GitHub Copilot After 6 Months: What Nobody Tells You

The Setup

Our engineering team of 8 started using GitHub Copilot Business 6 months ago. We've tracked time savings, code quality, and team satisfaction. Here's the honest assessment — including the parts that don't make it into GitHub's marketing materials.

The Gains Are Real

The headline metric: our team estimates 25-35% time savings on implementation tasks — writing boilerplate, generating tests, and completing repetitive patterns. Engineers universally report that Copilot is particularly valuable for tasks they find tedious: RegEx writing, SQL queries, and TypeScript interface definitions.

Copilot Chat (the conversational interface inside VS Code) has become the default debugging tool. "What's wrong with this code?" and "How do I refactor this to use X pattern?" are faster than Stack Overflow for most common problems.

The Hidden Costs

Confident Wrong Answers

Copilot's biggest risk isn't that it writes wrong code — it's that it writes wrong code confidently. Junior engineers who accept suggestions without careful review are the most at risk. We've seen bugs introduced by plausible-looking Copilot suggestions that were subtly incorrect in ways that only surfaced in edge cases. Code review discipline matters more with AI assistance, not less.

Security Awareness

Several security researchers have demonstrated that Copilot can suggest insecure patterns — SQL injection vulnerabilities, hardcoded credentials in example code, and insecure cryptographic implementations. Your security review process needs to explicitly account for AI-generated code.

The Dependency Risk

After 6 months, engineers on the team report reduced comfort with the types of tasks they previously handled manually. This is worth monitoring. AI assistance should amplify capability, not atrophy it. We now require engineers to disable Copilot for certain types of exercises as part of onboarding.

Copilot vs Cursor: After 6 Months

Three of our engineers switched to Cursor after month three. Their assessment: the codebase-aware AI and Composer feature are substantially more powerful for complex refactors and multi-file changes. The remaining five stayed on Copilot — primarily because of JetBrains support (two use IntelliJ) and familiarity.

Our Recommendation

GitHub Copilot Business is worth the investment for engineering teams. The productivity gains are real and measurable. Build your adoption plan around: clear guidelines on review expectations, security scanning as a backstop, and regular exercises that keep engineers sharp on core skills. The tool is good. The discipline around using it well is what separates teams that benefit from teams that accumulate technical debt.