Senior iOS Engineer

About Polymarket Polymarket is the world's largest prediction market platform. We enable individuals to express views on real-world events by trading on outcomes across politics, economics, sports, culture, and current affairs. Built as a peer-to-peer marketplace with no centralized "house," Polymarket aggregates diverse opinions into transparent, market-based probabilities that reflect collective expectations about the future. We're growing fast — both in terms of volume ($21B traded in 2025) and adoption as an alternative news source. Our ambition is to become a ubiquitous beacon of truth in global media and we need your help adding fuel to the fire. About the Role Polymarket is looking for a Senior iOS Engineer to help build our iOS product as we invest seriously in mobile. This is a high-ownership role for someone who understands what it takes to build a great trading or wagering experience on mobile — the performance requirements, the real-time data challenges, the UI patterns that make fast-moving information feel intuitive rather than overwhelming. You'll work closely with product, design, and engineering leadership to deliver a high-quality iOS experience and help raise the bar across the mobile codebase. The right person has been in this world before: they know what a great trading or sportsbook app feels like from the inside, and they want to build something better. What You'll Do Take end-to-end ownership of Polymarket's iOS experience, from technical architecture and performance to product quality and release discipline Make and own architectural decisions for the iOS platform, ensuring the codebase is built to scale and maintained with rigor as the product grows Design and implement experiences that handle live market data, fast-moving prices, and real-time order state in a way that feels fast and reliable to users Lead code reviews, establish strong iOS engineering standards, and help grow the capability of the broader mobile team Work closely with product, design, and backend teams to align on priorities, define APIs and data contracts, and ship high-quality experiences end-to-end Help shape how Polymarket thinks about mobile as a platform, including architecture decisions that set up the team for scale What We're Looking For Significant iOS engineering experience, with a track record of shipping and owning high-quality iOS applications in production Deep experience building trading, financial, or sportsbook applications — you understand the product domain and the technical demands that come with it Strong knowledge of Swift and the iOS SDK, with solid instincts around performance, memory management, and real-time data handling Experience building apps that consume live data feeds and display fast-moving information reliably and smoothly A high bar for product quality — you care about how things feel, not just whether they work Comfortable operating with broad ownership in a fast-moving environment Strong cross-functional communication skills — you work well with product, design, and backend engineers (Plus) Familiarity with WebSockets, streaming APIs, or other real-time data infrastructure (Plus) Experience leading or mentoring iOS engineers (Plus) Background in a high-growth startup environment Benefits Competitive salary & equity Unlimited PTO Full Health, Vision, & Dental coverage 401k match Hardware setup: new MacBook Pro, big display, & accessories