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.
Responsibilities
- Architect 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 transaction
- Build the Configuration Service — encrypted credential store, CRUD API, and tenant-scoped routing targets with a schema extensible to new plugins without migrations
- Design 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 changes
- Develop and maintain agentic anomaly detection across routing behavior and transaction patterns, feeding signals into a routing recommendation engine
- Collaborate with product and the AI agent team to translate business requirements into durable, observable backend services
- Mentor the Junior Engineer through code review, design discussions, and technical guidance
Skills
- 5+ years of professional software engineering experience building production backend services
- Strong backend proficiency in C#/.NET — our primary stack is .NET 10
- Experience designing APIs consumed by external systems or agents — REST, event-driven, or both
- Solid understanding of relational databases, data modeling, and schema design for high-throughput financial systems
- Background in payment systems, PSP integrations, tokenization infrastructure, or equivalent fintech backend complexity
- Familiarity with security patterns relevant to payment data: credential encryption, HMAC signing, token handling, and secrets management
- Comfort 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 team
- Experience integrating with LLM APIs or building MCP-compatible services
- Prior work with routing engines, rules-based decisioning systems, or capability registries
- Platform or SDK design experience — defining contracts and interfaces that other developers build against
- Familiarity with adapter/plugin architectures for integrating third-party payment providers
- Exposure to AI coding tooling and agent-assisted development workflows
- Background in PCI DSS compliance engineering — scoping, segmentation, and minimizing cardholder data exposure
- Experience with network tokenization, credential-on-file optimization, or Account Updater workflows
Benefits
- Competitive salary and benefits
- Opportunities for growth and development
- A collaborative and supportive team environment
- Medical, Dental & Vision Insurance
- Flexible Spending Account (FSA) & Health Savings Account (HSA)
- Employer-paid Life, AD&D, STD & LTD Insurance
- Unlimited PTO & Paid Holidays
- 401(k) Plan with Employer Match
Company Overview
IXOPAY 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.