FullStack Engineer, AI Observability & Evals Platform (LangSmith)
LangChain
FullStack Engineer, AI Observability & Evals Platform (LangSmith) at LangChain is a full time role based in United States. The listing states pay of $145k–$180k. It was published on 15 August 2025 and was open at last check.
| Role | FullStack Engineer, AI Observability & Evals Platform (LangSmith) |
|---|---|
| Company | LangChain |
| Location | United States |
| Employment type | Full Time |
| Pay (as listed) | $145k–$180k |
| Published | 15 August 2025 |
| Status | Open at last check |
About Us
At LangChain, our mission is to make intelligent agents ubiquitous. We build the foundation for agent engineering in the real world, helping developers move from prototypes to production-ready AI agents that teams can rely on. We began as widely adopted open-source tools and have grown to also offer a platform for building, evaluating, deploying, and operating agents at scale.
With $125M raised at Series B from IVP, Sequoia, Benchmark, CapitalG, and Sapphire Ventures, we’re at a stage where we’re continuing to develop new products, growth is accelerating, and all team members have meaningful impact on what we build and how we work together. LangChain is a place where your contributions can shape how this technology shows up in the real world.
Today, our platform includes LangSmith (Observability, Evaluation, Deployment, Fleet, and Sandboxes), our open source frameworks (LangChain, LangGraph, and Deep Agents), and the newly launched LangSmith Engine for autonomous agent improvement. We have 100M+ monthly open source downloads, 6,000+ active LangSmith customers, and 5 of the Fortune 10 use LangSmith in production (+ 35% of the Fortune 500 overall), including teams at Klarna, Clay, Coinbase, Workday, Lyft, Cloudflare, Harvey, Rippling, Vanta, LinkedIn, Monday.com, Nvidia, and Bridgewater.
About the role
We're looking for a Fullstack Engineer to work on LangSmith, our commercial AI observability and evals platform product. In this role, you'll have the opportunity to build new features and functionality for the platform while working close enterprise customers, developer end-users and internal stakeholders.
What you will do
- Develop and implement key product features working across our entire Go, Python, and Typescript stack
- Collaborate closely with product and design teams to iterate on new features and enhance the product roadmap
- Drive aggressive project timelines while ensuring high engineering standards are being met by writing clean, maintainable, and well-tested code
How to be successful in this role
- 2+ years of experience in software engineering working on complex platform products
- Fullstack engineering experience with Go or Python on the backend and React + Typescript on the frontend
- Solid understanding of database systems, particularly Postgres and Redis
- Experience designing and scaling APIs, preferably in high-performance, data-intensive applications
- Strong ownership and a “get stuff done” mindset - comfortable shipping fast and iterating based on user feedback
- Strong communicator with the ability to collaborate closely with various internal stakeholders and engage directly with our top-tier customers
- Bonus: Experience with AI/LLM-powered applications, developer tools, or observability platforms
Compensation
Annual salary range: $145,000-180,000 USD
Compensation Philosophy:
We offer competitive compensation that includes base salary, variable compensation for relevant roles, meaningful equity, benefits, and perks. Actual compensation and offerings will vary based on role, level, and location. Team members in the EU, UK, and APAC receive locally competitive benefits aligned with regional norms and regulations.
Benefits
Benefits include medical, dental, and vision coverage, flexible vacation, a 401(k) plan, meals on in-office days in the US and more.
Create your free OnJob profile to apply — we'll take you to LangChain's application after sign-up. · Posted 15 Aug 2025.
FullStack Engineer, AI Observability & Evals Platform (LangSmith) at LangChain — questions answered
What does the FullStack Engineer, AI Observability & Evals Platform (LangSmith) role at LangChain pay?
The FullStack Engineer, AI Observability & Evals Platform (LangSmith) at LangChain listing states pay of $145k–$180k for the United States position. That figure is taken directly from the employer's own posting as published, not estimated or averaged from other roles.
Where is the FullStack Engineer, AI Observability & Evals Platform (LangSmith) role at LangChain based?
LangChain lists this FullStack Engineer, AI Observability & Evals Platform (LangSmith) role in United States, advertised as full time work at that location. Larger employers sometimes cover several sites under one city name, so confirm the exact office with LangChain before you apply.
Is the FullStack Engineer, AI Observability & Evals Platform (LangSmith) role at LangChain still open?
The FullStack Engineer, AI Observability & Evals Platform (LangSmith) posting at LangChain was open at OnJob's last check of the employer's careers page, having been published on 15 August 2025. OnJob re-checks source listings on each build and marks a role closed once it disappears, but listings can close without notice, so the employer's own page is the final word.
How do you apply for the FullStack Engineer, AI Observability & Evals Platform (LangSmith) role at LangChain?
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