Senior Fullstack developer

About the role:

We are looking for an experienced Fullstack Developer to strengthen one of our core product teams in Belgium. The team builds and maintains three business‑critical applications widely used across the Belgian accountancy and payroll landscape. This role goes far beyond implementing features. You will be entrusted with end‑to‑end responsibility for the reliability, maintainability, and functional correctness of software used daily by thousands of accountants and organizations. 

Which tasks can you expect?

• Develop a deep functional understanding of our domain, with a strong focus on Belgian wage and tax regulations
• Take ownership of complete features: from functional analysis and technical design to implementation, testing, monitoring, and maintenance
• Monitor and safeguard production systems, ensuring daily processes run smoothly and addressing incidents with priority and precision
• Investigate and track down complex issues in existing code, balancing pragmatism with long‑term maintainability
• Think critically and contribute functional and architectural ideas that simplify workflows and improve product quality
• Participate actively in all stages of the product lifecycle: ideation, development, production, and continuous improvement
• Collaborate with infrastructure, support, and operational teams to ensure robust, performant deployments
• Perform code reviews and champion best practices in clean code, maintainability, testability, and security
• Share knowledge and help cultivate a high‑standard engineering culture within the team

What do you have to offer?

• 5+ years of experience in .NET development in complex software environments
• Experience with Angular
• ORM knowledge: NHibernate or Entity Framework
• Experience with NServiceBus
• Familiar with Git, Azure DevOps, CI/CD pipelines
• Strong background in test automation
• Strong SQL knowledge
• Experience building and consuming Web APIs
• Understanding of web security principles
• Fluency in English (spoken and written)

What do we have to offer?

• Stable employment conditions: permanent employment contract (after a 3-month probation period)
• Flexible working hours and remote work opportunities
• Private medical care (LuxMed)
• Cafeteria system / Sports card
• Lunch card (Edenred)
• Financial allowance for remote work
• Loans for employees
• Workation: possibility to work from any SD Worx location (4 weeks per year, EU only)
• Life insurance
• Holiday allowance
• Free language courses (during your working hours)
• Annual bonus
• Integration events
• Free parking spaces for employees
• Referral program
• PPK (Employee Capital Plans): 3.5% employer contribution
• Learning opportunities: through an individual development plan and professional training
• Career growth: whether you want to become more of an expert in your field or expand your knowledge horizontally, there’s always room to grow within SD Worx!

In today’s new world of fluid work, people want to be inspired by what they do and have the freedom to focus on what matters. Organisations need a dynamic, motivated workforce empowered by smart technology. As a leading European provider of integrated HR solutions, SD Worx turns HR into a source of value for their customers’ business and the people that work for them. SD Worx delivers HR solutions across the entire employee lifecycle, from paying employees to attracting, employing, rewarding and developing the talent who make businesses succeed. SD Worx powers performance through four core capabilities: software, outsourcing, consultancy and data-driven insights. 

SD Worx is the trusted leading European provider of end-to-end HR solutions for all organisations and workers. About 90,000 small and large organisations across Europe place their trust in the company and its +75 years' worth of experience. SD Worx calculates the salaries of approximately 5.7 million employees and ranks among the top five worldwide. The more than 7,500 employees operate in Belgium (HQ), Austria, Bulgaria, Croatia, Czech Republic, Denmark, Estonia, Finland, France, Germany, Hungary, Ireland, Italy, Luxembourg, Mauritius, Netherlands, Norway, Poland, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland and the UK. SD Worx achieved a consolidated revenue of EUR 1.058 billion in 2023.