Senior Software Engineer I

SeniorSoftware Engineer–.NET/AzureTaxPlatform

Amsterdam | Hybrid Work Model | Full-Time Build software professionals trust when accuracy matters most. Nextensdevelops the leading tax and compliance platform for professionals in the Netherlands. Trusted by thousands of experts, our softwaresupports more than 1 million filings each year andhelps organizationsnavigateevolving tax rules,high-volume data, and complexworkflows with precision and reliability. Built on deep domainexpertiseand a commitment to continuous innovation,Nextensnot only ensures compliance,weset the standard for how taxprofessionalswork. Your Role

As aSeniorSoftware Engineer atNextens, youown meaningfulparts ofa business-critical platform used daily by thousands of professionals.You designanddeliver robust software,make soundtechnical choices, and helpraise the quality of aplatformwhere accuracy, reliability, andmaintainability truly matter. You enjoycomplex engineeringchallenges andbring the judgement to balancequality, delivery,andlong-term maintainability.Together with domain experts, fellow engineers, and product owners, youtranslate changing fiscal requirements intosoftwareour customers can trust completely. You will join Team Fiscal, a product engineering team responsible for key parts of our Dutch tax filing platform. Together with fiscal experts and product colleagues, the team translates changing legislation into reliable software for tax professionals across the Netherlands. Key responsibilities include

Design, build,andevolvecore modules for tax filing and compliance,taking ownership from solution design through long-term maintainability. Use modern engineering practices, including AI-assisted development tools whereappropriate, to improve productivity, quality, and maintainability. Developand improveback-end and front-end components,APIs, interfaces,andintegrationsfora scalable,stable platformwith large data volumes and complex tax logic. Contribute to new features and innovations, such as integrations with external systems and tools for tax advisory workflows. Work closely with domain experts and product owners to translate regulations and customer needs into reliable software solutions. Improve engineeringqualitythrough testing, refactoring,code reviews,andmentoring other engineers. What You Bring

Abachelor’s degree in Computer Science, Software Engineering, or equivalent experience. 4+ years of hands-on software development experience, with evidence of increasing technical ownership, preferably with C#, .NET, Azure, and modern web technologies. A strong quality mindset, including testing, refactoring, code reviews,clean architecture principles, and coaching others to raise engineering standards. Interest in using AI-assisted development tools responsibly as part of everyday engineering work. Strong analytical and problem-solving skills, especially when working with complex logic or data. A collaborative mindset — you enjoy working closely withengineers and domain expertstocreatepractical,high-qualitysolutions. A focus on clean, maintainable code and a habit of writing tests to ensure quality. Fluency in English isrequired. You can read and understand Dutchrequirementstexts; spoken Dutch is helpful but not essential. Why Join Us

AtNextens, your work powers the backbone ofprofessionalDutch tax processing and helps thousands of professionals work smarter, faster, and more confidently. Our customers trust us not only for accuracy and compliance, but also because we innovate and improve how they work. What makes this role unique

Technical challenges → scalable systems, evolving regulations, and high-volume data processing. Real impact → your solutions directly support over 1 million filings every year. Ownership →takeresponsibility forimportantplatformareasandhelp guidetechnical choices. Technical leadership → mentor colleagues and help raise engineering quality across the team. What we offer you

Hybrid flexibility

→ combine working from home with collaboration at our modern Amsterdam office. Work-life balance

→ flexible hours, generous vacation days, and up to

20 daysof remote work abroad

per year. Competitive package

→ a strong salary, attractive benefits, and professional development opportunities. Great environment

→ a collaborative workplace, fully equipped in-house gym, and regular team-building activities. SeniorSoftware Engineer–.NET/AzureTaxPlatform

Amsterdam | Hybride werkmodel | Fulltime Bouw software waar correctheid geen bijzaak is. Nextens ontwikkelt het toonaangevende platform voor fiscale software en compliance in Nederland. Duizenden belastingadviseurs en financiële professionals vertrouwen dagelijks op onze oplossingen om te voldoen aan wet- en regelgeving, efficiënter te werken en zorgeloos aangifte te doen. Onze softwareondersteuntjaarlijksmeer dan1miljoen aangiftes enhelptorganisatiesom