Introduction

At Yellowtail Conclusion, we develop software that strengthens digital security in one of the most digitized countries in the world: the Netherlands. One of our flagship products, Key Control Dashboard (KCD), enables organizations to manage risks effectively through smart, user-friendly technology.

To keep innovating, we’re looking for a Medior Front-End Developer that has some back-end experience who enjoys working with Blazor and modern front-end technologies. You’ll join a passionate, highly skilled development team based entirely in the Netherlands, contributing to a great platform.

Why This Is Your Next Job as a Medior Developer

Contribute to our UI transformation. We’re currently migrating our ASP.NET MVC application to a modern Blazor front end. As a medior developer, you’ll play an important role in this transition—building new components, refining user flows, and helping shape a clean, maintainable front-end architecture alongside our lead engineer.

Front-end focus, real impact. Your core responsibility will be developing and enhancing the new Blazor-based UI. You’ll work closely with backend developers, UX designers, and product owner to deliver a smooth and intuitive user experience.

Innovative environment. We encourage learning and experimentation. Have an idea to improve performance or user interaction? We want to hear it—and help you test it.

Growth and ownership. You’ll be trusted with real responsibility, contribute to technical decisions, and mentor junior developers as part of a collaborative team.

We truly value your talent and want to support your growth. At KCD, you will have ample learning opportunities and the freedom to discover your strengths.

What We Are Looking For

• A relevant bachelor’s or master’s degree in Computer Science, Software Engineering, or a related field;

• 3–5 years of professional development experience;

• Strong experience with C# and Blazor (Server or WebAssembly);

• A proactive mindset with strong communication skills in English (Dutch is an advantage);

• Team spirit: you enjoy collaboration, providing constructive feedback, and contributing to a dynamic team;

• Experience working within agile development teams and a solid track record of independently solving technical challenges.

Our Tech Stack

Front end: Blazor, jQuery (legacy), optionally Angular

Back end: C#, ASP.NET

Data & cloud: MS SQL Server, Azure

DevOps: CI/CD pipelines, code reviews, automated testing

You’ll primarily work on the Blazor front end but have the opportunity to contribute across the stack if desired.

What We Offer

• Competitive salary aligned with a medior role (details provided during an introductory conversation);

• A mobility allowance that you can use in an eco-friendly way (for example, opting for an electric lease car);

• All essential matters well-organized: a high-speed laptop, phone, excellent pension plan, travel allowance, and daily lunches;

• Flexible working: largely choose where and when you work. We believe in maintaining a healthy work-life balance and support you in setting up a comfortable home office or even working remotely from your favorite vacation spot;

• A friendly, informal culture: we frequently organize activities such as company trips, hackathons, sports events, and more. Every other year, there’s either a major company trip or a large-scale hackathon;

• Room for personal growth: you will receive mentoring and coaching from senior developers, enabling you to quickly learn and advance.