Freelance Senior (.NET) Software Engineer (B2B Contract) in Vilnius, Vilniaus apskritis at WISE INTEGRATION

Location: Vilnius, Lithuania — preferably hybrid, or remote within the EU / UK

Contract period: 1 October 2026 – 31 December 2026

About the Role

We are looking for an experienced .NET Software Engineer to join a mature, highly skilled squad working on a modern, distributed banking platform.

You will contribute to the design and development of a scalable, reliable, and secure solution built around native AWS services and high-criticality data pipelines.

Key Responsibilities

• Design and develop robust enterprise applications using .NET 10.
• Build modern, distributed solutions leveraging native AWS services.
• Develop highly scalable and reliable solutions for high-criticality data pipelines.
• Contribute to maintaining high standards of software quality, performance, and security.
• Investigate and resolve incidents, bugs, and production issues.
• Work effectively within a self-organizing Scrum team and contribute to an agile way of working.
• Create and maintain comprehensive technical documentation where required.
• Collaborate closely with software architects, engineers, business analysts, and other stakeholders.
• Contribute to the development of a modern, robust, and secure banking platform.
• Stay current with emerging technologies and contribute to continuous technical improvement.

Requirements

• 3–5+ years of professional experience developing and delivering robust enterprise products or applications.
• Strong experience with .NET 10 / C#.
• Thorough understanding of cloud technologies, particularly AWS, including services such as:
• AWS Lambda
• Amazon S3
• Amazon SQS
• AWS Step Functions
• Amazon DynamoDB
• and other native AWS services.
• Experience with GitHub Enterprise.
• Hands-on experience with CI/CD automation.
• Experience with Infrastructure as Code (IaC), particularly Terraform.
• Experience working in Agile / Scrum environments.
• Bachelor's degree or higher in Engineering, Computer Science, or a related field.
• Upper-Intermediate English (B2+), both written and spoken.

Nice to Have

• Experience with enterprise-grade data platforms, particularly Databricks.
• Experience with message streaming / queueing platforms such as Apache Kafka.
• Experience working with distributed systems and high-volume data processing.
• Previous experience in banking or other highly regulated environments.

What You Can Expect

• Work alongside a mature team of highly skilled technology professionals.
• Opportunity to work with modern .NET and AWS technologies.
• Exposure to distributed systems and high-criticality data platforms.
• A self-organizing Scrum environment with a strong engineering culture.
• Collaboration with experienced architects, engineers, and business analysts.
• Opportunity to contribute to a modern banking platform where reliability, security, and scalability are critical.