Opus 5.5 impresses with reasoning but forgets everything between sessions, user complains
Character_Cream_1612 · reddit · 2026-09-26
A Reddit user reports that Opus 5.5 is the smartest coding model they've used—reasoning is excellent and it often produces working code on the first try—but its lack of memory persistence is a major pain point. Every session starts from zero: they must re-explain their stack, project structure, and prior decisions, and one session that mapped out half a backend implementation was forgotten the next day. Mid-session drift kicks in after 30-40 messages, and custom instructions, system prompts, project files, and markdown docs haven't fixed the problem.
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