Senior Frontend Engineer, Payments

Location: Belgrade; Lisbon Workplace: OnSite Aghanim is an integrated commerce, liveops automation, community engagement, and payments platform for video games.   Mobile games have traditionally depended on app stores for distribution, payments, and player relationships. We believe there is a better way. Aghanim helps game studios build direct relationships with players, sell directly, and build their future on their own terms. Today, more than 100 games worldwide are already building this future with Aghanim.   Our team brings together people across Los Angeles, New York, Seoul, Beijing, London, Lisbon, Belgrade and other locations around the globe, with deep expertise in gaming, fintech and technology. We move quickly, keep communication direct, and focus on getting things done. We believe the best people thrive when they have autonomy, ownership, and a stake in the company's success. [https://app.ashbyhq.com/api/images/user-content/4f457f07-466b-477b-b552-fbbabd850111/2de3a7cd-8843-41a9-8bbe-ceb897a42c4a/Logo%20(horizontal).svg] We're looking for a Senior Frontend Engineer to join our payments team and help build and evolve our Checkout experience. Checkout is the final step in a mobile game purchase — the interface where players around the world complete payments every day. It operates across 200+ countries and supports 130 currencies, 25 languages, and 100+ payment methods. Its performance, reliability, and UX directly impact payment success rates, conversion, and revenue. KEY RESPONSIBILITIES - Build and improve Checkout: add new payment flows, payment methods, and third-party SDK integrations. - Build a fast, simple, mobile-first interface that works well across browsers, WebViews, and in-app browsers, including on low-end devices and slow networks. - Improve Checkout performance and stability by finding bottlenecks and fixing issues in key user flows. - Use product data and experiments to find friction in the Checkout funnel, test ideas, and improve conversion. - Investigate production issues using logs, traces, product events, and metrics, and work with APIs and backend services when needed. - Take part in technical decisions and code reviews and help maintain frontend code quality. REQUIRED QUALIFICATIONS - 5+ years of professional frontend development experience with strong TypeScript and React skills. - Strong understanding of browsers, networking, and mobile web. - Experience improving web performance, including FCP, LCP, profiling, bundle size, and resource loading. - Experience building payment or other transactional flows, such as checkout, subscriptions, wallets, or payment SDK integrations. - Strong debugging skills and ability to investigate problems beyond the frontend layer. - Ability to own your work from implementation and release to stable operation in production. PREFERRED QUALIFICATIONS - Experience in fintech, payments, e-commerce, gaming, or other consumer products with a large mobile audience. - Understanding of payment concepts such as 3DS, payment statuses, saved payment methods, declines, and refunds. - Understanding of frontend security, including CSP, iframe security, and PCI scope. - Ability to read Go or Python and understand backend logic and APIs. - Experience using AI tools in day-to-day development. WHY JOIN US - World-class team – work alongside experienced professionals from around the globe who have built products used by millions of players - High growth, high impact – be part of a fast-growing company where ideas turn into products and reach customers in days, not months - Autonomy and ownership – we trust people to make decisions, take initiative, and drive results - Modern tools and technology – use AI, automation, and modern tools as part of your everyday work - Equity – participate in the company's growth and long-term success