Senior .NET Developer with AWS and React (f/m/x)

Sii Poland; Województwo pomorskie; On-site; PLN 180,000 - 260,000; Full time

Benefits offered by this job

Centre of internal trainings

Profit sharing

Medical care

Job summary

Sii Poland is seeking a Senior .NET Developer to help transform a data‑driven analytics platform in the cloud. You will design scalable architectures and modernize legacy components, applying SOA concepts and collaborating with a globally distributed team to deliver robust software solutions.

The role emphasizes high‑quality coding standards, continuous improvement, and close teamwork with engineers, analysts, and QA to meet business needs. English proficiency is required.

Qualifications

• 5+ years in software development with a strong .NET focus.
• Expertise in designing and implementing web services.
• Experience with AWS and cloud environments
• Hands-on mastery of Redux and Context API in React apps
• Solid understanding of software design principles
• Advanced level of English

Responsibilities

• Contribute to cloud transformation of a data-intensive analytical platform.
• Design scalable architectures and modernize legacy components.
• Propose and implement modern frameworks and architectural improvements
• Apply SOA concepts in software design and development
• Provide timely support to platform users and resolve issues
• Collaborate with engineers, analysts and QA to meet business needs

Skills

.NET

English (Advanced)

Cloud experience

Tools

AWS

React

Redux

Context API

Web services

Job description

We are looking for a Senior .NET Developer to join our team and contribute to the cloud transformation of a data-intensive analytical platform. In this role, you will collaborate with innovative and diverse professionals from around the world, designing scalable architectures and modernizing legacy components to ensure performance and reliability.

Your tasks

• Contributing to the cloud transformation of a data-intensive analytical platform by designing scalable architectures and modernizing legacy components
• Ensuring continuous technological evolution of the product by proposing and implementing modern frameworks and architectural improvements
• Applying Service Oriented Architecture (SOA) concepts in software design and development
• Providing timely and courteous support to platform users, ensuring issues are understood, analyzed, and resolved promptly
• Collaborating closely with a team of software engineers, analysts, and quality engineers to design and build software solutions that meet business needs
• Adhering to team design and coding procedures and standards

Requirements

• Minimum 5 years of experience in software development with a strong focus on .NET technologies
• Deep expertise in designing and implementing web services
• Practical experience with AWS and cloud environments
• Hands‑on mastery of Redux and Context API in React applications
• Strong understanding of software design principles and best practices
• Advanced level of English

Nice to have

• Experience with C#

Job no. JOB-KF82T

Sii ensures that all hiring decisions are made solely on the basis of qualifications and competence. We are committed to equal and fair treatment of all, regardless of legally protected characteristics. At Sii, we promote a diverse and inclusive work environment, in full compliance with applicable anti-discrimination laws.

Benefits For You

• Great Place to Work
• Solid financial situation
• Contracts with the biggest brands
• Centre of internal trainings
• Many experts you can learn from
• Open and accessible management team
• Profit sharing
• Passion Sponsorship program
• Regular integration events and trips
• Comfortable and well‑equipped offices
• MySii app
• Medical care