Senior Sofware Engineer .NET/Backend

CQUE; Kraków; Hybrid; PLN 190,000 - 270,000; Full time

Job summary

CQUE is seeking a Senior Backend Engineer to join our international engineering team building enterprise SaaS products. You’ll design, develop and maintain scalable backend services with C#/.NET 6+, implement microservices and RESTful APIs, and work with AWS in a cloud-native environment.

You will collaborate with Product Managers, Architects and Frontend Engineers, contribute to architectural decisions, and help raise engineering practices, testing, and deployment automation across the stack.

Qualifications

• 5+ years of professional backend software development experience.
• Experience with enterprise web applications or cloud-based SaaS platforms.
• Strong understanding of the full SDLC.
• Strong experience with C# / .NET 6+; ASP.NET MVC/Blazor.
• Entity Framework; SQL Server.
• RESTful APIs; Microservices; Distributed systems.
• Commercial experience with AWS and cloud-native development.
• Strong understanding of system design, scalability and performance engineering.

Responsibilities

• Design, develop and maintain high-performance backend services using C# and .NET
• Build secure and reliable RESTful APIs
• Design and implement microservice architectures
• Develop cloud-native applications using AWS
• Improve system performance, reliability, scalability and security
• Collaborate with Product Managers, Architects and Frontend Engineers
• Contribute to architecture discussions and technical design
• Participate in code reviews and promote engineering best practices
• Build automated unit, integration and end-to-end tests
• Contribute to CI/CD pipelines and deployment automation
• Investigate production issues and drive sustainable technical improvements
• Identify technical debt and help improve long-term system maintainability

Skills

C#

.NET 6+

ASP.NET MVC/Blazor

RESTful APIs

Microservices

SQL Server

Distributed systems

Cloud AWS

Event-driven architecture

Tools

Docker

Kubernetes

Terraform

GitHub Actions

TeamCity

Elasticsearch

Job description

Working model: Hybrid - 4 days (in-office)

Level: Senior

Are you a Senior Backend Engineer passionate about building scalable, cloud-native software?

We’re looking for an experienced Senior Software Engineer - Backend (.NET) to join a high-performing international engineering team building enterprise SaaS products used by customers across global markets.

You’ll work with C#, .NET, ASP.NET Core, microservices and AWS, helping design and develop highly scalable, resilient and secure backend platforms.

What You'll Be Doing:

• Design, develop and maintain high-performance backend services using C# and .NET
• Build secure and reliable RESTful APIs
• Design and implement microservice architectures
• Develop cloud-native applications using AWS
• Improve system performance, reliability, scalability and security
• Collaborate with Product Managers, Architects and Frontend Engineers
• Contribute to architecture discussions and technical design
• Participate in code reviews and promote engineering best practices
• Build automated unit, integration and end-to-end tests
• Contribute to CI/CD pipelines and deployment automation
• Investigate production issues and drive sustainable technical improvements
• Identify technical debt and help improve long-term system maintainability

What We're Looking For:

• 5+ years of professional backend software development experience
• Experience with enterprise web applications or cloud-based SaaS platforms
• Strong understanding of the full SDLC
• Strong experience with:C# / .NET 6+
• ASP.NET MVC / Blazor
• Entity Framework
• SQL Server
• RESTful APIs
• Microservices
• Distributed systems
• Event-driven architecture
• Commercial experience with AWS and cloud-native development
• Strong understanding of system design, scalability, distributed computing and performance engineering

Nice to Have:Experience with technologies such as:AWS: Lambda, API Gateway, DynamoDB, RDS / SQL Server, ElasticsearchDevOps: Terraform, GitHub Actions, TeamCity, Docker, Kubernetes, CI/CDObservability: Monitoring, logging, metrics and distributed tracingArchitecture: Serverless, high-volume distributed systems and backend services supporting React applications

What We Value:

We’re looking for an engineer who brings strong communication and collaboration skills, takes ownership, enjoys solving complex problems and is committed to continuous learning and modern engineering practices.

You’ll join an international, collaborative engineering environment with opportunities to influence technical direction and work with modern cloud-native architectures and distributed systems.