Senior iOS Engineer (Core) At WHOOP, we’re on a mission to unlock human performance and healthspan. WHOOP empowers members to perform at a higher level through a deeper understanding of their bodies and daily lives. Our wearable technology monitors vital physiological metrics to offer personalized insights that enhance fitness, health, and recovery. As a Senior iOS Engineer on the Core team, you will build the foundations that power the WHOOP iOS app—owning platform capabilities, shared architecture, and reliability/performance improvements that unlock faster delivery for product teams and a consistently great experience for members. You will lead technical planning for complex initiatives, mentor other engineers, and raise the bar for engineering excellence across the iOS stack. \nRESPONSIBILITIES: Lead the design and implementation of core iOS platform capabilities (for example, app architecture, navigation patterns, shared UI components, networking, persistence, and feature flagging) Drive technical planning for initiatives, including scoping and sequencing work, identifying dependencies and risks, and communicating tradeoffs and timelines to stakeholders Deliver high-quality, member-facing iOS features in Swift, collaborating with cross-functional partners to ensure requirements are met and outcomes are measurable Improve app reliability, performance, and maintainability through testing, observability, crash and performance monitoring, and disciplined release practices Establish and evolve shared engineering standards through code reviews, documentation, and architectural discussions, influencing patterns used across iOS development Mentor and support other engineers through pairing, feedback, and knowledge sharing, helping grow individual capability and the overall health of the codebase QUALIFICATIONS: Significant experience building, testing, debugging, and shipping native iOS applications in production environments Strong proficiency with Swift and iOS frameworks (for example, SwiftUI, UIKit, XCTest) and experience with modern architecture patterns (for example, MVVM) Experience leading technical planning and delivery for ambiguous, cross-cutting iOS initiatives (for example, modularization, large refactors, performance programs, or reliability initiatives) Strong foundation in iOS performance and reliability fundamentals (for example, memory management, profiling, and concurrency with Swift Concurrency and/or GCD) Experience integrating mobile apps with backend services and APIs (for example, RESTful APIs, authentication flows, and resilient networking) Familiarity with common iOS tooling and workflows (for example, Xcode, Git, CI, Fastlane, Swift Package Manager, CocoaPods) Demonstrated ability to collaborate effectively across functions (for example, Product, Design, QA, Data, and Backend Engineering) and communicate clearly with technical and non-technical audiences Bonus: Experience building shared mobile foundations across platforms (for example, collaborating closely with Android on patterns and releases), or contributing to backend services and APIs (for example, Java) \nLearn more about our Software Org and how to be successful in your engineering career at WHOOP via our Career Framework. This role is based in the WHOOP office located in Boston, MA. The successful candidate must be prepared to relocate if necessary to work out of the Boston, MA office. Interested in the role, but don’t meet every qualification? We encourage you to still apply! At WHOOP, we believe there is much more to a candidate than what is written on paper, and we value character as much as experience. As we continue to build a diverse and inclusive environment, we encourage anyone who is interested in this role to apply. WHOOP is an Equal Opportunity Employer and participates in E-verify to determine employment eligibility. It is unlawful in Massachusetts to require or administer a lie detector test as a condition of employment or continued employment. An employer who violates this law shall be subject to criminal penalties and civil liability. The WHOOP compensation philosophy is designed to attract, motivate, and retain exceptional talent by offering competitive base salaries, meaningful equity, and consistent pay practices that reflect our mission and core values. At WHOOP, we view total compensation as the combination of base salary, equity, and benefits, with equity serving as a key differentiator that aligns our employees with the long-term success of the company and allows every member of our corporate team to own part of WHOOP and share in the company’s long-term growth and success. The U.S. base salary range for this full-time position is $150,000-$215,000. Salary ranges are determined by role, level, and location. Within each range, individual pay is based on factors such as job-related skills, experience, performance, and relevant education or training. In addition to the base salary, the successful candidate will also receive benefits and a generous equity package. These ranges may be modified in the future to reflect evolving market conditions and organizational needs. While most offers will typically fall toward the starting point of the range, total compensation will depend on the candidate’s specific qualifications, expertise, and alignment with the role’s requirements. Learn more about WHOOP.