Senior .NET Developer / Tech Lead

Project/Client: Fintech
Location: Lithuania
Start Date:ASAP
Duration: 12 months
Language:English

Role Overview:

We’re looking for a Senior .NET Developer / Tech Lead to join our engineering team and build payment-focused backend solutions in a regulated fintech environment. This is a hands-on role combining software development with technical leadership. You’ll design and develop backend services, contribute to technical and architectural decisions, and help the team maintain high engineering standards.

Key Responsibilities:

• Design and develop backend services using C# / modern .NET

• Contribute to technical design and architectural decisions

• Build integrations with REST APIs, third-party platforms, messaging, and file-based interfaces

• Ensure code quality through code reviews and engineering best practices

• Mentor developers and lead technical discussions

• Work with SQL, relational databases, CI/CD, and Docker

• Build secure, reliable, and scalable software solutions

• Collaborate with product, compliance, QA, and other engineering teams

Must-Have Requirements:

• 7+ years of hands-on C# / .NET experience

• Strong backend development experience

• Experience with REST APIs, integrations, and distributed systems

• Strong SQL and relational database experience

• Experience with Docker and CI/CD

• Understanding of secure and reliable software development

• Experience as a Senior Engineer, Tech Lead, or similar

• Ability to take technical ownership and guide other developers

Nice to Have:

• Experience in payments, banking, fintech, or financial services

• Experience in a regulated / compliance-driven environment

• Knowledge of ISO 20022 / SEPA

• Understanding of clearing, settlement, or payment processing

• Experience with Azure or AWS

• What we offer

  • Model: B2B contract with Bonapolia - one contract, one monthly invoice

  • Rate: negotiated per candidate seniority and client budget

  • Payment: monthly invoice, paid on the same schedule the client pays us (usually 30 days)

  • Contract written under your country's law

  • We handle the client-side paperwork: MSA, NDA, invoicing

  🏢 About Bonapolia

  Bonapolia is a family-owned IT staff augmentation team based in Lisbon. We build engineering teams for product companies and IT consultancies across Europe and the US.

  More at bonapolia.com
  
  📩 Ready to Join?
  We look forward to receiving your application and welcoming you to our team!