Devin is genuinely impressive in demos and for well-scoped tasks. It can take a GitHub issue and ship a PR, which is wild. But it's not replacing your engineering team anytime soon — it struggles with ambiguous requirements, and the cost adds up fast on complex projects. Think of it as a very capable junior developer that never sleeps.
Best for teams with clear, well-documented tasks that need to ship faster. Not great for greenfield projects where the requirements are still fuzzy.