Senior .Net Backend Engineer

Location: Ukraine

Department: Lebara: Omni Team

N-iX is looking for a talented Senior .Net Engineer to join our team!

Our client is one of Europe's fastest-growing mobile companies with 6 million active customers, 1,000 employees worldwide, and operations in five countries. The client is using the mobile virtual network operator business model. We are looking for a Senior .NET Engineer who combines strong technical expertise with a product mindset, proactive problem-solving, and end-to-end ownership of delivery.

Responsibilities:

• Take end-to-end ownership of features and services, from requirements clarification and technical design through implementation, testing, deployment, and production support.
• Deliver reliable, scalable, and maintainable back-end solutions using modern .NET technologies and engineering best practices
• Understand business requirements, product objectives, and customer impact to make pragmatic technical decisions and deliver business value
• Collaborate closely with Product Owners, Business Analysts, QA Engineers, DevOps, Support Engineers, Architects, Infrastructure and DB Engineers, and other teams to ensure successful delivery
• Proactively identify and address technical risks, dependencies, blockers, and potential delivery challenges
• Contribute to system design, architectural decisions, technical improvements, and ongoing platform modernisation
• Take ownership of production issues, troubleshooting, root-cause analysis, and improvements to system reliability and performance
• Ensure high engineering quality through code reviews, automated testing, observability, and continuous improvement
• Confidently communicate in a multinational environment, communication is in English.
• Design, build, and maintain performant, efficient, reusable, and reliable code
• Translate business logic into code and automate business processes
• Support and mentor other engineers, share knowledge, and promote engineering best practices

Requirements:

• 6+ years of commercial .NET development in Microservice environment
• Strong knowledge of modern .NET (8/9 or later)
• Web API, ASP.NET Core, Microservices
• Strong experience with SQL, MS SQL Server, Entity Framework, and database performance optimisation
• Good understanding of Docker, Kubernetes, and containerised application environments
• Solid understanding of software architecture, microservices, design patterns, SOLID principles, and clean code practices
• Hands-on experience with Microsoft Azure Cloud
• Experience with Messaging or Evening (ServiceBus, RabbitMQ, EventHub, Kafka,. Etc.)
• Experience designing and integrating REST APIs, SOAP and third-party services.
• Hands-on experience with serverless architectures and cloud functions (Azure Functions, AWS Lambda)
• Experience with automated testing, CI/CD practices, and production troubleshooting
• Strong problem-solving skills, proactive communication, and the ability to identify risks and propose solutions
• Being result-oriented, ability to get things done
• Excellent verbal and written English communication skills, with the ability to confidently lead technical discussions, articulate complex topics, challenge decisions constructively, and communicate effectively with both technical and non-technical stakeholders

Would be a plus:

• Production experience with durable-execution, stateful distributed-systems platform (Microsoft Orleans, Temporal, Azure Durable Task Framework, Akka, Dapr Actors, Cadence, Netflix Conductor, Erlang/OTP)
• Day-to-day responsibilities involves dealing with long-running workflows, stateful coordination, distributed execution, failure recovery, retries, idempotency in production
• Serious experience in Event Driven Architecture
• Experience with microservice practices, i.e. Service mesh, Blue/Green deployments, ArgoCD, etc.
• Experience with Stored procedures in MS SQL
• Experience with .Net Native AOT
• Experience with Monitoring (Azure Application Insights, Open Telemetry, etc.)
• Azure LogicApps, API Apps, AKS, Redis
• Experience integrating with Microsoft Dynamics CRM or similar enterprise systems
• Experience working with high-availability, business-critical, or transaction-processing systems