Plan Mode

What This Demonstrates

Copilot’s plan mode builds structured implementation plans, migration strategies, and execution-ready TODO lists — grounded in the actual codebase — before writing any code. It’s available in Copilot CLI and in agent mode across editors.

Prerequisites

• VS Code with Copilot Chat open
• Repository loaded (Codespaces or local clone)

Prompts

Prompt A — Feature Planning

Create an implementation plan for adding a `wishlist-service` to this monorepo.
Keep it consistent with existing patterns in `services/*` (Express + TypeScript),
include API endpoints, database schema ideas, events, tests, Docker, Helm, and CI
updates. Output phased steps with clear acceptance criteria.

What to look for:

• Phased approach matching existing services (controllers → services → repositories)
• Database schema following Prisma conventions
• Events for inter-service communication (e.g., wishlist.item.added)
• Helm chart and CI workflow updates

Prompt B — Migration Planning

Build a phased plan to introduce API gateway rate limiting and request tracing
across all backend services. Include risk areas, rollout strategy, and rollback
steps.

What to look for:

• Per-service impact analysis
• Rollout phases (dev → staging → production)
• Rollback procedures tied to Helm and Kubernetes

Prompt C — Execution-Ready Plan

Turn the wishlist plan into an actionable TODO list with dependencies and the
first 3 tasks I should implement now in this repo.

What to look for:

• Dependency graph between tasks
• Specific file paths and commands
• Clear “done” criteria for each task

Follow-Up Prompts

• “Estimate complexity for each task using T-shirt sizes.”
• “Which of these tasks could be parallelized across two developers?”
• “Generate the Prisma schema for the wishlist-service database.”