Senior Software Engineer, Card Payments

Spectrum Search is partnered with a well-backed financial technology company building payment and card infrastructure for businesses operating internationally. The company is looking for a Senior Backend Software Engineer to develop resilient services supporting card transactions, partner integrations and developer-facing APIs. About the opportunity This is a senior engineering role within a team responsible for core card and payment infrastructure. The platform supports business payments, card issuing and financial operations through both user-facing products and programmable APIs. The role combines hands-on backend engineering with architectural input, operational ownership and close collaboration across product, risk, finance and compliance. The role You will design, build and operate production-grade backend systems supporting card transaction processing, fraud controls, card lifecycle management and external integrations. The environment is service-oriented and distributed, with a strong focus on correctness, reliability and observability. You will contribute to technical decisions around asynchronous processing, fault tolerance, performance and maintainability while helping improve engineering practices as the platform scales. Key responsibilities Design and develop backend services supporting card transactions, fraud detection and card programme managementBuild and maintain integrations with external partners and developer-facing application programming interfaces, or APIsContribute to system architecture and technical decision-making across distributed servicesDesign for performance, fault tolerance, resilience and maintainabilityDevelop clean, observable and well-tested production codeWork closely with Product, Risk, Finance and Compliance to deliver robust financial systemsParticipate in code reviews, incident response and ongoing reliability improvementsImprove engineering tooling, development practices and system design as the platform evolves Essential requirements Proven experience designing, building and operating production-grade backend systemsStrong backend development experience using a typed language such as TypeScript, Java or GoSolid understanding of distributed systems, including asynchronous processing, retries, observability and eventual consistencyAbility to make sound technical trade-offs across correctness, performance and maintainabilityExperience working effectively with cross-functional stakeholdersClear communication skills and the ability to explain technical decisions and trade-offsComfortable working in an evolving product and engineering environment Nice-to-haves Experience with card payments, card networks, 3D Secure, PCI environments, tokenisation or chargeback systemsExperience building software within regulated or compliance-sensitive environmentsHands-on experience with TypeScript, Node.js, NestJS and AWSExperience developing platforms with external APIs or partner integrationsExperience working within scaling technology companies Location and remote setup This is a fully remote opportunity for candidates based in the United Kingdom, Ireland, Poland or the Czech Republic.