Senior Backend Engineer (.NET / C# Microservices)

We are looking for a Senior Backend Engineer to design, develop, and optimize high-performance backend services that power mission-critical healthcare and procurement platforms. In this role, you will build scalable .NET 8 microservices, develop secure APIs, implement event-driven architectures using Kafka, and contribute to resilient, observable, and highly available distributed systems.

You will collaborate with cross-functional teams to deliver reliable backend solutions while driving engineering best practices around architecture, performance, security, and software quality.

Key Responsibilities

• Design, develop, and maintain scalable backend services using .NET 8 and ASP.NET Core.
• Build and maintain RESTful APIs, GraphQL endpoints, and background processing services.
• Develop event-driven microservices using Kafka, including producers, consumers, retry mechanisms, idempotency, and Dead Letter Queue (DLQ) strategies.
• Design software following Domain-Driven Design (DDD) and Clean Architecture principles.
• Develop and optimize data access using Entity Framework Core and SQL Server, including indexing, query optimization, transactions, and database migrations.
• Implement distributed systems patterns including Outbox/Inbox, correlation IDs, distributed tracing, and resilient communication.
• Integrate backend services with Ultimus BPM for workflow automation and business process orchestration.
• Improve application observability using Serilog, Elastic Stack (Elasticsearch/Kibana), metrics, and distributed tracing.
• Ensure secure development practices by implementing API security, rate limiting, input validation, and OWASP recommendations.
• Write and maintain automated unit, integration, and contract tests while participating in peer code reviews.
• Deploy and support containerized applications running on on-premises Kubernetes environments.
• Work closely with Product Managers, DevOps Engineers, QA Engineers, and Frontend Developers to deliver high-quality software.

Required Qualifications

• Bachelor's degree in Computer Science, Software Engineering, or a related field.
• Minimum 5 years of backend software development experience.
• At least 2 years of hands-on experience with ASP.NET Core/.NET Core in production environments.
• Strong expertise in C#, .NET 8, and ASP.NET Core.
• Proven experience building and maintaining Microservices architectures.
• Strong hands-on experience with Kafka, including topics, partitions, consumer groups, offsets, retries, and idempotent processing.
• Strong SQL Server knowledge, including indexing, query execution plans, transactions, and performance optimization.
• Practical experience with Entity Framework Core.
• Experience with Docker and Kubernetes (on-premises environments preferred).
• Experience implementing distributed systems patterns such as Outbox/Inbox, Circuit Breaker, Saga, Retry, Bulkhead, and Idempotency.
• Experience with logging, monitoring, and observability tools such as Serilog, Elastic/Kibana, and distributed tracing.
• Experience securing APIs using authentication, authorization, secrets management, and OWASP best practices.
• Experience working with CI/CD pipelines using Azure DevOps, Git, and SonarQube.
• Excellent communication, collaboration, and documentation skills.

Nice to Have

• Ultimus BPM integration experience.
• Redis.
• Nginx.
• GraphQL.
• SignalR.
• Event Sourcing.
• CQRS.
• Performance engineering and cost optimization experience.