Lessons

1HTTP, REST, and API design that survives clients50 min read

REST resources, status semantics, error envelopes, versioning, cursor pagination, rate limits, and async job patterns for LLM backends.

  • →HTTP and AI APIs
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2Data modeling, transactions, and when not to normalize52 min read

Entities and invariants, normalization tradeoffs, transactions and isolation, indexes, migrations, and modeling LLM runs for production.

  • →Backend Data and Performance
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3AuthN/Z: sessions, tokens, RBAC, service identity50 min read

Sessions vs JWT, OAuth altitude, RBAC and object-level authz, service-to-service identity, API keys, and agent tool authorization.

  • →Authentication and Authorization
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4Async work: queues, workers, retries, DLQs50 min read

Task queues vs logs, producer/consumer design, retries and backoff, leases, DLQs, lag/backpressure, and LLM worker operations.

  • →Asynchronous Work
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5Idempotency, exactly-once illusions, and webhooks48 min read

Idempotency keys, concurrent claim, webhook verification and dedupe, at-least-once consumers, and effect-once for billing and LLM runs.

  • →Retry-Safe Effects
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6Caching, pagination, and hot-path performance50 min read

Cache-aside and invalidation, stampede control, N+1 elimination, keyset pagination, HTTP caching altitude, and LLM-related cache choices.

  • →Backend Data and Performance
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7Logs, metrics, traces, and on-call for backends52 min read

RED/USE, SLIs/SLOs and error budgets, structured logs, cardinality, tracing across queues, alerting, and LLM-specific ops signals.

  • →Backend Reliability
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8Capstone: design a reliable LLM feature backend55 min read

End-to-end mock: Diff Explain SaaS — API, data model, authz, queues, idempotent billing, caching, SLOs, and a 45-minute self-scored rubric.

  • →HTTP and AI APIs
  • →Retry-Safe Effects
  • →Backend Reliability
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Skills in this course

  1. 01HTTP and AI APIsDesign stable resource, error, pagination, streaming, and long-work contracts.
  2. 02Backend Data and PerformanceModel transactional truth, indexes, migrations, caches, and projections.
  3. 03Authentication and AuthorizationApply session, token, service identity, tenant, and object-level access controls.
  4. 04Asynchronous WorkOperate workers with leases, backoff, DLQs, backpressure, and safe deploys.
  5. 05Retry-Safe EffectsMake requests, webhooks, jobs, model calls, and billing safe under replay.
  6. 06Backend ReliabilityUse logs, metrics, traces, SLOs, alerts, and incident practice to operate services.