Migration Order, Backward Compatibility, and Release Sequence Database deployment is where rollback gets difficult. Prefer expand-migrate-contract changes so the old application and the new application can coexist during rollout and rollback windows.
Expand schema → Migrate data → Deploy code → Observe → Contract later
Release ordering • 1. Validate production configuration and backups/recovery posture.
• 2. Run prisma migrate deploy as a one-off migration job.
• 3. Deploy the API SHA image and wait for readiness.
• 4. Deploy/promote the web application.
• 5. Run smoke tests and watch telemetry.
Avoid fragile migrations • Do not rename/drop a column in the same instant the old API might still use it.
• Add new structures first, deploy compatible code, migrate data, then remove obsolete structures in a later release.
• A code rollback cannot magically reverse destructive database changes. # Migration release step pnpm --filter api exec prisma migrate deploy
# Only after success: # - promote API image # - promote web deployment
Rollback-friendly deployment starts with rollback-friendly schema changes.
Source basis: Prisma deployment workflow from earlier phases plus production-safe expand/migrate/contract release practice.
Prisma improves developer ergonomics, but migrations and generated queries still change a real relational database. You should be able to inspect both sides.
Restate the goal of “Migration Order Backward Compatibility and Release Sequence” as one observable behavior. Write the success signal before touching code.
Trace the boundary map: domain intent → Prisma Client → generated SQL → PostgreSQL → mapped result. 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: Staging and production deployment runbooks with release identity, environment matrix, smoke tests, and rollback procedure.. 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.
const tasks = await prisma.task.findMany({
where: { workspaceId },
orderBy: [{ createdAt: "desc" }, { id: "desc" }],
take: 20,
});Do 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.
Verify connection string, host, port, SSL/pooler mode, network reachability, and which environment file the process loaded.
Read the generated SQL before applying it and compare the change against existing production-shaped data.
Without copying the final source, create a second small scenario that applies “Migration Order Backward Compatibility and Release Sequence” to a different TaskFlow resource or input. Write the acceptance criteria first, implement it, and provide the evidence that each criterion is satisfied.
Create separate staging/production environment matrices before entering any dashboard values.
Use the smallest change that demonstrates this lesson. Stop after it works and capture evidence.Code deploy occurs before required migration or vice versa without compatibility plan
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.