From line completion to whole features — AI now writes most boilerplate, scaffolds tests, and increasingly tackles real product work. The largest, fastest-growing slice of developer AI usage.
← Back to AI LandscapeGhost-text suggestions as you type. Fast (<200ms), small models (Supermaven, Codeium, Copilot Tab).
"Add a function that…" — generates a function or refactors a file. Cursor Chat, Copilot Chat, JetBrains AI.
"Build the checkout flow." Reads files, edits multiple, runs tests, iterates. Claude Code, Cursor Composer, Devin.
Better than diving in. Write a short spec — the model will follow it.
// Bad "add caching" // Good "Add an LRU cache to ProductService.getById: - Max 1000 entries - 5-minute TTL - Cache key: `product:${id}` - Use the existing Caffeine library; see CacheConfig.java - Add a unit test that verifies eviction after 1001 inserts"
Point the agent at an example. "Build a UserController like ProductController in src/api/products/" gives it the conventions, naming, and test style without you spelling it out.
For agents: small task → run tests → review diff → fix or accept. Don't ask for "the whole feature" in one go — break it into steps you can verify in minutes.
Tests act as a contract — they pin down intent better than prose, and the agent gets a fast feedback signal.
Calls to functions that don't exist. Linters, types, and tests catch most.
Code that compiles, looks right, but does the wrong thing. Read every diff.
Verbatim reproduction of GPL code. Use Copilot's filter / similar guards.
Junior devs miss out on muscle memory. Mix AI work with hand-written code.
It's easy to generate too much code. Prune ruthlessly; don't merge unused.
SQL injection, weak crypto, leaked secrets. SAST + human review still required.