Senior .NET Developer: Cloud-Driven Platform & AWS Expert

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

Benefits offered by this job

Great Place to Work

Solid financial situation

Contracts with the biggest brands

Centre of internal trainings

Profit sharing

Regular integration events and trips

Medical care

Job summary

Sii Poland is seeking a Senior .NET Developer to join our team and help transform a data‑driven analytical platform in the cloud. You will design scalable architectures and modernize legacy components to ensure performance and reliability.

You will collaborate with diverse professionals worldwide, apply SOA concepts, and contribute to ongoing platform evolution. Strong .NET, web services, AWS, and React/Redux experience are essential, as is excellent written and spoken English.

Qualifications

• 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.

Responsibilities

• 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.

Skills

.NET

Web services

AWS

Redux

Context API

Software design principles

English proficiency

C#

Job description

Sii Poland is seeking a Senior .NET Developer to join our team and help transform a data‑driven analytical platform in the cloud. You will design scalable architectures and modernize legacy components to ensure performance and reliability.

You will collaborate with diverse professionals worldwide, apply SOA concepts, and contribute to ongoing platform evolution. Strong .NET, web services, AWS, and React/Redux experience are essential, as is excellent written and spoken English.