Full Stack Developer

Hays IT Contracting is a cooperation based on B2B rules. We connect IT specialists with the most interesting, technological projects on the market.

Join the group of 500 satisfied Contractors working for Hays’ clients!

For our Client we are currently looking for Candidates for the position of:

Senior Full Stack Developer (.NET, React, Middleware)

Location: Warsaw

Branch: media (an American company)

Job type: B2B (with Hays Poland)

Length: long-term

Rate: 140-160 PLN/h net

Start date: ASAP / 1 month

Working hours: business hours, with occasional meetings during US working hours

Working model: hybrid 2/3 (TBC)

What will you do:

1. Core Development & Integration

·       Integration Workflows: Designing and implementing integration flows and automation tasks using iPaaS or workflow platforms (e.g., Workato, Power Automate) to support data exchange between business systems.

·       Backend Development: Developing and enhancing backend components and services in C# /.NET, focusing on application logic, data processing, and communication within the project scope.

·       Internal Tools Support: Implementing and maintaining internal tools, dashboards, or auxiliary interfaces in React to support data visibility and integration monitoring.

·       Database Engineering: Creating and optimizing MS SQL queries and stored procedures to support performance, data accuracy, and operational requirements in assigned technical tasks.

2. Technical Collaboration

·       Knowledge Exchange: Cooperating with other technical team members on problem solving and information sharing related to backend topics, API usage, or database practices as part of ongoing project work.

·       Code Review Participation: Participating in code reviews by providing technical feedback to ensure consistency, maintainability, and alignment with established project guidelines.

·       Modernization & Refactoring: Executing modernization tasks, including improving or refactoring existing components and codebases based on technical specifications and project requirements.

3. Security & Quality Assurance

·       Security Implementation: Applying established security mechanisms—such as OAuth, JWT, and data encryption—within integration and communication processes, according to project needs.

·       Automated Testing: Developing automated tests (e.g., xUnit, NUnit, Jest) to support service stability, detect changes in data or external systems, and improve overall solution reliability.

What we expect from you:

·       Minimum 5-6 years of experience in C# /.NET programming

·       Some frontend exposure (React) beneficial but not core

·       Focus on APIs, system integrations, and middleware (e.g. Workato, Power Automate or similar)

·       Experience working across distributed systems and data flows between platforms

·       Comfortable with SQL and data transformation

·       Able to mentor junior developers and contribute to code quality and best practices

·       Experience with cloud environments (AWS preferred)

·       Knowledge of English on B2/C1 level

What will you get:

·       Competitive salary

·       Standard benefits - preferential rates for LuxMed and Multisport packages

·       When you choose to work via Hays, you also get the opportunity to work for many of Hays' other leading clients in the future

What will the recruitment process look like:

1.     Your CV will be verified by Hays Recruiter

2.     Recruiter will contact you by phone - a 15-minute conversation about the project and your experience

3.     Technical conversation with the client – 2 online meetings

4.     Offer

5.     Welcome to the project!

Hays Poland sp. z o.o. jest agencją zatrudnienia zarejestrowaną w rejestrze prowadzonym przez Marszałka Województwa Mazowieckiego pod numerem 361.