I run parallel coding agents on my own projects daily. The code they produce is fine. What worries me is the "just ship it" energy where nobody on the team deeply understands what got built. That's not an AI problem, it's been a problem with outsourced codebases forever. AI just makes it faster to accumulate code nobody fully groks.
Cloudflare probably has the engineering depth to maintain this regardless of how it was built. A lot of other teams don't.