Copilot vs Cursor: I Switched. Here's What Broke.

The hottest take I have after 12 months: GitHub Copilot slowed down my junior engineer and I didn't notice for six months.

Not a bug. A feature. I'll explain.

The Problem With Copilot

2023. Reconciliation service. $2B daily transaction volume. One junior engineer who was genuinely sharp. We gave everyone Copilot Business and moved on.

Six months later his PRs looked polished but his standups were thin. He couldn't explain his own code. Copilot had been finishing his sentences before he learned to form the thought. That's not acceleration. That's dependency.

Copilot is autocomplete that got too confident. It's great at boilerplate. It's dangerous when someone doesn't know enough to reject its suggestions.

What Cursor Actually Does Differently

I switched to Cursor in January 2024. The difference isn't the model. It's the interaction pattern.

Cursor forces you to articulate what you want. You write a prompt. You read the diff. You approve or reject. That loop builds understanding. Copilot skips the loop entirely and just inserts code while you blink.

On a recent payments SDK refactor, Cursor with Claude 3.5 Sonnet caught a race condition in our retry logic that two senior engineers missed in review. Not because the model is magic. Because I had to describe the system well enough to get useful output, and that description itself exposed the bug.

The Actual Verdict

Copilot wins for senior engineers who already know what bad looks like. Fast tab completion, stays out of your way, integrates everywhere.

Cursor wins for complex, multi-file reasoning and anyone who wants to think harder, not less.

Don't give Copilot to juniors. I've seen this kill production code quality at two companies now. Both times nobody noticed until it was expensive.