Senior .NET Full Stack Developer

Who we are

At OpenUp, our mission is to make mental well-being accessible to everyone. Following a ‘high tech & high touch’ approach, we support companies, their employees, and their families with proactive and practical mental health services. Through our digital platform, clients can access 1:1 check-ins, online courses, articles, videos, group sessions, mindfulness practices, and a team of committed mental well-being experts. As we believe that mental and physical well-being are deeply connected, we have also added Lifestyle Experts to our offering, focusing on nutrition, exercise, and sleep. We offer a truly holistic approach that helps people take ownership of their health. We’re proud to work with forward-thinking organizations and are committed to raising the bar on accessible care.

OpenUp was ranked in the Top 3 on LinkedIn’s Top Startups list for 2023, 2024 & 2025 and is continuously growing. We are expanding our international teams and we are searching for like-minded talent. We are already serving 2000+ companies (e.g. Rituals, Deloitte, Decathlon, KPMG, and McDonalds), through which 600K+ employees have access to our product.

About the role

As a full stack software developer at OpenUp you will be a key member of our tech and product team. Besides writing clean and practical code you will also mentor other team members, make key architectural decisions, assist our tech lead with hiring, collaborate with 3rd parties and most importantly work together with the team to develop our mental health platform.

Our tech stack: .NET 10, SQL Server, React, Azure

About you

OpenUp loves people. We hope you do too. You enjoy working with people and you like to work in a team. You are enthusiastic about mental health, which is a topic as normal as going to the gym. Your motto is: you can learn from setbacks and you should celebrate success! Next to that:

• You are an experienced software developer with a strong track record in contributing to innovative projects.
• You have a bachelor's degree in computer science or a similar education.
• You have 5+ years experience working with backend APIs on .Net 
• You have 2+ years experience working with React /Angular/Vue.
• You have experience with devops.
• Experience with Tailwind/shadcn and Storybook is a plus.
• You communicate well and enjoy mentoring more junior colleagues.
• You like to come up with creative yet pragmatic solutions to complex problems.
• You get positive energy from the dynamics of a scale-up environment.
• You have knowledge of application design, architecture and common design patterns.
• You have knowledge of unit/integration/E2E testing.

What you can expect

Joining OpenUp means being part of a fast-growing company that's doing something meaningful. You'll work with a diverse and international team. We like to have fun together with a lot of team building activities like our weekly ‘borrels’ and after work sport classes, the yearly ski-trip and our Padel tournament. Which makes our work fun, challenging and dynamic. Apart from this, we offer: 

• €1500 annual personal development budget
• ClassPass: OpenUp contributes towards your classpass membership 
• Monthly home internet/phone contribution (50EUR)
• Daily healthy and vegetarian lunch at our office.
• Regular office yoga, meditation classes or breathing exercises
• Flexible work model (hybrid and options for remote work).
• Monthly drinks and company wide summer fest and other fun activities.
• 27.5 vacation days per year.
• Free and unlimited access for you and your family to all our products, including our psychologists.

Next steps

Inspired to be part of OpenUp? We’d love to hear your story. Apply via our website and we’ll get in touch soon.

If you have questions, please visit our FAQ page or reach out directly.