Sr. Software Engineer (Backend)

About IXOPAY IXOPAY is the enterprise-grade global payment infrastructure platform built for the era of agentic commerce. We equip merchants and enterprises with AI-driven intelligence, payment orchestration, advanced tokenization, and the tools to optimize every stage of the payments journey. From intelligent routing and compliance to customizable modules and enterprise-scale orchestration, IXOPAY helps businesses integrate faster, improve payment performance, and expand globally with confidence. At IXOPAY, our people are our greatest strength. Our collaborative culture is built on shared values that guide how we work, innovate, and support our customers. About the Role We're looking for a Senior Software Engineer to join our Engineering team and help build the backend foundation of IXOPAY's next-generation, AI-first payment orchestration platform. In this hands-on role, you'll design and build the services that power intelligent payment routing, connector management, token intelligence, and platform configuration. You'll work on complex, high-scale systems that enable merchants to optimize payment performance while building secure, extensible infrastructure for the future of payments. You'll collaborate closely with Product, AI, and Engineering teams, mentor junior engineers, and play a key role in shaping the architecture of a platform used by global enterprise customers. What You'll Do Design, build, and maintain scalable backend services using C# and .NET. Develop the core infrastructure that powers payment routing, connector management, and platform configuration. Design secure, extensible APIs that support both customer-facing applications and AI-powered workflows. Build reliable, observable services that process high-volume payment transactions with performance and resilience in mind. Collaborate with Product and AI teams to translate business requirements into scalable technical solutions. Contribute to platform architecture, engineering standards, and technical decision-making. Mentor junior engineers through code reviews, design discussions, and day-to-day technical guidance. Continuously improve system performance, security, reliability, and developer experience. What You'll Bring Required 5+ years of experience building production backend services. Strong experience with C# and the .NET ecosystem. Experience designing and building RESTful and/or event-driven APIs. Strong understanding of relational databases, data modelling, and distributed systems. Experience building secure, scalable cloud-based applications. Excellent problem-solving, communication, and collaboration skills. Ability to provide technical leadership while remaining hands-on in development. Preferred Experience in payments, FinTech, or other high-volume transaction processing environments. Experience with Azure services such as App Configuration and Key Vault. Knowledge of payment routing, PSP integrations, tokenization, or payment orchestration platforms. Experience building APIs or services that integrate with AI or LLM-based applications. Familiarity with plugin or adapter architectures and extensible platform design. Understanding of PCI DSS, credential management, and payment security best practices. Experience mentoring engineers in an agile development environment. Why Join IXOPAY? At IXOPAY, you'll help define the architecture behind the next generation of enterprise payment infrastructure. You'll work on technically challenging problems at the intersection of distributed systems, AI, and global payments while collaborating with a small, highly experienced engineering team where your contributions have a direct impact. We offer: Competitive salary and benefits Professional growth and development opportunities A collaborative, supportive engineering culture The opportunity to shape a modern AI-first platform from the ground up US Benefits Include Medical, Dental, and Vision Insurance Flexible Spending Account (FSA) and Health Savings Account (HSA) Employer-paid Life, AD&D, Short-Term Disability, and Long-Term Disability Insurance Unlimited Paid Time Off and Paid Holidays 401(k) Plan with Employer Match Our Commitment to Inclusion We know great candidates don't always meet every qualification. If you're excited about this opportunity, we encourage you to apply—we'd love to hear what you can bring to IXOPAY. Equal Opportunity Employer IXOPAY is proud to be an Equal Opportunity Employer. We consider all qualified applicants without regard to race, color, religion, sex (including pregnancy, sexual orientation, gender identity, or gender expression), national origin, age, disability, genetic information, veteran status, or any other characteristic protected by applicable law. IXOPAY participates in E-Verify.