Senior Software Engineer, Experimentation

Mixpanel • San Francisco, CA

18h

About The Position

As a Senior Software Engineer on Mixpanel’s team, you will own the technical design and delivery of features across Experiments, Feature Flags, Session Replay, and Heatmaps. The work spans the full stack, from React frontend experiences and Python backend services to high-throughput systems for flag evaluation and replay ingestion. You will partner with Product and Design to shape product direction and collaborate with teams such as AI Engine and Product Platform on shared systems and SDKs. This is a high-impact role on a small, senior team, with significant influence over the technical direction of products central to Mixpanel’s growth.

Mixpanel’s team builds products that help product teams test, ship, and observe changes. Its vision is to provide one place where teams can roll out a change, measure its impact, understand real-user experiences, and decide what to do next using the event data they already trust. The team owns controlled experiments, behavior-targeted feature flags, and Session Replay and Heatmaps for web and mobile.

Mixpanel is a product intelligence and analytics platform used by more than 29,000 companies. The company describes itself as an equal opportunity employer and encourages applicants from diverse backgrounds.

Requirements

• Bachelor’s degree in Computer Science, Mathematics, or a related field, or equivalent practical experience.
• At least 5 years of professional software engineering experience, with a track record of delivering quality solutions quickly.
• Experience building and operating production systems end to end, with ownership of reliability and correctness for products customers depend on.
• Expert-level depth in at least one area—systems, web, or data infrastructure—and a broad understanding of full-stack architecture.
• Experience owning technical design for complex projects and managing multiple concurrent workstreams.
• Strong cross-functional collaboration skills, including working effectively with teams and organizational stakeholders with little guidance.
• Sound judgment in prioritization, technology selection, and tradeoffs that consider technical, product, and business factors.
• A track record of mentoring other engineers and contributing to team growth.
• Strong technical communication skills; experience collaborating in an asynchronous remote environment is ideal.
• Desire to help teams build and decide faster in the AI era.

Nice To Haves

• React or TypeScript experience.
• Django or Python experience.
• Experience building or heavily using experimentation, feature flagging, or session replay products.
• Experience building high-throughput, low-latency services.
• Familiarity with analytics or observability platforms.
• Experience building with LLMs, AI agents, or tool-use frameworks.
• Comfort using AI coding tools such as Claude Code or Cursor in daily work.

Responsibilities

• Own the technical design of complex features end to end, from backend services and data models to frontend experiences.
• Make well-reasoned technical decisions that balance speed, quality, cost, and product considerations; anticipate problems and develop contingency plans.
• Drive reliability, observability, and operational excellence for production services, and address technical debt before it becomes a long-term problem.
• Partner with AI Engine to bring AI into how customers design, run, and understand experiments and replays.
• Collaborate with Product Platform and other teams on SDKs, shared infrastructure, and architectural decisions affecting the broader platform.
• Mentor engineers through code reviews, pairing, and one-on-one support.
• Serve as an escalation point for complex bugs and on-call incidents in the team’s domain.
• Work with Support and Solutions Engineering on customer escalations and technical questions from prospects.
• Partner with Product and Design to identify and lead future work beyond the current roadmap.

Benefits

• Comprehensive medical, vision, and dental care.
• Mental wellness benefit.
• Generous vacation policy and additional company holidays.
• Enhanced parental leave.
• Volunteer time off.
• For US employees: pre-tax benefits including 401(k), wellness benefit, and holiday break.
• Benefits and perks for contract positions may vary.

What This Job Offers

• Job Type: Full-time
• Career Level: Senior