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Senior Software Engineer (C#, .NET, + AWS)

Rec2Tech
Department:Software Engineer
Type:REMOTE
Region:EU
Location:Poland
Experience:Mid-Senior level
Estimated Salary:PLN120,000 - PLN180,000
Skills:
C#.NETAWSDOCKERPOSTGRESQLDYNAMODBDATADOGAUTH0GITHUB ACTIONSEF COREHANGFIRERESTEASENUNITAPIPAYMENTSFINTECHSECURITYCOMPLIANCE
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Job Description

Posted on: December 13, 2025

Senior Software Engineer (C# .NET)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.

The Role (What You’re Really Signing Up For)

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.

What You’ll Be DoingBackend & API Engineering

  • 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

Payments, Crypto & Real-World Complexity

  • 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

Security, Risk & Compliance (By Design)

  • 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

Cloud, Infrastructure & Reliability

  • 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

Team & Ways of Working

  • 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

 The Technical Stack

  • 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

 Who This Role Is Really ForYou’ll Likely Thrive If You:

  • 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

This Role Is Probably Not for You If You:

  • 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.)

 Nice-to-Haves (Not Deal Breakers)

  • 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

What Makes This Worthwhile

  • 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

Final Note

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.

Originally posted on LinkedIn

Apply now

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