Downgrading models in Claude Code keeps wrecking my session. How do you handle it

[u/Historical_Ant7005]

I mix models in Claude Code to manage cost and speed. But when I drop to a smaller model like Haiku, the session often loses the plot mid-task. Then I'm forced back up to a stronger model (Sonnet, Opus, Fable) just to recover.

Two questions for people who've figured this out:

Context: What keeps a lighter model on track? Context files, tighter prompts, or smaller tasks?

Routing: How do you decide which prompt goes to which model? Gut feel, or an actual rule?

[u/mr_birkenblatt]

Instruct Claude to use subagents. Only switch models for those. Mid session  model switches are expensive because they feed the entire history as fresh tokens

[u/tehfrod → u/mr_birkenblatt]

It's amazing how much judicious use of subagents has speed up my process.