Senior Software Engineer, Experimentation

What we own

• Experiments: Controlled experiments that run on the same behavioral data customers already analyze in Mixpanel, with results teams can trust when they decide what to ship
• Feature Flags: Safe, gradual rollouts targeted by real user behavior, powered by a high-throughput evaluation service that runs in the critical path of our customers' products
• Session Replay and Heatmaps: A view of how real people experience a product across web and mobile, so teams can see the why behind the numbers

About the Role

As a Senior Software Engineer on the team, you'll own the technical design and delivery of features across Experiments, Feature Flags, Session Replay, and Heatmaps. You'll work across the full stack, from React frontend experiences to Python backend services to high-throughput systems like flag evaluation and replay ingestion. You'll partner directly with Product and Design to shape where these products go next, and collaborate with teams like AI Engine and Product Platform on shared systems and the SDKs that power our products.

This is a high-impact role on a small, senior team where you'll have significant influence over the technical direction of products that are central to Mixpanel's growth.

Responsibilities

• Own technical design for 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, anticipating problems and developing contingency plans
• Drive reliability, observability, and operational excellence for services that customers depend on in production, addressing tech 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 that affect the broader platform
• Mentor engineers on the team through code reviews, pairing, and 1:1 support, helping them grow technically
• 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 areas of future work beyond the current roadmap

We're Looking For Someone Who Has

• Bachelor's degree in Computer Science, Mathematics, a related field, or equivalent practical experience
• 5+ years of professional software engineering experience with a proven track record of delivering quality solutions with speed
• Experience building and operating production systems end to end, with real ownership of reliability and correctness in a product customers depend on
• Expert-level depth in at least one area (systems, web, or data infrastructure) with broad understanding of full-stack architecture
• Experience owning technical design for complex projects and managing multiple concurrent workstreams
• Strong cross-functional collaboration skills: you work effectively with other teams and organizational stakeholders with little guidance
• Sound judgment in setting priorities, selecting technologies, and making tradeoffs that factor in technical, product, and business considerations
• A track record of mentoring other engineers and contributing to team growth
• Strong technical communication, ideally with experience collaborating in an asynchronous remote environment
• A desire to help teams build and decide faster in the AI era

Bonus Points For

• React / TypeScript experience
• Django / Python experience
• Experience with experimentation, feature flagging, or session replay products, as a builder or a heavy user
• 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 (Claude Code, Cursor, etc.) in your daily work

Additional Resources

• Engineering Life Page
• Engineering Blog

Benefits and Perks

• Comprehensive Medical, Vision, and Dental Care
• Mental Wellness Benefit
• Generous Vacation Policy & Additional Company Holidays
• Enhanced Parental Leave
• Volunteer Time Off
• Additional US Benefits: Pre-Tax Benefits including 401(K), Wellness Benefit, Holiday Break

*please note that benefits and perks for contract positions will vary*

Culture Values

• Make Bold Bets: We choose courageous action over comfortable progress.
• Innovate with Insight: We tackle decisions with rigor and judgment - combining data, experience and collective wisdom to drive powerful outcomes.
• One Team: We collaborate across boundaries to achieve far greater impact than any of us could accomplish alone.
• Candor with Connection: We build meaningful relationships that enable honest feedback and direct conversations.
• Champion the Customer: We seek to deeply understand our customers' needs, ensuring their success is our north star.
• Powerful Simplicity: We find elegant solutions to complex problems, making sophisticated things accessible.

Why choose Mixpanel?

We're a leader in analytics with over 29,000 customers and $277M invested from prominent investors: like Andreessen-Horowitz, Sequoia, YC, and, most recently, Bain Capital. Mixpanel's pioneering event-based data analytics platform offers a powerful yet simple solution for companies to understand user behaviors and easily track overarching company success metrics.

Our accomplished teams continuously facilitate our expansion by tackling the ever-evolving challenges tied to scaling, reliability, design, and service. Choosing to work at Mixpanel means you'll be helping the world's most innovative companies learn from their data so they can make better decisions.