Senior Software Engineer (Booking and Search domain)

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

Benefits offered by this job

Holiday allowance

Hybrid work model

Brand booking discount 20%

Office furniture provided

Reflect & Develop Plan

Coaching sessions

Work-from-home and travel allowances

Job summary

Sunweb Group in Rotterdam is seeking a Senior Software Engineer to own the Booking and Search domain, shaping how customers find and book holidays. You’ll influence architecture, scale systems and mentor teammates in a small, autonomous Agile team.

You’ll work Hybrid from the Rotterdam office with start December 2026, bringing 5+ years of C#/.NET experience, Azure cloud deployments and a passion for clean architecture and pragmatic engineering. The role offers growth and international impact.

Qualifications

• 5+ years of experience with C# and .NET.
• Experience building cloud-native applications on Azure.
• Strong knowledge of SQL and data modelling.
• Solid understanding of system design and clean architecture.
• Experience with CI/CD, automated testing and DevOps practices.
• Experience with legacy systems and modernisation.
• Ownership mindset and drive to improve systems and processes.
• Strong stakeholder communication skills in English (Dutch is a big plus).
• Experience mentoring others and shaping the technical vision and direction of a team.
• Experience with Kubernetes is a big plus.

Responsibilities

• Define the team's technical vision and architectural direction.
• Own the Booking and Search domain and improve usability and performance for both customers and internal users.
• Work hands-on with the team on backlog items and complex technical challenges.
• Review designs and facilitate important technical decisions.
• Guide the maintenance and improvement of critical external applications and supporting tools, including updates pushed by our software vendor.
• Improve monitoring and alerting to enable fast response, and find structural fixes or mitigations.
• Work towards decoupling our systems from external applications by implementing an anti-corruption layer and creating a stable domain that shields our internal systems.
• Collaborate with business users, other engineering teams and software vendors on changes, issues and dependencies.
• Translate product needs into practical technical solutions and help break down complex work.
• Improve engineering quality through code reviews, documentation, pairing and knowledge sharing.
• Mentor engineers and help them grow their technical skills and ownership.
• Communicate technical risks, trade-offs and dependencies clearly.

Skills

C#

.NET

System design

Architecture thinking

English communication

Mentoring

Ownership mindset

Tools

Azure

Kubernetes

CI/CD

Job description

At Sunweb Group, we're building and evolving the core systems behind millions of holidays each year. As a Senior Software Engineer in Team Capri, you'll own our Booking and Search domain, which is at the heart of how customers find and book their holidays. You contribute directly to how our platform is designed, scaled and improved.

You'll work in a small, autonomous Agile team of four (two developers and two application engineers), where ownership, pragmatism and quality go hand in hand. This role goes beyond coding. You influence architecture, improve engineering practices and help the department grow.

Location: Rotterdam Sunweb Group office (Hybrid)

Start date: December 2026

Availability: Fulltime

What you’ll do

• Help define the team's technical vision and architectural direction.
• Own the Booking and Search domain and improve usability and performance for both customers and internal users.
• Work hands-on with the team on backlog items and complex technical challenges.
• Review designs and facilitate important technical decisions.
• Guide the maintenance and improvement of critical external applications and supporting tools, including updates pushed by our software vendor.
• Improve monitoring and alerting to enable fast response, and find structural fixes or mitigations.
• Work towards decoupling our systems from external applications by implementing an anti-corruption layer and creating a stable domain that shields our internal systems.
• Collaborate with business users, other engineering teams and software vendors on changes, issues and dependencies.
• Translate product needs into practical technical solutions and help break down complex work.
• Improve engineering quality through code reviews, documentation, pairing and knowledge sharing.
• Mentor engineers and help them grow their technical skills and ownership.
• Communicate technical risks, trade-offs and dependencies clearly.

Our tech stack

C#, .NET, Azure, SQL, React, GitHub, GitHub Copilot, Visual Studio / VS Code

We actively leverage AI-powered tools such as GitHub Copilot to improve productivity and code quality.

What you bring

• 5+ years of experience with C# and .NET
• Experience building cloud-native applications on Azure
• Strong knowledge of SQL and data modelling
• Solid understanding of system design and clean architecture
• Experience with CI/CD, automated testing and DevOps practices
• Experience with legacy systems and modernisation
• Ability to balance speed and quality pragmatically
• Ownership mindset and drive to improve systems and processes
• Strong stakeholder communication skills in English (Dutch is a big plus)
• Experience mentoring others and shaping the technical vision and direction of a team
• Experience with Kubernetes 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

• You have real influence on architecture and technical decisions.
• You'll help move a legacy architecture to a modern, domain-based structure.
• Your work directly affects millions of customers searching for and booking their holidays.
• A pragmatic engineering culture focused on impact, feedback and growth.
• An international product with real scale and complexity.
• The opportunity to own and shape the technical direction and ways of working of the team.

Here’s what you can expect during our selection process:

• Initial conversation (via video) with our Talent Acquisition Specialist
• First interview (via video/ live) with the Team Lead and Head of Tech
• Second interview (via video/ live) with the Team Lead and a team member

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.

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