Senior Backend Engineer – Mobile (Azure/.NET)

Sunweb Group; Rotterdam; Hybrid; EUR 60,000 - 73,000; Full time

Benefits offered by this job

Hybrid work model

Rotterdam office

Travel allowances

Equipment provided

Career development plan

Coaching sessions

Work-from-home allowances

Job summary

Sunweb Group is seeking a Senior Backend Engineer – Mobile to own the backend services behind our native apps. You will design, build and run REST APIs and cloud-native .NET services used by Sunweb Group apps, shielding mobile clients from travel-domain complexity.

Based in the Rotterdam area with flexible hybrid work, you will collaborate with mobile engineers, product owners and architects, mentor teammates, and raise the bar on testing, CI/CD, observability and security.

Qualifications

• Minimum 5 years backend experience with modern C# and .NET.
• Design REST APIs for mobile clients with versioning and backward compatibility.
• Model complex travel-domain data (bookings, customers, payments).
• Strong knowledge of cloud-native architectures on Azure.
• Fluent English and strong stakeholder communication.

Responsibilities

• Design, build and operate cloud-native .NET services and REST APIs on Azure.
• Own critical mobile-backend capabilities end to end.
• Define and enforce testing, CI/CD, observability and security standards.
• Collaborate with mobile engineers, product owners and architects.
• Mentor teammates and shape backend practices in a mobile-first team.
• Ensure backward compatibility across app versions.

Skills

5+ years C#/.NET

REST API design

API versioning

Domain modelling

Azure cloud

SQL modelling

CI/CD & tests

Production monitoring

English proficiency

Stakeholder communication

Ownership & go-to backend

Tools

Azure

Cosmos DB

Service Bus

New Relic

GitHub Actions

Azure Functions

Job description

Sunweb Group is seeking a Senior Backend Engineer – Mobile to own the backend services behind our native apps. You will design, build and run REST APIs and cloud-native .NET services used by Sunweb Group apps, shielding mobile clients from travel-domain complexity.

Based in the Rotterdam area with flexible hybrid work, you will collaborate with mobile engineers, product owners and architects, mentor teammates, and raise the bar on testing, CI/CD, observability and security.