Freelance 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