How to keep Claude Code effective as context fills up

Claude Code sessions get less effective as they get longer. The model has to attend to everything in context — and as the window fills with old code, old errors, and old attempts, the signal-to-noise ratio drops. Signs of context degradation Repetition : Claude suggests something you already tried, or confirms something already confirmed Drift : Output stops following your established patterns and reverts to generic style Hallucination uptick : Wrong function names, wrong file paths, invented APIs When these appear, compact or start a new session. Don't keep pushing. Front-load context instead of accumulating it The most common mistake in long sessions is letting context accumulate passively — pasting errors, pasting file contents, asking follow-ups. Each exchange adds tokens, and after an hour the model is carrying all of it. Better approach: at the start of each session, give Claude a precise summary of what matters. What files are in scope. What patterns the codebase uses. What you'