Senior Software Engineer

The Role

Immowelt is hiring a Senior Backend Engineer with strong C# / .NET experience to help build, improve and operate backend services across one of Europe’s leading real-estate platforms.

This is a hands-on product engineering role for someone who enjoys building reliable backend systems, working close to production, and taking ownership beyond just writing code.

You will work on backend services built with C# / .NET and deployed in an AWS environment, contributing to systems that need to be scalable, observable, secure and maintainable.

This role would suit someone who is comfortable with engineering trade-offs, cloud-based service ownership, and working in a platform where technical decisions have real impact for users and teams across multiple European markets.

What you’ll do

• Build, improve and maintain backend services using C# / .NET
• Design clean APIs, service boundaries and integration patterns
• Work with AWS-based services and cloud deployment environments
• Own services beyond development, including reliability, monitoring and production support
• Improve performance, scalability, maintainability and operational visibility
• Work with CI/CD, logging, monitoring and observability tooling
• Collaborate with product, platform and engineering teams across AVIV
• Make pragmatic technical decisions around quality, speed, security and long-term maintainability
• Contribute to the continued modernisation of AVIV’s real-estate marketplace platforms

What we’re looking for

• Strong backend engineering experience with C# and .NET
• Experience building and operating production backend services
• Good understanding of APIs, microservices, distributed systems and service design
• Practical exposure to AWS or another major cloud environment
• Experience with CI/CD, monitoring, logging and incident investigation
• Comfortable working in a product engineering environment, not just a ticket-delivery setup
• Strong ownership mindset and the ability to work through ambiguity
• Good communication skills and a collaborative approach to engineering

Useful experience

• AWS services in a backend engineering context
• Docker, Kubernetes or containerised environments
• Event-driven systems, messaging or streaming platforms
• Observability tools such as Datadog, Grafana, Prometheus or similar
• Experience improving legacy systems without over-engineering
• Experience working in high-scale marketplace, platform or SaaS environments

Interview Process

We run a structured interview process designed to assess both technical depth and how you approach engineering problems in a real product environment.

• Recruiter screening, 30 minutes
• A first conversation to discuss your background, motivation, role fit, location, expectations and any practical questions.
• Karat technical screen, 60 minutes
• A live technical assessment covering baseline coding, problem-solving and relevant engineering fundamentals.
• Coding interview, 60 minutes
• A deeper live coding and language-focused interview with AVIV engineers, covering C# / .NET proficiency, problem-solving approach and practical backend depth.
• System design and final interview, 90 minutes
• A combined technical and team conversation covering architecture thinking, trade-offs, communication, motivation and alignment with the team.

Why Immowelt / AVIV Group

Immowelt is part of AVIV Group, one of Europe’s leading digital real-estate marketplace groups, operating brands used by millions of people across Europe.

This is not just classifieds. AVIV’s platforms support major life decisions: finding a home, moving city, starting a new chapter.

The engineering environment combines scale, product impact and meaningful technical complexity. Teams work on systems that need to be reliable, fast and trusted across multiple European markets.

You will join at a point where the platform is evolving, engineering ownership is increasing, and strong backend engineers can have a visible impact on how systems are built, operated and improved long term.

Equal Opportunities

Immowelt and AVIV Group are committed to building an inclusive environment where people from all backgrounds can do their best work. We welcome applications from candidates with different experiences, perspectives and career paths.