Senior Backend Software Engineer, Observability & Evals Platform (LangSmith)

What you will do:

• Design, develop, and maintain backend services and APIs to support LangSmith's tracing, monitoring, and evaluation workflows.
• Collaborate on architectural decisions to ensure systems are performant and maintainable.
• Optimize storage and query performance for high-volume observability and evaluation data.
• Ensure system reliability through strong testing, monitoring, and alerting practices.
• Troubleshoot and resolve production issues, performing root-cause analysis and implementing long-term fixes.
• Create and maintain technical documentation, including system design and API references.
• Work closely with full-stack engineers, product managers, and product designers on rolling out new features.

How to be successful:

• 5+ years of professional experience in backend engineering
• Proficiency in one or more backend languages/frameworks, ideally Python or Go
• Strong understanding of API design and building reliable data services.
• Experience with high-throughput or mission-critical systems.
• Demonstrated ability to optimize backend services for performance and reliability.
• Experience with database systems (Postgres, Redis, Clickhouse), and cloud platforms (AWS, GCP, Azure)
• Strong communication skills, with the ability to collaborate cross-functionally
• Customer centricity and ownership mentality

Compensation & Benefits

Annual salary range: $175,000-$225,000. Competitive compensation includes base salary, meaningful equity, health/dental coverage, flexible vacation, 401(k), and life insurance.