09 — Going further

In this chapter:

• A menu of next steps to take the Todo app beyond the workshop
• Each item is a short prompt you can drop into Copilot CLI
• Pick two or three that interest you — don't try to do them all

The goal isn't to finish every idea below. It's to leave the workshop with a clear sense of what's possible and the muscle memory to pursue any of it on your own.

1. Real authentication

The hardcoded-users dropdown was a teaching device. In a real app, you want authenticated users.

Easiest path: OAuth 2.0 with GitHub, Google, or Microsoft as identity provider. Spring Security has a one-dependency integration for this (spring-boot-starter-oauth2-client).

Prompt:

Replace the hardcoded user dropdown with OAuth 2.0 login via GitHub.

- Add spring-boot-starter-oauth2-client and configure a client-registration
  for GitHub that reads client-id and client-secret from env vars.
- Protect /api/** so only authenticated users can access it.
- The current "user" attached to a todo should be the authenticated user's
  GitHub login; remove the dropdown.
- Keep existing per-user filtering.

Follow Dr JSkill's security conventions. Walk me through creating the GitHub OAuth app.

See references/SECURITY.md for the full treatment.

2. Observability with Prometheus + Grafana

Chapter 7 enabled Actuator metrics. Now scrape them.

Prompt:

Add a prometheus + grafana service to compose.yaml (dev only).

- Prometheus scrapes the app's /actuator/prometheus endpoint every 15s.
- Grafana is pre-provisioned with a Prometheus datasource and a basic
  Spring Boot dashboard (JVM, HTTP request rates/latency, DB connection pool).
- Document the URLs in the README.

You now have a real observability stack on your laptop, for free.

3. Keyset (seek) pagination

Once you have more than a few hundred todos, offset pagination (LIMIT 20 OFFSET 10000) gets slow. Keyset pagination scales to any table size.

Prompt:

Switch the GET /api/todos endpoint from Pageable-based pagination to keyset
pagination using the "id" column. Accept an optional "after" query parameter
(the last seen id) plus a "limit" parameter (default 20, max 100).

Update the front-end to use infinite scroll based on the "after" cursor
rather than page numbers.

Follow Dr JSkill's database conventions.

4. Try a different front-end

Dr JSkill supports Vue, React, Angular, and Vanilla JS. Rebuild the same Todo app with a different one to compare.

In a fresh directory:

mkdir ~/workshop-react && cd ~/workshop-react
copilot

Then:

Use Dr JSkill to create a new Todo List application identical to what we
built in ~/workshop, but using React instead of Vue. Keep the same features:
add/edit/remove todos, hardcoded users (julien/alice/bob), per-user filter,
Bootstrap styling, toasts, loading spinners.

Side-by-side, you'll feel the differences between the frameworks — and see that the Spring Boot backend is almost identical.

See references/REACT.md, references/ANGULAR.md, references/VANILLA-JS.md.

5. Replay on another domain

The real test of an agent skill is whether it works on a completely different problem. Pick one and start over:

• A Bookmark manager (URL, title, tags, "read" flag)
• A Recipe book (recipes with ingredients, step-by-step instructions)
• A Expense tracker (amount, category, date, user)
• A Inventory system (products with stock counts, simple movements)

Prompt (example):

Use Dr JSkill to create a Bookmark Manager.

- Entities: Bookmark (url, title, description, tags, read/unread).
- Tag filtering and full-text search on title+description.
- Vue + Bootstrap UI.
- PostgreSQL, no security.

Running the whole workshop on a second domain in under an hour is the real proof that you've internalized the workflow.

6. Turn the skill into yours

If Dr JSkill's conventions don't match yours exactly — maybe you prefer Gradle, or H2 for dev, or a different package layout — fork the skill and edit it.

The whole skill is Markdown files in ../references/ and ../SKILL.md. Change a few sentences, bump a version in ../versions.json, and the next project the agent generates will follow your conventions instead. No plugin system, no build step.

Prompt (from inside ~/.copilot/skills/dr-jskill):

I want to add a new reference file describing how the application should
integrate with our team's custom logging service. Draft references/ACME-LOG.md
with the usage pattern and add it to SKILL.md's reference list.

See the skill's own README for how to point Copilot CLI at your fork.

7. Teach the workshop

The single best way to cement what you learned: run this workshop for someone else. Pair with a colleague. Stream it. Talk at a meetup.

You'll find the rough edges faster than on your own, and you'll discover which prompts actually land — and which need rephrasing. If you find improvements, PRs to workshop/ are welcome.

Further reading

Checkpoint

You've reached the end of the workshop.

• You generated a Spring Boot + Vue app from a prompt
• You extended it with users, polished the UI, added tests, tuned performance, deployed it
• You know where to go for anything deeper

Appendices:

• A — Prompt cheat sheet
• B — Troubleshooting