Staff Software Engineer

About the role

You will own the platform that powers how Headway runs experiments across every team. You will design and implement the core primitives that assign users to experiments, record what a person actually saw, and recognize the same person across devices and between anonymous browsing and authenticated sessions. You will evaluate and consolidate our experimentation and feature flagging stack, choosing the long-term direction for LaunchDarkly and Statsig. You will make AI a practical part of the workflow, from validating an experiment setup before it starts to catching a broken experiment automatically instead of discovering it in a Slack thread a week later. You will evolve experimentation capabilities to support market-based testing, including whole geographic markets and long-holdout groups for multi-sided marketplace impact analysis. The role is both a platform and a program, where you will raise how well the entire company experiments through defaults, review, documentation, and education. You will sit in the Patient organization, where the highest volume of experiments happens, and serve the entire company as a trusted technical partner.

Key facts

What you'll do

Define and deliver the core architecture for experimentation, including user assignment, event tracking, and identity resolution across anonymous and authenticated states.

Evaluate and consolidate the experimentation and feature flagging stack, making decisions about LaunchDarkly and Statsig for long-term platform strategy.

Design primitives for market-based testing, such as holding out whole geographic markets and running long-holdout groups for multi-sided marketplace insights.

Partner with product and data teams to translate experimental design needs into robust platform capabilities that scale reliably.

Implement AI-assisted workflows that validate experiment setup before launch and automatically detect anomalies or broken experiments in production.

Own the reliability and performance of the experimentation platform, ensuring consistent behavior across the patient search and provider onboarding journeys.

Lead best practices for experimentation, including review, documentation, and education to enable teams to run trustworthy experiments independently.

Collaborate with data science and analytics to ensure experiments produce valid, measurable outcomes that inform high-stakes product decisions.

Define and evolve standards for feature flags, experiment rollouts, and gradual migrations to reduce risk and improve operational clarity.

Champion security and compliance considerations specific to experimentation, including auditability and privacy in a healthcare environment.

Drive technical discovery and prototyping to assess new tooling, frameworks, and patterns for experimentation at scale.

Work closely with the Patient organization to prioritize experimentation initiatives that unlock the highest value for therapists and patients.

Establish clear ownership and boundaries for experimentation platforms, balancing centralization with team autonomy.

Communicate roadmap priorities and tradeoffs to stakeholders, acting as a part product manager for the experimentation platform.

Invest in developer experience and self-serve tooling that makes running experiments intuitive and low-friction for end users.

Requirements

You have 8+ years of professional software engineering experience, with a strong track record of building and operating high-scale systems.

You are deeply proficient in Python and TypeScript, with demonstrated ability to write clean, maintainable, and testable code in both languages.

You have hands-on experience with FastAPI and SQLAlchemy, building APIs that are performant and secure.

You have shipped production-grade React and Remix applications, with a solid understanding of frontend architecture and user experience.

You have managed experimentation, feature flagging, and analytics infrastructure, including LaunchDarkly and Statsig in live environments.

You are comfortable working with datastores such as Postgres and Redis, and you understand how to optimize queries and manage schema evolution at scale.

You have operated infrastructure on AWS, working with Fargate, ECS, S3, and related services to deliver reliable, secure solutions.

You have experience with streaming platforms such as Spark and Kafka, and with monitoring tools like Datadog, PagerDuty, and Sentry.

You are comfortable using Git and GitHub to manage complex codebases, enforce standards, and enable collaboration across distributed teams.

Nice to have

Experience building and operating experimentation platforms in regulated industries such as healthcare.

Background in marketplace or two-sided platform dynamics, including multi-sided measurement and market-based testing approaches.

Deep experience with identity resolution and cross-device tracking in privacy-constrained environments.

Familiarity with AI-assisted development tools and techniques for integrating LLMs into engineering workflows.

Practical knowledge of dbt, Snowflake, and modern data stack patterns for analytics and experimentation.

Practical notes

This is a full-time remote role. We do not specify hours on the page, and there is no travel, visa, or application deadline mentioned in the source material.