Founding Engineer, Platform & Infra

About Litmus

AI agents are starting to do real work across the economy, and the companies deploying them have no reliable way to know whether they can trust them. Litmus is building the system that lets every enterprise measure how its agents perform, understand why they fail, and make them better, starting with evaluation and building toward agents that improve on their own.

Litmus was founded in August 2026 by Sidharth Srinivasan, who built and led AI evaluation at Box after Box's CEO recruited him out of Stanford CS. We've raised $5M from Pear, BoxGroup, Workbench, and Emergence, alongside the CEO of Box, the co-founder of Dropbox, and senior executives from OpenAI, Anthropic, and Google.

The role

Build the infrastructure that simulates the real world for AI agents.

Every evaluation we run happens inside a simulated world. Thousands of agents run against those worlds in parallel, each run isolated and replayable, often inside a customer's own cloud. Nothing off the shelf does this. You'll design it and own the architecture from day one.

You'll work on:

• Simulated environments that spin up, reset, and replay on demand
• Running large fleets of agents quickly and cheaply
• Deploying securely into the most demanding enterprise environments
• The core architecture, and turning it into a product teams adopt on their own

Why it's exciting:

• Infrastructure here is the moat, not a dashboard on top of a database.
• What you build decides which customers we can say yes to.
• The runtime for agent simulation is still being invented.

You might be a fit if

• You're a strong backend or infrastructure engineer who has been early before
• You've built and run production systems, and you're excited to own the parts you haven't done yet
• You're AI-pilled: you build with LLMs, work alongside coding agents every day, and have opinions about where agents break
• You make strong architectural calls with incomplete information
• You typically have 3–10 years of experience

Nice to have

• Cloud infrastructure across AWS, GCP, or Azure
• Containers, sandboxing, and isolation
• Distributed systems and data pipelines
• Enterprise security and compliance

Probably not a fit

• Front-end only
• Roles where you never made the architectural calls
• Careers spent entirely inside very large companies

What we offer

• Founding equity and competitive cash
• One of the first hires, working directly with the founder and customers from day one
• Ownership of the platform architecture from the start
• A beautiful office in FiDi
• Breakfast, lunch, and dinner
• Medical, dental, and vision coverage
• Equinox membership or a fitness stipend
• Essentially unlimited budget for AI tools and tokens
• Relocation support if you're moving to San Francisco