Mission Rebuild the capability of Phase 32 without following the exact code line-by-line. The goal is transfer: can you use the ideas when the variable names, UI, or route shape changes?
Required outcome Containerize the production API/web artifacts reproducibly with secure runtime configuration, small images, health checks, networking, and graceful shutdown.
Required artifact Dockerfiles and compose/dev verification that build and run TaskFlow services from clean inputs.
Constraints • Start from the previous phase checkpoint or a fresh branch. • Use the course architecture boundaries, but do not copy the reference implementation until after your first attempt. • Keep changes scoped to the capability. • Preserve validation, authorization, error handling, and observability expectations already earned in earlier phases. • Record any design decision where more than one implementation is reasonable.
Acceptance criteria • Can explain image vs container. • Can build multi-stage image. • Can inject secrets at runtime. • Can diagnose ports/network/health failures.
Independent build sequence 1. Write a .dockerignore first so local node_modules, Git history, secrets, and build output do not enter context. 2. Create a multi-stage API Dockerfile separating dependencies/build/runtime artifacts. 3. Build with frozen lockfile and inspect image layers/size. 4. Run the container with runtime env vars and map the service port explicitly. 5. Add healthcheck/readiness behavior and test startup plus graceful stop. 6. Create a small compose setup only for local integration needs and explain what remains externally managed.
Self-review Compare your implementation to the reference only after the acceptance criteria pass. Differences are not automatically mistakes. For each difference, ask: does it preserve the same contract, security boundary, correctness, maintainability, and operational behavior? Keep the alternative when you can justify it with evidence.
Stretch challenge Change one assumption: more users, a second tenant, a slow network, an expired session, a concurrent mutation, a deployment restart, or a failed dependency. Predict whether your design still behaves correctly. If not, document the next architectural improvement rather than adding complexity blindly.
Phase exit Run the relevant checks, inspect Git diff, and write a three-sentence summary: what the system can do now, which boundary owns the new responsibility, and which failure you now know how to diagnose. Only then mark the phase complete.
Containers package a process and its runtime assumptions. The lesson is not memorizing Docker commands; it is making those assumptions repeatable and observable.
Restate the goal of “Phase Synthesis & Independent Challenge” as one observable behavior. Write the success signal before touching code.
Trace the boundary map: source + lockfile → build context → image layers → container process → health signal. Mark the one boundary this lesson changes.
Inspect the current repository state and record the exact files, route, table, or runtime involved. Avoid creating an abstraction before you can name the existing owner.
Implement the smallest vertical slice. Add one coherent change, run the narrowest verification command, and read the output before continuing.
Connect the slice to TaskFlow’s phase artifact: Dockerfiles and compose/dev verification that build and run TaskFlow services from clean inputs.. Verify behavior from the outside as a user or API client would.
Create one controlled failure that is safe to reproduce. Predict the symptom first, capture evidence, locate the earliest broken boundary, then fix only that cause.
Close the reference and rebuild or explain the core change from memory. Record what you would monitor or test before trusting the same change in production.
FROM node:24-alpine AS build
WORKDIR /app
RUN corepack enable
COPY package.json pnpm-lock.yaml pnpm-workspace.yaml ./
COPY apps/api/package.json apps/api/package.json
RUN pnpm install --frozen-lockfile
COPY . .
RUN pnpm --filter api buildDo not copy this as a finished answer. Predict what each boundary does, type the smallest useful slice, run it, then compare the result with your prediction.
Inspect container logs and PID 1 command; confirm the process stays in foreground and required config exists.
Check bind address, exposed/published ports, network namespace, and health endpoint.
Without copying the final source, create a second small scenario that applies “Phase Synthesis & Independent Challenge” to a different TaskFlow resource or input. Write the acceptance criteria first, implement it, and provide the evidence that each criterion is satisfied.
Build with frozen lockfile and inspect image layers/size.
Use the smallest change that demonstrates this lesson. Stop after it works and capture evidence.Huge build context invalidating caches
Predict the symptom before causing the failure. Then locate the earliest boundary where reality diverges from expectation.Why does this responsibility live here, what input does it trust, what output proves success, and what would go wrong if another layer owned it?
If your explanation is vague, repeat the boundary trace before moving on.Close the reference. Reproduce the core idea from memory or explain the exact request/data flow aloud. Then check your diff or notes for accidental shortcuts that bypass validation, authorization, error handling, or verification earned in earlier phases.