LangSmith, a platform for LLM application development, monitoring, and testing, is now generally available following a successful beta phase that began in July 2023. The platform, which has garnered over 80,000 signups and is used by leading companies like Rakuten and Moody's, supports every stage of the LLM application lifecycle, from prototyping to production, offering features such as debugging, test-driven development, comparison views, and beta testing. It allows developers to rapidly iterate and evaluate different prompts and models through a user-friendly playground environment, and supports the collection of user feedback and annotation of traces to identify performance issues. LangSmith also facilitates monitoring and A/B testing in production, ensuring applications deliver desirable results at scale. The company recently raised $25 million in a Series A round led by Sequoia Capital to further develop the platform and expand its team. Future enhancements aim to include regression testing, improved filtering, and enterprise features for larger customers, maintaining its innovative edge in the fast-evolving LLM industry.