incident logs written the way post-mortems are: the distributed monolith, the shared database and the event storm.

Start reading · Part 0 Present as slides
monolith to services · hexagonal and clean architecture · DDD tactics · data ownership · events · sync vs async · multi-tenancy · three incident logsmid → staff · backend engineers and tech leads
shapeMonolith, modular monolith or services, chosen by team and change pattern.
insidePorts and adapters, aggregates, repositories, domain events.
boundariesOne owner per piece of data; contracts between owners.
integrationCalls versus events; choreography versus orchestration.
tenantsPooled, bridged and siloed tenancy, and noisy neighbours.
failureThree incidents that come from architecture, not code.
00

Monolith, Modular Monolith, Services: Choosing Honestly

Shapes and their costs · Extracting a service: the strangler fig
2 ch · ~12 min01

Hexagonal and Clean Architecture in Real Code

A use case with ports
1 ch · ~8 min02

DDD Tactical Patterns

Entities, value objects, aggregates · Bounded contexts and translation
2 ch · ~12 min03

Data Ownership and Service Boundaries

Owners, queries and read models
1 ch · ~8 min04

Event-Driven Architecture: Choreography and Orchestration

Events, commands and state
1 ch · ~8 min05

Synchronous versus Asynchronous Integration

Sync chains multiply failure
1 ch · ~8 min06

Multi-Tenancy Designs

Isolation enforced in the database
1 ch · ~8 min07

Incident Log: The Distributed Monolith

Timeline and lessons
1 ch · ~8 min08

Incident Log: The Shared Database

Timeline and lessons
1 ch · ~8 min09

Incident Log: The Event Storm

Timeline and lessons
1 ch · ~8 min
Built on System Design and Distributed SystemsUses Backend System Design for components, Distributed Systems for failure, and Ledgers for the running payments example.