# Senior C# Developer at Yellowtail Conclusion

> Hybrid · Netherlands · Senior · Software engineering · open. Source: https://alderhq.app/jobs/recruitee%3Ayellowtail%3A2291295 (read 2026-11-08).

## Facts (observed)

- Company: [Yellowtail Conclusion](https://alderhq.app/companies/yellowtail-conclusion)
- Location text: Naarden, Noord-Holland, Nederland
- Where it can be done from (inferred): Hybrid · Netherlands (evidence: "Location: Naarden, Noord-Holland, Nederland")
- Posted: 2025-11-06 (367 days ago)
- First seen by alder: 2026-11-07 · last verified: 2026-11-08
- Reposted: 0 times · edited: 0 times
- Apply on the employer's site: https://yellowtail.recruitee.com/o/senior-c-developer
- Skills listed (inferred): Angular, C#/.NET, Azure, SQL

## Pay and sponsorship

- Posted pay: €41k–€64k per year (from the listing's pay field)
- Market band for similar posted roles (Netherlands, n 13): p25 €70k, median €77k, p75 €81k

## Description (the employer's text)

### Digital Resilience

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 Senior Developer. In this role, you are responsible for the technical realization of developing and maintaining our software, together with the team based in The Netherlands.

### Why is Senior C# Developer your next job?

As a Senior Developer, you are responsible for influencing, designing, and building roadmap items. You are hands-on in resolving technically complex issues for our customers, collaborating with our development team. You consistently consider the 'bigger picture' for both our customers and for KCD. There are ample opportunities within KCD to truly leverage your specific skills and qualities.

You can play a vital role in both modernizing the application and add new innovative functionality;

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.

### Requirements

### What we think is important

As a Senior Developer, you have numerous opportunities, freedom, and the ability to shape the future. We have confidence in your ability to do what is necessary. For that, you need to possess:

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

5+ years of professional development experience.

Strong experience with C# (.net framework and.net core)

Demonstrable knowledge and experience with data & software security;

Knowledge of C#, .NET full stack, entity framework, MS SQL Server and Azure;

Knowledge of API management;

AI adopter

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: .net MVC, jQuery, optionally Blazor or 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 .net core back end but have the opportunity to contribute across the stack if desired.

### What’s in it for you?

Salary between €3900 and €5300 gross per month;

€767,25 mobility budget per month (can be used for travel expenses or as additional salary);

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.

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Data: alder (https://alderhq.app). Cite https://alderhq.app/jobs/recruitee%3Ayellowtail%3A2291295 and the date you read it. Observed facts come from the employer's own listing; location reach, level, family and skills are inferences.