Senior Software Engineer (Team Contract)

Sunweb Group; Rotterdam; Hybrid; EUR 65,000 - 80,000; Full time

Benefits offered by this job

Hybrid work

Holiday allowance

Office equipment

Career development plan

Coaching

Home/travel allowances

Job summary

Sunweb Group in Rotterdam is seeking a Senior Software Engineer to help build a new internal contracting application, replacing the legacy system. You will join Team Dalyan initially, with growth into a dedicated Contracting Team, in a hybrid Rotterdam office.

Start date December 2026 and fulltime employment. You will design and implement cloud-native solutions using C#, .NET, and Azure, build user-friendly React interfaces for internal users, and model data with SQL.

Qualifications

• Five+ years of professional C#/.NET experience.
• Experience building cloud-native apps on Azure.
• Strong SQL and data-modelling skills.
• Clear communication and ownership mindset.

Responsibilities

• Design and build new contract app for suppliers.
• Develop cloud-native solutions using C#, .NET, and Azure.
• Build internal React applications.
• Replace legacy app with scalable modern solution.
• Contribute to system design and data modelling.
• Develop reliable integrations with SQL databases.
• Apply automated testing, CI/CD and DevOps practices.
• Communicate decisions, progress, risks and dependencies clearly.
• Take ownership from design to delivery and production.
• Collaborate with contractors, suppliers and internal teams.
• Use GitHub Copilot and other tools to boost productivity.

Skills

C#

.NET

Cloud architecture

SQL

React

English communication

Tools

Azure

GitHub Copilot

CI/CD

Job description

Build the technology behind our holiday contracts

At Sunweb Group, we are developing a new internal application for creating and managing contracts with our suppliers and contractors.

As our Senior Software Engineer, you will help build this application from the ground up and replace an existing legacy solution with a modern, future-ready platform. You will have the opportunity to shape both the technical foundation and the way the new team works.

This is a new team with an initial size of approximately two to three engineers.

You will first be onboarded within Team Dalyan, working in a group of around five colleagues. Once the new Contracting Team is established, it will separate into its own team with a dedicated scope and responsibilities.

Location: Rotterdam Sunweb Group office (Hybrid)

Start date: December 2026

Availability : Fulltime

What you'll do

• Design and build a new application for creating and maintaining supplier contracts.
• Develop cloud-native solutions using C#, .NET and Microsoft Azure.
• Build user-friendly React applications for internal users.
• Help replace a legacy application with a scalable and maintainable modern solution.
• Contribute to system design, architecture and data-modelling decisions.
• Develop reliable integrations and work with SQL-based data.
• Apply automated testing, CI/CD and DevOps practices throughout the development lifecycle.
• Communicate technical decisions, progress, risks and dependencies clearly.
• Take ownership from initial design through delivery and production.
• Collaborate with contractors, suppliers and internal teams that depend on accurate contracting information.
• Use GitHub Copilot and other supporting tools to improve productivity and software quality.

Our tech stack

• C# - .NET - Microsoft Azure - SQL - React - GitHub - GitHub Copilot - CI/CD - Automated Testing - DevOps

What you bring

• At least five years of professional experience with C# and .NET.
• Experience building cloud-native applications on Microsoft Azure.
• Strong SQL and data-modelling skills.
• Solid system-design experience.
• The ability to apply clean-architecture principles pragmatically.
• Experience developing React applications, preferably for internal tools.
• Experience with CI/CD, automated testing and DevOps practices.
• Experience modernising or replacing legacy systems.
• Clear communication skills and the ability to make progress, risks and dependencies visible.
• An ownership mindset: you follow work through from idea to delivery.
• A pragmatic approach that balances engineering quality with delivery needs.
• Strong stakeholder communication skills in English (Dutch is a big plus).

What we offer

• Yearly gross salary between 65K and 80K, excluding 8% holiday allowance).
• 25 holidays + 6 ATV days, based on fulltime employment. Please note: ATV days do not apply to part-time contracts.
• Enjoy up to 20% off when booking with our brands for you, your family, and your friends.
• As an international company we support a hybrid way of working. We provide you with office furniture and IT equipment.
• A personalized Reflect & Develop Plan to support your career growth.
• Benefit from coaching sessions designed to support your well-being.
• Receive work-from-home and travel allowances to ease your daily routine.

About Sunweb Group

Sunweb Group is one of Europe's largest online travel platforms, with over 1.3 million customers annually. We operate in 8 international markets with 500+ colleagues across Europe. We combine scale with a fast-moving, ownership-driven culture where teams are trusted to build and improve continuously.

Why this role is interesting

Build a new application instead of only maintaining an existing system.

Influence technical decisions and architecture from an early stage.

Help shape a new engineering team and its ways of working.

Modernise a business-critical part of the Sunweb ecosystem.

Work with a modern Microsoft-based technology stack.

Take genuine ownership of a product with clear internal impact.

Join an international organisation that combines technology with unforgettable holiday experiences.

Application deadline: 23 October

Sunweb Group is an equal opportunity employer, which means we do not discriminate in any way.

We celebrate diversity and are committed to creating an inclusive and safe environment for all employees.