{"id":3283624,"url":"https://alion.io/job/openup-senior-net-full-stack-developer","title":"Senior .Net Full Stack Developer","company":{"id":456219,"name":"OpenUp","domain":"openup.com","url":"https://alion.io/company/openup-5","size_band":null,"is_staffing_agency":false,"employer_type":"direct","is_intermediary":false,"listed_via":null,"ats_vendor":"Greenhouse","truth_index":{"grade":"A","score":94,"open_postings":8,"ghost_share":0,"stale_share":0.25,"repost_share":0,"time_to_fill_p50_days":39,"computed_at":"2026-10-30T05:48:23Z"}},"role":"Backend","role_family":"Backend","seniority":"senior","employment_type":null,"work_mode":"remote","remote_scope":"stated_countries","remote_scope_basis":"board_field","remote_working_hours":null,"hiring_geo_confidence":"structured","locations":["Amsterdam, Netherlands"],"countries":["NL"],"hiring_countries":["NL"],"hiring_countries_total":1,"salary":null,"salary_estimate":{"min_usd":58000,"max_usd":99000,"period":"year","method":"role_seniority_country_cell","sample_n":73},"experience_years_min":5,"visa_sponsorship":false,"relocation_package":false,"has_equity":false,"technologies":[{"name":".NET","optional":false},{"name":"Angular","optional":false},{"name":"shadcn/ui","optional":false},{"name":"Tailwind CSS","optional":false},{"name":"Azure","optional":true},{"name":"C#","optional":true},{"name":"JavaScript","optional":true},{"name":"Radix UI","optional":true},{"name":"React.js","optional":true},{"name":"SQL","optional":true},{"name":"TypeScript","optional":true}],"status":"live","first_seen_at":"2026-10-26T13:17:10Z","employer_posted_date":"2026-10-26","last_verified_at":"2026-10-30T15:22:59Z","board_verified":true,"closed_at":null,"days_open":4,"trust":{"level":"ok","repost_count":null,"flags":[],"days_open":4},"description":"Who we are\nAt 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.\nOpenUp 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.\nAbout the role\nAs 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.\nOur tech stack: .NET 10, SQL Server, React, Azure\nAbout you\nOpenUp 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:\nYou are an experienced software developer with a strong track record in contributing to innovative projects.\nYou have a bachelor's degree in computer science or a similar education.\nYou have 5+ years experience working with backend APIs on .Net \nYou have 2+ years experience working with React /Angular/Vue.\nYou have experience with devops.\nExperience with Tailwind/shadcn and Storybook is a plus.\nYou communicate well and enjoy mentoring more junior colleagues.\nYou like to come up with creative yet pragmatic solutions to complex problems.\nYou get positive energy from the dynamics of a scale-up environment.\nYou have knowledge of application design, architecture and common design patterns.\nYou have knowledge of unit/integration/E2E testing.\nWhat you can expect\nJoining 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: \n€1500 annual personal development budget\nClassPass: OpenUp contributes towards your classpass membership \nMonthly home internet/phone contribution (50EUR)\nDaily healthy and vegetarian lunch at our office.\nRegular office yoga, meditation classes or breathing exercises\nFlexible work model (hybrid and options for remote work).\nMonthly drinks and company wide summer fest and other fun activities.\n27.5 vacation days per year.\nFree and unlimited access for you and your family to all our products, including our psychologists.\nNext steps\nInspired to be part of OpenUp? We’d love to hear your story. Apply via our website and we’ll get in touch soon.\nIf you have questions, please visit our FAQ page or reach out directly.\nAt OpenUp, everyone is welcome to apply regardless of age, gender, background, nationality, or any other characteristic. What matters to us is high performance, a real drive to make an impact and the ambition to become the European market leader. If you're ready to OpenUp, join us!\nWe may use artificial intelligence (AI) tools to streamline parts of our recruitment process. These tools assist our recruitment team but do not replace human judgement. All hiring decisions are made by humans. 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