Senior Fullstack Engineer (ReactJS / Node.js)

ABOUT US We are Playbook, a leading creator platform for fitness, health, and wellness. Our mission is to help fitness creators build sustainable businesses, while enabling hundreds of thousands of users to live healthier lives. We are a fast-growing company in the fitness tech space, operating as a remote-first, product-driven team that values ownership, direct communication, and a strong growth mindset. We believe in “drivers, not passengers” — everyone is encouraged to take responsibility, think proactively, and act like an owner. ROLE OVERVIEW We’re looking for a Senior Full Stack Engineer (ReactJS / Node.js) to join our remote engineering team. You’ll work on meaningful, user-facing product features across the stack — building reliable backend services and polished frontend experiences. You’ll collaborate closely with Product and Design to deliver solutions aligned with real customer needs. This role is best suited for a senior individual contributor who enjoys hands-on development, understands that good architecture starts with clear contracts, and thrives on solving complex problems in a fast-moving startup environment. RESPONSIBILITIES - Design and implement new features across the stack (Node.js and ReactJS), with a strong focus on usability, clarity, and real user value, shaping APIs and GraphQL contracts as part of the feature design process. - Build and evolve backend services and APIs (REST and GraphQL) that power our platform. Focus on reliability, maintainability, and clean integrations with frontend applications and third-party services. - Work closely with Product Managers and Designers to translate requirements into practical, well-scoped technical solutions. - Contribute to Engineering Requirement Documents (ERDs) that define data models, API contracts, and integration points before implementation begins. - Write clean, readable, and well-tested code. Participate in code reviews and contribute to shared standards around quality, testing, and maintainability. Improve existing systems where it provides clear product or developer value. - Take responsibility for the features you build. Identify issues or gaps, propose improvements, and iterate based on feedback. You’re comfortable working with some ambiguity and adapting as requirements evolve. - Ability to break down product requirements into data models, GraphQL types, and frontend component structure before writing implementation code. REQUIREMENTS - 5+ years of professional software development experience, with a strong focus on full-stack JavaScript / TypeScript. Proven experience shipping production web applications end-to-end. - Strong experience with React.js and modern frontend patterns. Ability to build responsive, user-friendly interfaces with attention to detail and performance. Familiarity with TailwindCSS or similar styling frameworks. - Experience with Node.js, including designing GraphQL schemas and understanding resolvers, dataloaders, and API structure for maintainability. - Advanced TypeScript proficiency. Our codebase is heavily typed — you should be comfortable writing complex types, generics, conditional types, and using TypeScript to enforce contracts and model domain logic across the stack. - Active daily use of AI coding assistants (Claude Code, Codex, OpenCode, or similar) for development, debugging, and problem-solving. We expect engineers to leverage these tools to ship faster and work through complex problems. - Strong experience working with relational databases (PostgreSQL preferred), including schema design, query optimization, and reasoning about data consistency and performance. - Strong communication skills in English. Comfortable working in a remote, cross-timezone team and collaborating asynchronously. NICE TO HAVE - Experience with Node.js frameworks: Next.js, NestJS - Familiarity with MVVM or similar architectural patterns. - Familiarity with CI/CD pipelines, infrastructure as code, and improving observability and logging