Senior Software Engineer, Experimentation

Description

The company is a product intelligence and analytics platform used by more than 29,000 companies to understand how people use the products they build.

It combines analytics with AI that understands each customer's business, so teams can see what works, find what doesn't, and choose what to build next.

The company has raised $277M from investors including Andreessen-Horowitz, Sequoia, YC and, most recently, Bain Capital.

The team builds the experimentation, feature flagging, and session replay and heatmaps products. The goal is one place where product teams ship a change, measure its effect, watch real users react to it, and decide what to do next, all on event data they already trust.

These products are among the company's most promising growth areas, taking customers from understanding behavior to acting on it. They matter more in the AI era, when teams ship faster and need quick proof that their changes work.

Experimentation: controlled tests run on the behavioral data customers already analyze, with results teams can rely on when deciding what to ship.

Feature flagging: safe, gradual rollouts targeted by real user behavior, served by a high-throughput evaluation service in the critical path of customer products.

Session replay and heatmaps: how real people experience a product on web and mobile, showing the reasons behind the numbers.

This is a senior software engineering role owning technical design and delivery across these products, from React frontends to Python backend services and high-throughput systems such as flag evaluation and replay ingestion. You will work directly with Product and Design on future direction, and with AI Engine and Product Platform on shared systems and SDKs.

It is a small senior team with significant influence over the technical direction of products central to the company's growth.

Responsibilities

• Own the technical design of complex features, from backend services and data models through to frontend experiences.
• Weigh speed, quality, cost and product needs in technical decisions, anticipating problems and preparing fallback plans.
• Improve reliability, observability and operational health of services customers depend on, and address tech debt before it becomes a long-term problem.
• Work with AI Engine to bring AI into how customers design, run and interpret experiments and replays.
• Work with Product Platform and other teams on SDKs, shared infrastructure and architecture that affects the wider platform.
• Coach engineers through code reviews, pairing and 1:1s to help them grow technically.
• Serve as the escalation point for complex bugs and on-call incidents in the team's domain.
• Help Support and Solutions Engineering with customer escalations and technical questions from prospects.
• Work with Product and Design to identify and lead future work beyond the current roadmap.

Requirements

• Bachelor's degree in Computer Science, Mathematics or a related field, or equivalent practical experience.
• 5+ years of professional software engineering experience, with a record of delivering quality solutions quickly.
• Experience building and running production systems end to end, owning reliability and correctness for a product customers depend on.
• Expert-level depth in one area (systems, web or data infrastructure) and broad understanding of full-stack architecture.
• Experience leading technical design on complex projects while managing several concurrent workstreams.
• Strong cross-functional collaboration: you work well with other teams and stakeholders with little guidance.
• Sound judgment on priorities, technology selection and tradeoffs across technical, product and business considerations.
• A track record of mentoring engineers and contributing to team growth.
• Strong technical communication, ideally in an asynchronous remote environment.
• A desire to help teams build and decide faster in the AI era.
• Bonus: React and TypeScript experience.
• Bonus: Django and Python experience.
• Bonus: experience with experimentation, feature flagging or session replay products, as a builder or heavy user.
• Bonus: experience building high-throughput, low-latency services.
• Bonus: familiarity with analytics or observability platforms.
• Bonus: experience building with LLMs, AI agents or tool-use frameworks.
• Bonus: comfort using AI coding tools such as Claude Code or Cursor in daily work.

Conditions

The company is an equal opportunity employer that encourages applications from women, people with disabilities, veterans, underrepresented minorities and LGBTQ+ people, and considers applicants with arrest and conviction records under the San Francisco Fair Chance Ordinance or similar laws.

Benefits

• Medical, vision and dental coverage.
• Mental wellness benefit.
• Generous vacation policy plus additional company holidays.
• Enhanced parental leave.
• Volunteer time off.
• US extras: pre-tax benefits including a 401(k), a wellness benefit and a holiday break.
• Benefits and perks for contract positions differ from these.