LEVEL 14 · ZUDOJS

Course Advanced

ZudoJS advanced systems

Events, messages and CQRS, queues and schedulers, serialization, RPC, API operations and OpenAPI, then testing, logging, observability and documentation, and platform features: feature flags, tenancy, plugins and adapters.

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When you finish, you can

  • Decouple features with events and messages
  • Separate commands from queries
  • Move slow work to queues and run work on a schedule
  • Serialize values across services and call them with RPC
  • Describe the API in an OpenAPI document generated from its schemas
  • Hide external systems behind adapters and extend an app with plugins
  • Roll out features gradually and isolate tenants
  • Test, log, trace and measure a ZudoJS application

You build: An event-driven, observable Task API with background jobs and feature flags

MODULE 1

Events, messages and CQRS

  1. 1EventsDecouple Task API features with events: handlers, wildcards, priorities, sequential and parallel dispatch, middleware and handler errors with @zudojs/events.40 min
  2. 2MessagingAsk another part of the Task API to do something and get an answer back with @zudojs/messaging: messages, middleware, correlation ids, timeouts, cancellation.35 min
  3. 3Commands and queries (CQRS)Split the Task API into commands that change data and queries that only read it: buses, handlers, middleware, execution context, results with @zudojs/cqrs.40 min

MODULE 2

Background work

  1. 4Background jobsMove slow, unreliable work out of the request into a job queue: jobs, processors, workers, concurrency, retries with backoff, dead letters with @zudojs/queue.45 min
  2. 5Scheduled tasksRun work on the clock, not a request: intervals, cron expressions, time zones, retries, overlapping runs and running on one instance with @zudojs/scheduler.40 min

MODULE 3

Services and contracts

  1. 6SerializationTurn values into text and back without losing what they were: Dates, BigInts, Maps, Sets, bytes, custom types and versioned payloads with @zudojs/serialization.35 min
  2. 7Calling services with RPCCall a function in another service as if it were local: procedures, clients, transports, validation, errors, identity, timeouts and retries with @zudojs/rpc.45 min
  3. 8One operation, many transportsWrite business logic once as an operation with @zudojs/api, then run it from HTTP, RPC and a queue with the same validation, errors and timeouts.45 min
  4. 9OpenAPI documentsDescribe the Task API in an OpenAPI document with @zudojs/openapi: schemas as components, OpenAPI 3.0 or 3.1, validation, JSON or YAML, a docs page.40 min

MODULE 4

Quality and insight

  1. 10Testing a ZudoJS appTest the Task API with Vitest and @zudojs/testing: a test clock, mocks and recording buses, a test container, ordered cleanup, and real HTTP integration tests.Core45 min
  2. 11Testing a ZudoJS application layer by layerTest the Task API one layer at a time with Vitest: services, PGlite repositories, auth sessions, events and queues, CQRS buses, HTTP routes and a full workflow.60 min
  3. 12Structured loggingReplace console.log with structured entries a program can search: levels, child loggers, request ids, redaction and JSON logs with @zudojs/logger.40 min
  4. 13ObservabilitySee inside a running Task API: metrics count what happens, traces show where time goes, and logs share one trace id with @zudojs/observability.Production45 min
  5. 14Documentation as data with @zudojs/docsTurn the Task API's Markdown docs into checked data with @zudojs/docs: documents, frontmatter, a registry, link and navigation checks, and generated output.50 min

MODULE 5

Platform

  1. 15Feature flagsTurn features on and off without deploying: rules, evaluation context, percentage rollouts, A/B variants and kill switches with @zudojs/feature-flags.40 min
  2. 16Multi-tenancyServe many companies from one Task API without mixing their data: tenant ids, resolvers, trust levels and tenant-scoped queries with @zudojs/tenancy.45 min
  3. 17PluginsExtend the Task API through a fixed interface without editing it: plugin lifecycle, dependencies, scoped context, rollback and diagnostics with @zudojs/plugins.45 min
  4. 18Adapters with @zudojs/adaptersPut a payment provider behind an adapter with @zudojs/adapters, then swap a fake for a real HTTP provider without touching checkout.55 min

Course checkpoint

Prove you can move on. The checkpoint picks 20 questions at random from every lesson in this course. Get 16 right to pass. Your result is saved in this browser only.