Backend Engineering · 300-level
Backend Engineering: Systems That Scale
A staff-level deep dive into the backend: API contracts, data modeling and query performance, caching, async and event-driven flows, reliability, security, observability, and the economics of scaling.
BEN-3013 creditselectiveno prerequisites
What's inside
Sections & lessons
01
HTTP & API design
- Choosing between REST, gRPC, and GraphQLconcept40 min
- Status codes and error contracts clients can act onconcept35 min
- Versioning and pagination that survive scaleconcept40 min
- Idempotency keys for safe writesconcept40 min
02
Data modeling & databases
- Relational modeling: normalization vs denormalizationconcept40 min
- Indexes the query planner will actually useconcept40 min
- Reading query plans with EXPLAIN ANALYZEdemo40 min
- Transactions and isolation levelsconcept45 min
03
Caching & performance
- Cache layers and where to put themconcept35 min
- Cache invalidation without serving stale dataconcept40 min
- The N+1 query problem and batchingconcept35 min
- Connection pooling and the database connection limitconcept35 min
04
Async, queues & event-driven
- Message queues vs pub/sub, and when to go asyncconcept40 min
- Delivery semantics and idempotent consumersconcept40 min
- The outbox pattern and the dual-write problemconcept40 min
- Backpressure and consumer lagconcept35 min
05
Reliability & correctness
- Idempotency as a system-wide propertyconcept35 min
- Retries with exponential backoff and jitterconcept40 min
- Timeouts, deadlines, and budgets across a call chainconcept35 min
- Circuit breakers, bulkheads, and graceful degradationconcept35 min
- Distributed consistency: replicas, read-your-writes, and sagasconcept40 min
06
AuthN / AuthZ & security
- Sessions vs JWT: stateful and stateless authconcept40 min
- OAuth2 and OIDC: delegated access done rightdemo40 min
- Authorization models and object-level accessconcept35 min
- Input validation, secrets, and common backend vulnerabilitiesconcept40 min
07
Observability
- Structured logging and correlation IDsconcept35 min
- Metrics: RED, USE, and reading distributionsconcept35 min
- Distributed tracing and context propagationdemo35 min
- SLOs, error budgets, and debugging in productionconcept35 min
08
Deployment, scaling & cost
- Horizontal vs vertical scaling and stateless servicesconcept40 min
- Database scaling: replicas, replica lag, and shardingconcept40 min
- Progressive rollouts and backend cost controlconcept35 min
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