> Markdown version of [/jobs/ext/3368360-senior-backend-software-engineer-ai-observability-evals-platform-langsmith](https://www.wearedevelopers.com/jobs/ext/3368360-senior-backend-software-engineer-ai-observability-evals-platform-langsmith). Every page supports `.md` or `Accept: text/markdown`. Links point to the HTML versions so they work for humans too. Agent guide: [/agents.md](https://www.wearedevelopers.com/agents.md).

---

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

- **Company:** Langchain, Inc
- **Location:** Cambridge, MA, United States
- **Experience:** Expert
- **Salary:** $180,000.0 - $240,000.0
- **Contract:** Permanent contract
- **Skills:** Query Performance, Application Programming Interfaces (APIs), Artificial Intelligence, Amazon Web Services, Microsoft Azure, Databases, Data as a Services, Software Debugging, Python (Programming Language), PostgreSQL, Performance Tuning, Redis, Google Cloud, Reliability of Systems, Backend, Front End Software Development, Vertica, Api Design
- **Published:** September 11, 2026
- **Apply:** https://www.indeed.com/viewjob?jk=84f3a18a51811a21

## About the Role

* 4+ years of professional experience in backend engineering working on highly complex products
 * Proficiency in one or more backend languages/frameworks, ideally Python and/or Go
 * Strong understanding of API design and building reliable data services.
 * Experience with high-throughput, 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) would be a bonus.
 * Strong communication skills, with the ability to collaborate cross-functionally.
 * Customer centricity and ownership mentality

## Description

We are looking for a Senior Backend Engineer to join our growing engineering team in Boston. In this role you will be building the backend systems that power LangSmith, LangChain's observability and evals platform. You will work on the core services that allow our customer's developer teams to monitor and evaluate their AI applications at scale. While the focus is on backend feature development, familiarity with fullstack or frontend engineering, performance tuning, and debugging production issues would be valuable., * 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.