Hi HN,

For those running LLMs in real production environments (especially agentic or tool-using systems): what’s actually worked for you to prevent confident but incorrect outputs?

Prompt engineering and basic filters help, but we’ve still seen cases where responses look fluent, structured, and reasonable — yet violate business rules, domain boundaries, or downstream assumptions.

I’m curious:

Do you rely on strict schemas or typed outputs?

Secondary validation models or rule engines?

Human-in-the-loop for certain classes of actions?

Hard constraints before execution (e.g., allow/deny lists)?

What approaches failed for you, and what held up under scale and real user behavior?

Interested in practical lessons and post-mortems rather than theory.