Mid/Senior .Net Developer

About the Project

We are looking for a Mid/Senior .Net Developers who will be working on a large, multi-tenant HCM system that supports HR, Recruitment, and Admin modules. You will join one of several Scrum teams responsible for developing, maintaining, and modernizing a .NET-based solution currently being upgraded to .NET 8. The environment is dynamic and in transition, requiring a proactive, independent approach and strong collaboration skills.

Tech: .Net 4.8/.Net 8, MS-SQL, Entity Framework, Redis, RabbitMQ, Bitbucket, Azure DevOps

Duration of the project: long-term

Salary range: Mid: 140-160 PLN net/h; Senior: 160-180 PLN net/h

Work Mode: remote 

Job Responsibilities

• Design, develop, and maintain backend services using .NET 6+ (migration to .NET 8 in progress)

• Work with Entity Framework, MS SQL, and Redis for data access, caching, and performance optimization

• Contribute to system modernization - moving from a monolithic architecture toward a modular/microservices model

• Collaborate with frontend developers (Angular), QA, DevOps, and Product teams in a Scrum environment

• Participate in code reviews, ensure high-quality, maintainable, and testable code

• Support CI/CD processes and contribute to the introduction of containerization

• Troubleshoot and improve performance of multi-tenant databases and distributed systems

• Write unit tests (xUnit) 

• Participate in knowledge transfer and share best practices across teams

Expectations

• Min. 4 years of experience on a similar position

• Proficiency in .NET 6+ and strong knowledge of C#, including advanced language features

• Experience with Entity Framework, including database migrations and query optimization

• Strong understanding of MS SQL Server, especially in multi-tenant environments and performance tuning

• Hands-on experience with REST APIs; familiarity with gRPC or GraphQL

• Practical knowledge of Git and branching strategies (GitFlow, pull requests)

• Experience using Bitbucket, Azure DevOps, or similar tools for CI/CD

• Familiarity with microservices, modularization, and domain-driven design principles

• Understanding of software security practices (access control, encryption, secure data handling)

• Knowledge of Redis, ElasticSearch, and RabbitMQ for caching, search, and messaging

• Familiarity with Docker and containerization concepts (hands-on experience is an advantage)

• Experience writing unit tests (xUnit or similar frameworks)

• English on an advanced level (min. B2)

• Familiarity with NoSQL databases is an advantage

We offer

• Ongoing support from a dedicated agent, taking care of your project continuity, client contact, necessary formalities, work comfort and development

• Consultant Development Program – advice on growth planning based on the latest trends and market needs in IT, including consultations with agents and growth mentors

• Access to 7N Learning & Development – a development and educational platform with webinars, a library of articles and industry reports, and regular invitations to one-time and recurring development events – technical, business, and lifestyle

• Spectacular integration events, both for you (e.g., annual Kick-Off trip, Christmas parties, or Summer Olympics sports events) and for your loved ones (e.g., family picnics, movie premieres)

• Professional development not only during the project – you can get involved in knowledge transfer to others within the 7N Services offering directed at 7N clients

• Relationships and access to the knowledge of the most experienced IT experts in the market – the average professional tenure of our consultants in Poland is over 10 years

• A complete benefits package, including funding for medical care, life insurance, sports cards for you and your loved ones, as well as discounts in stores in Poland and abroad

About 7N

Constantly searching for projects, difficult rate negotiations, lack of development support – sounds familiar? At 7N, you gain not only stability of contracts but also the personal involvement of a dedicated agent who ensures your professional comfort and continuous access to development initiatives. 

Our mission is to provide stable and rewarding collaborations that drive your success as an IT expert and the success of our clients. We build long-lasting relationships based on Scandinavian values and 30 years of experience creating IT solutions for over 200 organizations.