Senior .NET Backend Developer

About the role: Companial’s R&D team is looking for a Backend Developer to join our skilled product team that always strives for excellence and uses the best practices and tools to achieve it.

You’re the right fit for us if you’re eager to grow, develop your skills in the latest .NET environment, enhance our already valuable product, and contribute to innovation by creating new features for our customers.

The position is based in Vilnius, Kaunas, or can be remote.

Selection process:
Companial does not use take-home assignments as part of the selection process. We value live communication — both the cultural fit and technical parts of the interview are conducted in real time (via remote calls). We ensure that the recruitment process is engaging, informative, and efficient.

If you enjoy working in a cross-cultural, product-based environment, with cutting-edge technologies, new R&D challenges, and the opportunity to build IT products that make a real impact on thousands of users worldwide, you are the person we’re looking for!

Responsibilities:

• Develop web applications using  .NET core v8 (C#) and later.
• Be the technical cornerstone for the team of developers.
• Evaluate new projects, suggest solutions and the best practices for tasks.
• Ensure high quality using coding standards, test driven development and code reviews (we use Azure DevOps for our CI/CD pipelines, pull requests and product backlog management).
• Work in team environment, teach and learn as necessary.

What we expect:

• 5+ years building and operating backend systems in C#/.NET (Core and Framework).
• 2+ years in a senior or technical-lead capacity, guiding architecture decisions and mentoring others.

Programming & Architecture: 

• Expert in C#, ASP.NET Core.
• Deep knowledge of microservices patterns (API Gateways, CQRS).
• Proven track record designing high-throughput, low-latency distributed systems.

Data Access: 

• Hands-on experience with Dapper or Cosmos DB SDK for high-performance queries.
• Familiarity with EF Core.
• Working knowledge of both Cosmos DB and Azure SQL Database for transactional and NoSQL scenarios.

Azure Infrastructure & Services:

• Hands-on with Azure compute (App Services, Kubernetes Service, Functions) and storage services (Blob, Tables).
• Azure Service Bus for reliable, scalable messaging between microservices.
• Experience designing for cost-efficiency and auto-scaling in cloud environments.

Soft Skills: 

• Strong communicator—able to explain complex designs to both technical and non-technical stakeholders.
• Proven collaborator in agile teams (Scrum/Kanban).
• Proactive problem solver: performance tuning, capacity planning, root-cause analysis.

Nice-to-Haves:

• Infrastructure as Code familiarity (ARM, Bicep or Terraform)—collaborating closely with the DevOps team
• Familiarity with Azure Active Directory, Microsoft Graph API, Managed Identities and Conditional Access
• Experience integrating with internal Microsoft services or APIs (Partner Center APIs, CSP billing endpoints)
• Understanding of Microsoft’s security/compliance standards (ISO, GDPR, CIS Benchmarks)
• On hand experience with Blazor Pages and Azure Functions

We offer:

•  A highly skilled international team working with leading Microsoft-based technologies.
• Be part of a team that supports each other and shares knowledge openly.
• Work in a company where values matter — We Care, Own, Create, and Enjoy.
• Training and development opportunities.
• An informal and social working environment in a fast-growing international IT organization.
• Additional vacation days.
• Flex benefits bonus focused on health and well-being.
• Health insurance (after the probation period).
• A product-based environment with a strong focus on code quality and work-life balance.
• Life and risk insurance.
• A role in an R&D team with minimal legacy support.
• Annual company events and team buildings.
• Workout classes (Pilates, volleyball).
• Flexible working hours with remote availability (offices in Vilnius and Kaunas).
• Monthly salary range: €4500–€7000 gross.