Infrastructure Engineer — Sandbox Platform

We're shipping every product that companies need to run their business from their first day, to the day they IPO, and beyond. The operating system for folks who build software.

We started with open-source product analytics, launched out of Y Combinator's W20 cohort. We've since shipped more than a dozen products, including:

• A built-in data warehouse, so users can query product and customer data together using custom SQL insights.

• A customer data platform, so they can send their data wherever they need with ease.

• PostHog AI, an AI-powered analyst that answers product questions, helps users find useful session recordings, and writes custom SQL queries.

Next on the roadmap are CRM, Workflow, revenue analytics, and support products. When we say every product that companies need to run their business, we really mean it!

We are:

1. Product-led. More than 100,000 companies have installed PostHog, mostly driven by word-of-mouth. We have intensely strong product-market fit.

2. Default alive. Revenue is growing 10% MoM on average, and we're very efficient. We raise money to push ambition and grow faster, not to keep the lights on.

3. Well-funded. We've raised more than $100m from some of the world's top investors. We're set up for a long, ambitious journey.

We're focused on building an awesome product for end users, hiring exceptional teammates, shipping fast, and being as weird as possible.

• Transparency: Everyone can read about our roadmap, how we pay (or even let go of) people, our strategy, and how we work, in our public company handbook. Internally, we share revenue, notes and slides from board meetings, and fundraising plans, so everyone has the context they need to make good decisions.

• Autonomy: We don’t tell anyone what to do. Everyone chooses what to work on next based on what's going to have the biggest impact on our customers, and what they find interesting and motivating to work on. Engineers lead product teams and make product decisions. Teams are flexible and easy to change when needed.

• Shipping fast: Why not now? We want to build a lot of products; we can't do that shipping at a normal pace. We've built the company around small teams – autonomous, highly-efficient groups of cracked engineers who can outship much larger companies because they own their products end-to-end.

• Time for building: Nothing gets shipped in a meeting. We're a natively remote company. We default to async communication – PRs > Issues > Slack. Tuesdays and Thursdays are meeting-free days, and we prioritize heads down building time over perfect coordination. This will be the most productive job you've ever had.

• Ambition: We want to solve big problems. We strongly believe that aiming for the best possible upside, and sometimes missing, is better than never trying. We're optimistic about what's possible and our ability to get there.

• Being weird: Weird means redesigning an already world-class website for the 5th time. It means shipping literally every product that relates to customer data. It means building an objectively unnecessary developer toy with dubious shareholder value. Doing weird stuff is a competitive advantage. And it's fun.

We’re looking for an Infrastructure engineer that has experience designing, deploying, and maintaining high-performance infrastructure and cares about secure and isolated engineering environments. This person has a solid experience in backend engineering, more specifically in Python, Go, or Rust in a high-scale environment.

We're building the future of data, and a key part of that is giving our users secure, powerful, and isolated environments to run complex data workloads. This is a greenfield project to build our sandbox infrastructure from the ground up.

As an Infrastructure/Backend Engineer on the Managed Warehouse Team, you'll be the architect and builder of this critical system. You'll be tackling challenging problems around multi-tenancy, security, performance isolation, and cost optimization, all while setting the foundation for new PostHog products. If you love the idea of designing and implementing a core platform from scratch, working at the edge of infrastructure and security, and enabling whole new product categories, this role is for you.

This is a high-impact, hands-on role where you will:

• Design and Implement the Sandbox Platform: Be the primary engineer responsible for building the core sandbox infrastructure. This includes API design, backend logic, and the underlying orchestration.

• Enforce Hard Isolation: Design and implement mechanisms to run user-provided code and data workloads with strong security and performance isolation on tech (platforms?) like Kata Containers on Kubernetes (k8s) (though we’re open to better systems if you have a preference)

• Enable Core Products: The sandboxes will eventually power:

  • Our new DuckDB-based data warehouse product

  • Data science notebooks

  • PostHog AI sandboxes

• Manage performance and costs: Ensure the sandbox environments are highly performant, auto-scaling, and cost-efficient to run at PostHog scale.

• Infrastructure expertise: 3+ years of experience designing, deploying, and maintaining high-availability, high-performance infrastructure.

• Kubernetes chops: Deep, hands-on experience with production k8s environments. You should be comfortable extending k8s or interacting with its APIs at a low level.

• Backend engineering: Strong experience with our core backend language (Python/Django) or similar languages (Go, Rust) in a high-scale environment. Experience building and documenting robust APIs.

• Security & isolation: Experience with container runtime security, virtual machine isolation, and multi-tenancy challenges. You understand the difference between process and kernel isolation.

• Self-direction: Given this is a greenfield project, you thrive on ambiguity, can quickly prototype solutions, and can independently drive a technical vision from concept to production.

Nice to have

• Experience with secure container runtimes (e.g., Kata Containers, gVisor, Firecracker).

• Experience with data processing engines, particularly DuckDB, or OLAP technologies.

• Experience building infrastructure for AI/ML workloads or Jupyter environments.

If you have a disability, please let us know if there's any way we can make the interview process better for you - we're happy to accommodate!

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