The 10-to-1 rule: replace ten mid-level devs with one senior

Ten mid-level engineers cost roughly $1.6 million a year. Together, they produce 30 to 40 merged PRs per week, after meetings, sick days, vacation, hiring and the inevitable two who quietly look elsewhere. A senior vibe coder costs $300K to $450K and alone produces 25 to 40 merged PRs per week. That's the rule

Where the leverage comes from

No overhead to coordination. No stand-ups. No sprint planning theater. No waiting for the other team's branch. The senior types into Cursor or briefs Claude Code and the work happens. The savings on coordination alone is half the week of a mid-level engineer

The output is not just lines

A mid-level shipping a feature ships the feature. A senior shipping a feature ships the feature, the migration, the tests, the rollback plan, the metric and the post-mortem template. The 10-to-1 is not 10 times the lines. It is 10 times the surface area handled per merge

The awkward conversation

If your team of ten can be replaced by one, you have a difficult quarter ahead of you. The math is public. Investors read it. The companies that figure it out first get the runway extension. Those that don't, get the down round

Where the rule breaks

It doesn't work everywhere. If your product is a regulated industry with five compliance reviewers per release, then engineering is not the bottleneck. If your codebase is a 15-year-old monolith with no test coverage, one senior cannot save it. The rule applies where the bottleneck is shipping, which is usually the case, but not always

The middle path

You don't have to fire everyone. You need to stop hiring more mids and start hiring seniors who treat AI as a collaborator. The shape of the team changes from a pyramid to a small constellation. Smaller, sharper, faster. The companies resisting this are the ones still trying to hire their way out of a productivity problem

Hire the one →