I have a wide range of Claude Code based setups, including one with an integrated issue tracker and parallel swarms. And for anything really serious? Opus 4.5

I have a wide range of Claude Code based setups, including one with an integrated issue tracker and parallel swarms. And for anything really serious? Opus 4.5 struggles to maintain a large-scale, clean architecture. And the resulting software is often really buggy. Conclusion: if you want quality in anything big in February 2026, you still need to read the code.