TaskFlow Production System Blueprint The product we will grow throughout the course - scope, domain model, vertical slices, security boundaries and final production architecture.
Book 2 · Capstone system blueprint Course baseline: September 17, 2026 · Windows-first · Project-driven · Production-oriented
Contents 1. Why TaskFlow 7. Security model preview
Phase 00 | Page 2 of 7
Why TaskFlow instead of a giant enterprise domain on day one? The project must be complex enough to teach production engineering, but simple enough that architecture remains visible. TaskFlow starts with a personal Todo feature, then grows into a workspace-based collaboration system. Each expansion introduces one new class of engineering problem.
Identity Organizations Signup, login, logout, session refresh, Workspaces, membership, invitations, roles protected routes and profile basics. and ownership.
Projects Tasks Project lifecycle, status, metadata and Create, assign, prioritize, filter, paginate, membership-aware access. complete and archive.
Collaboration Operations Comments, activity history, notifications and Audit logs, testing, structured logs, health carefully selected realtime. checks, CI/CD and deployment.
User Authenticated identity represented by Supabase Identity must be trusted from a verified token, Auth plus application profile data. not a browser-supplied userId.
Workspace Tenant/team boundary containing projects and Introduces multi-tenant authorization. members.
Membership Relationship between a user and workspace with Introduces many-to-many modeling and RBAC. a role.
Project Container for collaborative work. Introduces parent-child resource ownership.
Phase 00 | Page 3 of 7
Task Unit of work with status, priority and Exercises CRUD, validation, filtering and assignment. optimistic updates.
Activity Immutable description of important domain Introduces audit/history thinking. events.
Figure 1 - Domain relationship preview - This is a conceptual map, not yet a final database schema.
We do not create the final schema on day one. The product grows in vertical slices so the learner can see cause and effect.
Phase 00 | Page 4 of 7
Figure 2 - Vertical-slice growth - Each stage should produce a usable, testable application state.
GET /health
GET /todos
POST /todos
PATCH /todos/:id
DELETE /todos/:id# Later
GET /workspaces
POST /workspaces
GET /workspaces/:workspaceId/projects
POST /projects/:projectId/tasks
PATCH /tasks/:taskId
POST /tasks/:taskId/commentsWe start with resource-oriented REST endpoints because they keep the HTTP boundary visible. More advanced patterns are introduced only if a concrete problem appears.
Phase 00 | Page 5 of 7
Figure 3 - Trusted identity path - Never use a raw browser-supplied user id as proof of identity.
Figure 4 - Future application navigation - A practical shell that will exercise layouts, routing, forms, tables and responsive UI.
Phase 00 | Page 6 of 7
Microservices, Kubernetes, Kafka, CQRS, event sourcing, GraphQL, distributed caches and complex domain-driven architecture are not prerequisites for learning to build a high-quality production application. They can be valuable in the right system, but adding them before the application has demonstrated the problem they solve makes the architecture harder to understand.
The course teaches patterns through TaskFlow, but every architecture explanation asks how the same responsibility would appear in a larger business system.
Phase 00 | Page 7 of 7
TaskFlow Blueprint matters because it changes a real boundary in TaskFlow. The goal is to understand the inputs, owner, observable output, and failure modes before adding more abstraction.
Restate the goal of “TaskFlow Blueprint” as one observable behavior. Write the success signal before touching code.
Trace the boundary map: User intent → UI boundary → API contract → business rule → persistence → observable 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: A one-page architecture map plus an ADR-style note describing the responsibilities of Next.js, NestJS, Prisma, PostgreSQL/Supabase, and supporting infrastructure.. 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.
Input -> owner -> transformation -> observable output -> failure evidenceDo 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.
Return to the nearest observable boundary: input, network, process log, database, or rendered UI. Compare actual evidence with the predicted path.
Change one variable at a time and reproduce the original failure after the fix; otherwise you have correlation, not diagnosis.
Without copying the final source, create a second small scenario that applies “TaskFlow Blueprint” to a different TaskFlow resource or input. Write the acceptance criteria first, implement it, and provide the evidence that each criterion is satisfied.
Label every arrow with what crosses it: props, HTTP JSON, verified identity, Prisma calls, SQL results.
Use the smallest change that demonstrates this lesson. Stop after it works and capture evidence.Letting controllers call the database directly everywhere
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.