Senior Fullstack Software Engineer, AI Observability & Evals Platform (NY)
At a glance
Senior Full-stack Engineering role at LangChain. San Francisco, CA · full-time · $175,000–$240,000 base.
techroles summary, based on the employer's posting.
What you'll do
- Set the technical direction and build major LangSmith features across its Go, Python and TypeScript stack
- Shape new features with product and design partners through ongoing iteration
- Coach less experienced engineers and keep projects moving on demanding timelines without lowering engineering standards
- Set an example by producing code that is maintainable, clear and thoroughly tested
What you bring
- At least five years in software engineering, building complex platform products
- Full-stack skills spanning Go or Python services and React with TypeScript interfaces
- A strong grounding in databases such as Postgres and Redis, plus experience designing and scaling APIs
- Clear communication, ownership and the ability to work with internal partners and speak directly with customers
Who this fits
This senior role suits an engineer ready to guide technical decisions, mentor teammates and deliver platform features. The position is listed as onsite in the United States.
From the employer
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 Senior Fullstack Engineer for our commercial product LangSmith, an observability and evals platform. In this role, you'll have the opportunity to shape the technical direction of our platform while working closely with enterprise customers, developer end-users and internal stakeholders.
What You Will Do:
Lead the technical architecture and implementation of key product features for LangSmith, working across our entire Go, Python, and Typescript stack.
Collaborate closely with product and design teams to iterate on new features.
Mentor and guide more junior members of the team. Drive aggressive project timelines while ensuring high engineering standards are being met.
Lead by example in writing clean, maintainable, and well-tested code
What You Bring:
5+ 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.
Strong understanding of database systems, particularly Postgres and Redis
Experience designing and scaling APIs, preferably in a high-performance, data-intensive application
A “get stuff done” attitude - 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
Strong ownership mindset
Bonus: Experience with AI/LLM-powered applications, developer tools, or observability platforms
Annual salary range: $175,000-$240,000 USD
Compensation Philosophy:
We offer competitive compensation that includes base salary, variable compensation for relevant roles, meaningful equity, benefits, and perks.
We are hiring for this role across a range of scope, and the compensation band reflects that. Your offer depends on what we learn about your impact, craft, leadership, and communication during the interview process. We will tell you early where you’re tracking and talk comp with you before offer stage. 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.
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