Senior Backend Software Engineer (C# .NET) - Payments & Financial Infrastructure

Payments & Financial Infrastructure (Remote)

A fast-scaling global payments infrastructure company is building the financial rails that move real money across borders at speed, at scale, and with zero tolerance for failure.

The platform powers cross-border transactions for SMEs and enterprises using a blend of traditional banking networks and stablecoin-backed blockchain rails. Transaction sizes are meaningful. The systems are live. The consequences are real.

The engineering team is distributed, lean, and fast-moving. Decisions are made quickly. Priorities shift. External partners change things without warning. The expectation is simple: build systems that hold up in the real world.

This is not a “feature factory” role.

This is financial infrastructure.

They are now hiring a Senior Software Engineer (C# .NET) to play a key role in shaping and stabilising their backend payments platform.

As a Senior Software Engineer, you’ll own and evolve critical backend services that sit directly in the path of money movement.

You’ll:

• Design and build API-driven services that process real payments
• Integrate with banks, payment providers, identity platforms, and blockchain rails
• Balance speed vs safety, often with incomplete information
• Take responsibility when things go wrong not just when they go right

This role suits someone who has already worked in regulated, high-risk systems and understands that elegance matters less than reliability.

• Design and build secure, scalable APIs in .NET 8 / C#, powering payment and stablecoin transactions
• Own backend services end-to-end — from design through production support
• Build background processing, scheduled jobs, and webhook-driven workflows
• Integrate with third-party payment, banking, KYC and identity providers

• Implement logic that touches real money, not test data
• Build and maintain integrations across traditional rails and blockchain-backed stablecoin flows
• Create mock services and defensive layers for partners without stable test environments
• Design systems that expect breaking changes outside your control

• Implement secure API patterns: authentication, encryption, auditing and monitoring
• Treat financial data with the caution it deserves
• Build systems that work within regulatory and compliance constraints rather than fighting them

• Deploy and operate services on AWS (Lambda, EC2, DynamoDB, S3)
• Collaborate closely with DevOps on CI/CD pipelines (GitHub Actions)
• Build containerised services (Docker) designed for scalability and resilience
• Monitor production systems using tools like DataDog, catching issues early

• Work closely with product and engineering to convert evolving requirements into stable systems
• Review code, raise the bar, and challenge risky assumptions
• Be comfortable with context-switching between BAU stabilisation and new feature work
• Communicate clearly in a fully remote, distributed team

• Backend: .NET 8, C#, EF Core, Hangfire, RestEase, NUnit
• Data: PostgreSQL, DynamoDB
• Infrastructure: AWS, Docker, GitHub Actions
• Auth & Observability: Auth0, DataDog
• Domain: Payments, identity verification, banking partners, stablecoin rails

• Have 5+ years of building production backend systems in C# .NET
• Have worked in fintech, banking, payments, or regulated environments
• Understand that money is risk, not just data
• Are calm under pressure and methodical when things break
• Can operate without perfect specs or stable third parties
• Take ownership instead of waiting for instructions
• Prefer reliability and clarity over shiny greenfield builds

• Need everything fully specified before you start
• Prefer slow, linear delivery cycles
• Avoid BAU, optimisation, or legacy improvement work
• Get frustrated by external dependencies you don’t control
• Are uncomfortable dealing with production responsibility

(Both kinds of engineers are good — just not for this role.)

• Experience with blockchain or stablecoin-based payment flows
• Hands-on use of DataDog for logs, metrics, and alerting
• Familiarity with Auth0 or similar auth providers
• Experience building integration-heavy systems with multiple external APIs
• Exposure to financial compliance or regulated domains

• Real ownership: You’ll work on systems that matter, not internal tooling nobody uses
• High impact: Your decisions directly affect real-world payments and customers
• Fast growth: Early-stage scale means fast learning and expanding responsibility
• Distributed team: Remote-first, pragmatic, outcome-focused
• Meaningful work: You’re enabling faster, more accessible financial infrastructure globally

This environment rewards engineers who are:

• Thoughtful
• Cautious
• Accountable
• Comfortable with ambiguity

It is not about being the loudest or fastest,

It’s about building systems that don’t break when it matters most.