Opus 5.5 builds a full-stack app in four hours, one developer says

Eco @IndependentEcoOriginally posted 2026.09.26

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Opus 5.5 feels like cheating. I have been running a single session of Opus 5.5 high for the last 4 hours on my $20 plan. I gave it instructions not to use subagents to save usage. It was able to build a full stack application that feels surprisingly production ready. I’m going to have GPT-6 Sol check its work and I will let you know if it finds anything. Opus 5.5 is a cheat code at this point.