Senior Software Engineer

Location:

About IXOPAY

IXOPAY is the enterprise-grade global payment infrastructure platform built for the era of agentic commerce, equipping merchants and businesses with AI-driven intelligence, orchestration, advanced tokenization, and the tools to power every step of their payments journey. From routing and compliance to customized modules and full-scale orchestration, IXOPAY delivers the infrastructure for faster integrations, higher approval rates, and seamless global expansion.

We believe our people are our most valuable asset and that our culture is defined by our core values that align the organization with our mission and strategy.

About the Role

We're looking for a Senior Software Engineer to join our team, where you'll own the backend architecture for a next-generation AI-first payment orchestration platform. You'll design and build the core systems that unify routing configuration, connector management, and token intelligence under a single control plane — replacing manual, siloed workflows with an intelligent, extensible infrastructure layer.

This is a hands-on IC role with broad ownership. You'll work on a small, fast-moving team alongside a UI Developer and a Junior Engineer, augmented by AI agent tooling. You'll define the contracts other systems and agents build against, and you'll ship them to production.

What You'll Do

• 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

What We're Looking For

• 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

Nice to Have

• 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

What We Offer

• Competitive salary and benefits

• Opportunities for growth and development

• A collaborative and supportive team environment

US Benefits Include

• 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

Equal Opportunity Employer

IXOPAY is an Equal Opportunity Employer and provides equal employment opportunities to all employees and applicants without regard to race, color, religion, sex (including pregnancy, sexual orientation, and gender identity), national origin, age, disability, genetic information, veteran status, or any other status protected by applicable federal, state, or local law. IXOPAY participates in E-Verify.