Freelance .NET Developer

Wise Integration; United States; Remote; USD 79,000 - 101,000; Full time

Job summary

Wise Integration is seeking a Senior .NET Developer / Tech Lead in Lithuania for backend-focused payment solutions in a regulated fintech environment. This hands-on role blends software development with technical leadership, designing and building backend services, and guiding architectural decisions.

You will mentor developers, drive best practices, and collaborate with product, compliance, QA, and other engineering teams to deliver secure, scalable systems.

Qualifications

• 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.
• 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

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

Skills

C#

.NET

Backend development

REST APIs

SQL

Azure

AWS

Technical leadership

Tools

Docker

CI/CD

Azure

AWS

Job description

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

Задачи:

• 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

Требования:

• 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
• 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