Backend Software Developer (C#)

About the Position

We are seeking a Backend Software Developer (C#) with 4+ years of experience to join our team in Katowice, Poland. You will lead backend development and manage AWS-based infrastructure.

Responsibilities

• Lead backend development and technical delivery of a cloud-native microservices platform.
• Design, develop, and maintain scalable backend services using C# and.NET.
• Manage AWS-based infrastructure, including ECS, Lambda, Cognito, and supporting services.
• Participate in and coordinate vendor transition and knowledge transfer activities.
• Lead structured codebase handover sessions with the outgoing vendor.
• Own architecture documentation and knowledge transfer workshops.
• Ensure full understanding of all backend services, deployment pipelines, and infrastructure components.
• Develop and maintain Infrastructure as Code using Terraform.
• Build, optimize, and support ETL processes and data pipelines using Python.
• Maintain and improve CI/CD processes using GitHub Actions.
• Collaborate with stakeholders, architects, and development teams to deliver business requirements.
• Ensure platform reliability, security, performance, and maintainability.

Requirements

• Degree in Computer Science, Engineering, or related field.
• 4+ years of backend software development experience.
• 2+ years in a Senior Engineer role.
• Proven hands-on experience working with AWS cloud services in production environments.
• Experience leading technical teams and driving delivery in complex projects.
• Strong understanding of microservices, distributed systems, and cloud-native architecture.
• Experience managing vendor transitions, system onboarding, or large-scale knowledge transfer initiatives is a strong advantage.
• Ability to work effectively in ambiguous environments and quickly gain ownership of existing systems.
• Strong communication and stakeholder management skills.
• Very good knowledge of English and Polish.
• Openness to visit office once a month.

We Offer

• Motivizer Benefits Platform to choose and manage all your benefits in one place. You receive a budget (550 PLN monthly). You can choose medical care package, meal tickets, sports cards (we have Multisport and on preferential terms, we have membership cards to one of the most popular Gyms), cinema tickets, shop vouchers, discounts and many more.
• Language Courses – you'll have access to a multi-language learning platform enabling you to practice your language skills and learn new ones!
• Regular and systematic further training opportunities - both internally and from external providers. We support your ongoing learning and development.
• Cooperation within an internal community is our everyday reality. We have networking events, coding challenges, and company parties for different occasions.
• Healthcare package
• Healthcare package for families
• Leisure package
• Language courses
• Conferences
• Trainings
• Books
• Financial bonus

About the Company

Develop yourself and the digital future – at Reply!

Reply is made up of a network of highly specialised companies, which support leading industrial groups in defining and developing business models to optimise and integrate processes, applications and devices, using new technology and communication paradigms, such as Artificial Intelligence; Big Data; Cloud Computing; Digital Communication; Internet of Things; Mobile and Social Networking.

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Salary: 13 000 - 19 000 PLN Gross (Employment contract) / month

Location: Katowice, Poland

Employment Type: Full-time

Contract type: Employment contract

Work mode: Hybrid

Experience: Senior

Open to Ukrainian candidates

Visa Services

Perks:

• Cold beverages
• Hot beverages
• Lunches
• Integration events

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Apply now and join our team at Reply Polska!