The demo-production gap: Most LangChain tutorials show 20-line demos that break in production. Real production requires: error handling for every chain step, timeout management, cost tracking per chain execution, structured logging for debugging, and graceful degradation when components fail.
Evaluation and testing: I build automated evaluation suites that test chain output quality against golden datasets. Every deployment includes regression tests that catch quality degradation before it reaches users. LangSmith integration provides trace-level debugging for complex chains.
Performance optimization: LangChain adds latency through abstraction layers. I optimize by parallelizing independent chain steps, caching intermediate results, using async execution where possible, and eliminating unnecessary abstraction layers. Typical latency reduction: 40-60% compared to naive implementation.
Version management: Prompt templates, chain configurations, and tool definitions are version-controlled separately from code. This enables A/B testing of different chain configurations and instant rollback if a new prompt degrades quality.