[Remote] Senior Software Engineer

Note: The job is a remote job and is open to candidates in USA. IXOPAY is the enterprise-grade global payment infrastructure platform built for the era of agentic commerce. They are seeking a Senior Software Engineer to own the backend architecture for an AI-first payment orchestration platform, focusing on designing and building core systems for routing and token management.ResponsibilitiesArchitect and build the capability-aware Routing Engine — selecting downstream connectors based on instrument metadata (card brand, currency, BIN, transaction type) with fallback logic and structured routing events per transactionBuild the Configuration Service — encrypted credential store, CRUD API, and tenant-scoped routing targets with a schema extensible to new plugins without migrationsDesign and publish MCP-enabled APIs that allows AI agents to query, simulate, and propose changes — with a human-in-the-loop approval gate for high-impact changesDevelop and maintain agentic anomaly detection across routing behavior and transaction patterns, feeding signals into a routing recommendation engineCollaborate with product and the AI agent team to translate business requirements into durable, observable backend servicesMentor the Junior Engineer through code review, design discussions, and technical guidanceSkills5+ years of professional software engineering experience building production backend servicesStrong backend proficiency in C#/.NET — our primary stack is .NET 10Experience designing APIs consumed by external systems or agents — REST, event-driven, or bothSolid understanding of relational databases, data modeling, and schema design for high-throughput financial systemsBackground in payment systems, PSP integrations, tokenization infrastructure, or equivalent fintech backend complexityFamiliarity with security patterns relevant to payment data: credential encryption, HMAC signing, token handling, and secrets managementComfort with cloud infrastructure — we run on Azure (App Configuration, Key Vault)Strong communication skills and the ability to define architectural direction clearly for a small, collaborative teamExperience integrating with LLM APIs or building MCP-compatible servicesPrior work with routing engines, rules-based decisioning systems, or capability registriesPlatform or SDK design experience — defining contracts and interfaces that other developers build againstFamiliarity with adapter/plugin architectures for integrating third-party payment providersExposure to AI coding tooling and agent-assisted development workflowsBackground in PCI DSS compliance engineering — scoping, segmentation, and minimizing cardholder data exposureExperience with network tokenization, credential-on-file optimization, or Account Updater workflowsBenefitsCompetitive salary and benefitsOpportunities for growth and developmentA collaborative and supportive team environmentMedical, Dental & Vision InsuranceFlexible Spending Account (FSA) & Health Savings Account (HSA)Employer-paid Life, AD&D, STD & LTD InsuranceUnlimited PTO & Paid Holidays401(k) Plan with Employer MatchCompany OverviewIXOPAY provides digital payment processing solutions enabling independent, flexible and global payment processing for enterprise merchants. It was founded in 2014, and is headquartered in Vienna, Wien, AUT, with a workforce of 51-200 employees. Its website is https://www.ixopay.com.