Senior .NET Migration Engineer - Remote & Cloud-Ready

N-iX; Kraków; Hybrid; PLN 180,000 - 260,000; Full time

Benefits offered by this job

Flexible working format

Competitive salary

Career growth

Education reimbursement

Team events

Job summary

N-iX is seeking a seasoned .NET Engineer to lead the modernization of a large-scale system in Kraków. You will migrate from .NET Framework 4.8 to .NET 10, move data access to EF Core, and ensure services are portable and container-ready for AWS.

You’ll work with DevOps and DB engineers in a cross-functional Agile team, delivering a phased, production-safe migration with robust unit tests and governance.

Qualifications

• 5+ years of C# and .NET backend development with strong knowledge of ASP.NET and ASP.NET Core.
• Proven hands‑on experience migrating .NET Framework applications to .NET Core / .NET 8, 10 in production.
• Solid experience with EF Core; solid knowledge of DDD, CQRS, and repository patterns in layered .NET architectures.
• Familiarity with Docker multi-stage builds and Linux container fundamentals for .NET applications.
• Proficient with xUnit and Moq for unit testing; comfortable with container-wired test setups.
• Experience with AWS ECS / Fargate and ECR for deploying containerized .NET applications.
• Familiarity with MassTransit and RabbitMQ or Amazon MQ for event-driven messaging.
• Experience with Hangfire or similar background job processing frameworks.
• Proficient in Git and familiar with Agile/SCRUM team processes.

Responsibilities

• Migrate a .NET Framework 4.8 application to .NET 10.
• Migrate EF 6 model to EF Core 8 across bounded contexts, domain-by-domain.
• Identify and replace Windows-only libraries to run on Linux.
• Establish unit test coverage measurement and enforce quality gates in migration pipeline.
• Collaborate with DevOps on Dockerfile authoring, env configuration, and secrets injection.
• Participate in Agile/SCRUM processes, conduct code reviews, document migration decisions.

Skills

C#/.NET

ASP.NET Core

EF Core

Docker

AWS ECS/Fargate

Linux

Unit testing

DDD/CQRS

Git

Agile/SCRUM

Tools

MassTransit

RabbitMQ

Hangfire

Job description

N-iX is seeking a seasoned .NET Engineer to lead the modernization of a large-scale system in Kraków. You will migrate from .NET Framework 4.8 to .NET 10, move data access to EF Core, and ensure services are portable and container-ready for AWS.

You’ll work with DevOps and DB engineers in a cross-functional Agile team, delivering a phased, production-safe migration with robust unit tests and governance.