Codex & Copilot Mastery
Inline completion done right. Test-driven habits, disciplined review, and the security hygiene your team needs before they auto-accept another suggestion.
Who this is for
Target audience
- Engineers who use Copilot or Codex daily for inline completion
- Teams that want consistent quality from AI-assisted code generation
- Organizations evaluating or expanding inline AI tool adoption
Prerequisites
- Working knowledge of at least one programming language
- Comfort with an IDE (VS Code, JetBrains, etc.)
- No prior Copilot/Codex experience required
What you'll learn
10 lessons, each built around the same structure: show, tell, do, break it, check. No lesson has more than 15 minutes of passive content before a hands-on moment.
- 1
What inline AI assistants are and aren't
Inline vs. chat vs. agent mode. Hallucinations in inline completion. The review reflex that prevents bad code from shipping.
- 2
Prompting by naming and commenting
Comment-driven prompting, docstring-driven prompting, naming as a hint, the micro-spec technique, anti-patterns.
- 3
First hour in Codex/Copilot
Project-level configuration (AGENTS.md, .github/copilot-instructions.md), language-specific nuances, workspace hygiene.
- 4
Test-driven work
Red/green/refactor with inline completion. Generating tests that actually test, property-based tests, tautological assertions.
- 5
Staged refactors
Multi-file refactor patterns, human-checkpointed edits, recovering from half-applied changes. Ends with a graded cross-file rename.
- 6
Integrations
Terminal integration, VCS commit messages and PR descriptions, issue tracker integration, cloud SDK awareness.
- 7
Debugging drift
When completions drift mid-file, when completions invent APIs, breaking the pattern with reset and retry.
- 8
Security and privacy
What data leaves your machine, enterprise vs. consumer plans, data retention settings, secrets and prompt injection.
- 9
Capstone: feature delivery
End-to-end feature delivery on a real repo using only Codex/Copilot. Graded on correctness, test quality, and code hygiene.
- 10
Going further
When to use chat-mode alongside inline, when agents beat inline, preview of Skills and subagents.
What you'll build
Every track includes graded hands-on labs on realistic codebases. No toy examples.
Broken-prompt lab
Six prompts that produce subtly wrong completions. Diagnose what's wrong, fix the prompt, and verify the output.
Cross-file rename capstone
Rename a core abstraction across 12 files using only inline completion. Graded on correctness and zero regressions.
End-to-end feature using only inline tools
Build a feature from scratch in a sample repo using Codex/Copilot. No chat, no agent mode — pure inline discipline.
Sample lesson preview
Lesson preview
Test-driven work: red/green/refactor with inline completion
- Write the test first, then let the completion fill in the implementation — and why order matters
- Generating tests that actually test: how to avoid tautological assertions that pass but prove nothing
- Property-based tests and fuzzing prompts: getting the model to think about edge cases
- Hands-on: build a small utility with 100% test coverage using only inline suggestions
Certified AI Engineer (Codex/Copilot)
Complete this track to earn your CAE badge. Certifications are earned through practical assessment — a written exam plus a hands-on practical — not just quiz scores. Exportable as Open Badges 2.0 and verifiable by URL.
Badges are valid for 18 months, renewable with a short refresh assessment.
Start your team's training
Per-seat annual plans start at $300/user. Enterprise pricing available for teams over 200.
Not sure where to start?
Take our free 3-minute AI maturity assessment and get a personalized recommendation for which tracks fit your team.