Senior/Mid Frontend Engineer - React at sensortower

Fraud warning: It's common for scammers to create positions that look legitimate on other sites.  To ensure your submission is considered, only apply for positions at Sensor Tower through our company website or through posts directly associated with Sensor Tower company profiles on sites such as LinkedIn, Indeed, BuiltIn or Hackajob. At no point will Sensor Tower ever ask for money, credit card, or bank account information to complete a job application.  Communications received from Sensor Tower are only sent by e-mail addresses ending in sensortower.com.   All Sensor Tower interviews will be conducted via phone or Zoom.  At no time will a conversation be moved to an alternative email outside of sensortower.com or text.  Should an issue arise that you feel we should be aware of, please contact us. Please provide your resume when applying. To all recruitment agencies: Sensor Tower does not accept third party resumes. Please do not send resumes to our jobs alias, Sensor Tower employees or any other organization location. Sensor Tower is not responsible for any fees related to unsolicited resumes.  Sensor Tower will not pay any third-party agency or company that does not have a signed agreement with Sensor Tower. About this role: Would you enjoy the fast-paced excitement of a startup mindset? Are you interested in architecting high-visibility, rapid-release products? Do you value mentoring talented engineers and driving technical excellence? Join us in our journey to change how the world gains insights in digital marketing!   Apply now!   Role Summary: As a Senior Frontend Engineer at Sensor Tower, you will not only build features, you will define how we build them. You will take ownership of major technical components, ensuring our applications are scalable, maintainable, and fast. In our lean and flat organization, your voice will shape the technical direction of our product, helping us deliver an intuitive, fluid user experience that helps our customers understand the digital ecosystem. Fulfill Your Potential With Us • Architect and deliver complex, scalable frontend systems that are simple and effective, removing unnecessary complexity from our codebase. • You will partner with Product Managers to co-author requirements and shape the scope, ensuring engineering feasibility is considered during ideation, not just execution. • Lead technical decision-making for medium-to-large scoped features, taking responsibility for the successful delivery of value to the customer, not just the completion of tickets. • Mentor junior and mid-level engineers through code reviews, pair programming, and by instilling quality-first habits across the team. • Take ownership of the frontend stack by proactively identifying bottlenecks, technical debt, or systemic issues and driving the initiatives to fix them. • Advocate for and drive best practices in React, TypeScript, and web performance optimization across the engineering organization. • Collaborate deeply with Data Science and Backend Engineers to ensure seamless data flow and end-to-end system reliability, and use these partnerships to progressively expand your expertise across the full stack. Experience We Are Looking For • Software engineering experience with a deep specialization in modern JavaScript, TypeScript, and React. • Proven ability to architect complex state management. While our stack relies on TanStack Query and Zustand, we value engineers who understand the principles and can adapt expertise from other libraries like Redux or MobX. • ​​You can design systems that handle complexity without becoming complicated, prioritizing long-term maintainability. • Experience elevating the skills of peers. You don't just review their code; you teach patterns and best practices. • Competence in writing robust and efficient unit and integration tests using frameworks like Jest, Cypress, or Playwright. • Deep understanding of web performance, browser internals, and optimization techniques for data-heavy applications. • A "Product Owner" mindset. You care deeply about the "why" behind every feature, viewing code as a tool to solve real user problems. You are comfortable pushing back on requirements and proposing alternative solutions that drive better business outcomes and user experiences. Nice To Have • Experience in data visualization and analytics (handling large datasets, heavy DOM manipulation). • A portfolio, GitHub history, or technical writing that demonstrates clean code, an eye for design, and the ability to solve complex architectural challenges. • Familiarity with Ruby on Rails framework and NoSQL/Columnar databases (MongoDB, Clickhouse). Blog Posts Read more about some of our Technical challenges here (written by members of our engineering team):  [Upgrade to PRO to see link] [Upgrade to PRO to see link]