Senior Full-Stack Engineer (.NET / C#, Backend-Focused), Hybrid: Warsaw, Poland

Eastern Peak; Województwo mazowieckie; Hybrid; PLN 180,000 - 260,000; Full time

Job summary

Eastern Peak in Warsaw is seeking a Senior Full-Stack Engineer with a strong backend core to design, build, and operate backend services in C# / .NET for a large-scale, multi-tenant cloud platform.

You will work across Kubernetes, cloud networking, databases, and Redis, own features end to end, contribute to frontend when needed, and collaborate daily with Israel-based engineers as part of a hybrid team.

Qualifications

• 5+ years of hands-on software engineering in a product environment.
• 5+ years of experience with .NET (C#).
• 3+ years building large-scale backend systems; strong backend design patterns.

Responsibilities

• Design, build, and operate backend services in C# / .NET that power the platform at scale.
• Contribute to backend architecture: data access, performance, and scalability.
• Work hands-on with cloud infrastructure: Kubernetes, VMs, cloud networking, databases, Redis.
• Own features end to end from design through deployment and production; contribute to frontend when needed.
• Use AI-assisted development tools to speed up development, debugging, and code reviews.
• Collaborate with the team through design discussions, code reviews, and shared delivery ownership.

Skills

5+ years industry experience

5+ years .NET (C#)

3+ years backend architectures

1+ years frontend experience

English communication

team collaboration in hybrid setup

Tools

Kubernetes

VMs

Cloud networking

Redis

Databases

Job description

Date published: 26.10.2026

Location:

Warsaw

Position:

.NET

Level:

Senior

Department:

We are looking for a Senior Full-Stack Engineer with a strong backend core to join the team behind a flagship visual AI testing platform, built by a global leader in AI-powered test automation and used by engineering teams at some of the world’s largest companies.

This role involves designing, building, and operating backend services in C# / .NET for a large-scale, multi-tenant system running in the cloud, with hands-on work across Kubernetes, cloud networking, databases, and Redis. You’ll own features end to end, contribute to the frontend where needed, and collaborate daily with the client’s engineering group in Israel as an integrated member of a hybrid team.

Key responsibilities

• Design, build, and operate backend services in C# / .NET that power the platform at scale.
• Contribute to backend architecture: service design, data access, performance, and scalability.
• Work hands-on with cloud infrastructure, including Kubernetes, VMs, cloud networking, databases, and Redis.
• Own features end to end, from design through deployment and production, and contribute to the frontend where needed.
• Use AI-assisted development tools to speed up development, debugging, and code reviews.
• Collaborate closely with the team through design discussions, code reviews, and shared ownership of delivery.

Requirements

• 5+ years of hands-on industry experience as a software engineer in a product environment.
• 5+ years of experience with .NET (C#).
• 3+ years of experience building large-scale backend systems, with a solid grasp of backend architectures and design patterns.
• 1+ years of experience in a full-stack or frontend role, or with frontend technologies.
• Hands-on experience with cloud infrastructure: Kubernetes, VMs, cloud networking, databases, Redis, or similar.
• Proven experience working in hybrid or extended teams, collaborating day to day with engineers in another country.
• Hands-on experience using AI-assisted development tools in your daily workflow to accelerate development.
• Excellent written and spoken English, with clear, confident verbal communication.
• A true team player who communicates openly and takes shared ownership of results.
• Based in Warsaw and able to work from the office 3 days per week.

Will be a plus:

• DevOps experience (CI/CD, infrastructure as code, monitoring). Hands-on experience with AI-assisted development tools.

About Eastern Peak

We are a technology provider of custom hardware and software development solutions and digital transformation consulting services.

We help our clients adapt and evolve in the face of disruptive new technologies, dynamic global markets and rapidly changing regulatory environments. We do it by modernizing their legacy systems, automating business processes and creating the technological foundation to withstand and embrace continuous change.

We develop and deploy unique data analytics capabilities across their infrastructure and introduce competitive advantages by utilizing the advances in technology such as IoT, AI, Cloud, Big Data, AR/VR and others.