Software Engineer, Frontend

An Introduction to Primer Primer is the world's primer payment infrastructure, founded by former leaders of Braintree and PayPal. We unify fragmented payment and finance systems into a single, intelligent platform, automating the entire payments lifecycle from acceptance and orchestration to reconciliation, FX, and financial operations. Trusted by leading merchants worldwide, we give finance, payments, and engineering teams the tools to move faster, reduce complexity, and unlock growth. Our open, modular platform connects to 150+ services across the payments ecosystem, while our expanding CFO product suite brings unified reconciliation, FX management, and financial visibility across markets and currencies. Backed by Accel, Balderton, ICONIQ, and Tencent, we're setting a new standard for how the world moves money. Which team will you be joining? You'll be joining the Acceptance team — the engineering domain responsible for the foundation of Primer's payment platform. Acceptance processes 10 million transactions a day across providers, markets, and payment methods. The team owns everything from the core payment infrastructure to the merchant-facing APIs, SDKs, and checkout experiences that sit on top of it. Frontend at this level in Acceptance means working on surfaces that real merchants ship to their customers — composable checkout components, developer tooling, and the UI layer that makes a complex payments platform actually usable. The quality bar is high because the stakes are real. You'll report to an Engineering Manager and work closely with backend engineers, product, and design across a team that values end-to-end ownership and engineers who care about what they build. What will you be doing? - Own frontend projects end-to-end — from scoping through to production — across Acceptance's payment surfaces, checkout components, and merchant-facing tooling. - Lead architectural decisions on the frontend systems you work on, contributing to design sessions and producing RFCs and ADRs with minimal reliance on more senior engineers. - Build UI that is composable, performant, and adaptable — payment experiences that merchants can configure and extend to fit their own products. - Monitor the impact of your work in production, use metrics and dashboards to catch issues proactively, and take full ownership when things need to be fixed. - Hold a high quality bar for your own code and raise concerns when you see things in the codebase that don't meet it. - Contribute to incident response when it matters — taking the lead, driving to resolution, and keeping stakeholders informed throughout. - Share knowledge actively and help raise the quality and confidence of the engineers around you.