Senior .NET Developer

Our requirements

• Minimum 5+ years of professional experience developing applications using the .NET ecosystem (C#, .NET Core / .NET 5+), including designing, implementing and maintaining backend services.
• Strong object-oriented design and programming skills, with solid knowledge of design patterns, SOLID principles, and clean architecture.
• Proven experience building and consuming RESTful APIs, Web APIs, and gRPC services; knowledge of API versioning, documentation (Swagger/OpenAPI) and authentication/authorization mechanisms (OAuth2, JWT, OpenID Connect).
• Deep understanding of asynchronous programming, multithreading and concurrency in .NET (async/await, Task Parallel Library, thread-safety).
• Hands-on experience with relational databases (SQL Server, PostgreSQL) and ORM tools (Entity Framework Core, Dapper); ability to design efficient schemas, write optimized queries and handle migrations.
• Experience with NoSQL/datastore technologies (e.g., MongoDB, Redis) and when to apply them.
• Familiarity with cloud platforms and services (Azure, AWS, or GCP), including deploying .NET applications, serverless functions, container services and cloud-native patterns.
• Proficiency with containerization and orchestration: Docker, Kubernetes (or knowledge of managed container services).
• Experience with CI/CD pipelines, build automation and release management (Azure DevOps, GitHub Actions, Jenkins, TeamCity, etc.).
• Strong testing mindset: unit testing, integration testing, test automation frameworks (xUnit, NUnit, Moq) and experience enabling testable codebases.
• Knowledge of logging, monitoring and diagnostics tools (Serilog, Application Insights, Prometheus, Grafana) and ability to troubleshoot production issues.
• Familiarity with frontend technologies and SPA frameworks (Angular, React, or Vue) enough to collaborate with frontend teams and design end-to-end solutions.
• Experience mentoring junior developers, conducting code reviews, and driving technical decisions and best practices across teams.
• Excellent problem-solving, communication and collaboration skills; ability to work in Agile/Scrum environments and participate in planning, estimation and backlog refinement.
• Security-aware development: secure coding practices, threat modeling, data protection (encryption, secure storage), and familiarity with common vulnerabilities (OWASP).
• Performance tuning and scalability experience: profiling .NET applications, optimizing memory and CPU usage, caching strategies and load testing.
• Experience with message brokers and event-driven architectures (RabbitMQ, Kafka, Azure Service Bus) and implementing pub/sub or CQRS patterns.
• Familiarity with infrastructure-as-code practices and tools (Terraform, ARM templates, Bicep) is a plus.
• Bachelor’s degree in Computer Science or related field, or equivalent practical experience; willingness to continuously learn and adopt new technologies.

Your responsibilities

This is how we organize our work

This is how we work on a project

• Clean Code
• architect / technical leader support

We create open source

What we offer

• Ability to define your development path
• Mentoring (with the use of practical tasks)
• An informal but productive work environment

Development opportunities we offer

• mentoring
• substantive support from technological leaders
• technical knowledge exchange within the company
• time for development of your ideas

Benefits

• remote work opportunities
• flexible working time
• integration events
• opportunity to obtain permits and licenses

Recruitment stages

• 1.
  About 30 minute HR interview
• 2.
  About 1h technical interview
• 3.
  Call with a customer (optional)

PROGNETICS SPÓŁKA Z OGRANICZONĄ ODPOWIEDZIALNOŚCIĄ