backend developer

Firely

<div><h4 class="jobSectionHeader">Position details</h4><div>
Amsterdam | Hybrid | 32&ndash;40 hours | No Visa Sponsorships!
About the role
At Firely, we build enterprise-grade software that makes health data more accessible and more useful. Our FHIR server is at the heart of that work, helping healthcare organizations around the world exchange data more reliably and efficiently.
Yes, it&rsquo;s technical. But it&rsquo;s also meaningful. Better health data exchange means better informed care.
To help us push that further, we&rsquo;re looking for a talented and curious Backend Developer (.NET) to join our development team. This role is for someone who enjoys owning their work, diving into hard problems, and contributing to a standard that&rsquo;s shaping the future of healthcare.
You&rsquo;ll work in a small, collaborative team alongside a product owner, lead developer/architect, and fellow engineers. You&rsquo;ll have real autonomy over your technical scope and senior colleagues to think alongside when the problems get complex.
What you&rsquo;ll be doing
You&rsquo;ll contribute to the development and improvement of Firely Server, our flagship FHIR server product. That means building new features, improving performance, and helping shape the technical direction of what we ship.
In this role, you will:<ul><li>
Design and implement backend features in .NET / C#</li><li>
Work with REST APIs to enable reliable health data exchange</li><li>
Write and optimize queries across MS SQL Server and/or MongoDB; including indexing strategies and schema design for healthcare data</li><li>
Handle and validate JSON/XML payloads in line with FHIR specifications</li><li>
Contribute to code reviews, technical discussions, and architectural decisions</li><li>
Use AI tools to support development, planning, and quality assurance</li><li>
Collaborate with colleagues and, where relevant, engage with the wider FHIR community</li></ul>
Who we think will thrive here
You&rsquo;re someone who takes ownership, asks good questions, and cares about the quality of what you ship. You&rsquo;re energized by technically challenging work, comfortable with ambiguity, and not put off by a spirited debate in the FHIR community.
Required</div><div><ul><li>
Proficiency in .NET / C# backend development</li><li>
Solid understanding of REST APIs and how to work with them effectively</li><li>
Database experience with MS SQL Server and/or MongoDB</li><li>
Experience with AWSor Azure</li><li>
Experience handling JSON/XML payloads, including validation and storage</li><li>
Experience using AI tools to support development, planning, and quality assurance</li><li>
Familiarity with Git and tools like Jira, GitHub Projects</li><li>
Already authorized to work in the Netherlands</li><li>
Fluent English (written and spoken)</li></ul>
Nice to have<ul><li>
A bachelor&rsquo;s degree in computer science or equivalent working level</li><li>
At least 2 years of .NET / C# backend development experience</li><li>
Knowledge of HL7 and/or FHIR</li><li>
Familiarity with additional data stores such as PostgreSQL or cloud-native databases (e.g.Azure Cosmos DB, AWS RDS)</li><li>
A background in or curiosity about the healthcare sector</li></ul>
What you&rsquo;ll get from us
We want this to be a place where you can do great work, keep growing, and feel genuinely trusted with things that matter. You can expect:<ul><li>
Real ownership of your work, with support from experienced colleagues</li><li>
Plenty of room to develop your skills across a technically rich stack</li><li>
Active involvement in hackathons and international FHIR working group meetings</li><li>
A salary between &euro;5,000 and &euro;6,000 gross per month based on a 40-hour workweek</li><li>
27 holidays based on a 40-hour work week</li><li>
A hybrid role (with 2 days in the office), full-time or 4 days &mdash; you choose</li><li>
NS Business Card to travel 1st class to work</li><li>
Bring your own device or budget to purchase a new one</li><li>
Budget to set-up your home office</li><li>
Annual budget to support your growth and development</li><li>
A cozy office in the heart of Amsterdam with a canal view 
 
Questions about this role? Reach out to our HR &amp; Recruitment team at recruitment@fire.ly</li></ul></div><h4 class="jobSectionHeader">
About us</h4><div>
Be part of the revolution in Health Informatics! 
 
Firely is a digital healthcare scale-up. We specialize in software and services in healthcare and research. The company is one of the initiators of HL7 FHIR (pronounced &ldquo;fire&rdquo;), a new international standard for information exchange in healthcare. By making health data more accessible, Firely helps developers worldwide build apps that ultimately benefit patients. Our customers are healthtech vendors, care providers, payers/insurance companies, governments, and health agencies in Europe and the US. 
 
Firely is a group of software engineers, support engineers, FHIR consultants, and a commercial team. Our head office is based in Amsterdam (the Netherlands), our international team works from Europe and the US. 
 
An important part of our activities is the involvement in the development of both the FHIR standard itself and FHIR tooling and open-source libraries. Besides that, we are the organizers of FHIR DevDays, and founding member of the FHIR Business Alliance (FHIRBall). We live and breathe FHIR, we talk FHIR to our computers, our colleagues, and even our friends which &hellip; frankly &hellip; drives them crazy! Working with Firely means working with FHIR, building software, and doing consultancy in an international team. It means FHIR DevDays. It means being part of the FHIR revolution. If you have the curiosity, passion, and collaborative spirit, work with us, and let's fire it up together! 
 
Apply by clicking on the 'apply for this position' button below. Please make sure you send us your CV and a motivation letter. 
 
Our Commitment to Equality 
 
Firely is proud to be an equal opportunity workplace. We are committed to equal employment opportunity regardless of race, color, ancestry, religion, sex, national origin, sexual orientation, age, citizenship, marital status, disability, gender identity, Veteran Status, or any other characteristic protected by law.</div></div>

FHIR Backend Developer | .NET

Client Server

<div>
 
 
 
 Full Stack Developer / Engineer (Kotlin AWS JavaScript) Amsterdam to &euro;85,000
 
 
 
 
 
 
 
 Are you a skilled Full Stack Developer looking for an opportunity to progress your career whilst working with a modern tech stack and continually improving your skills?
 
 
 
 
 
 You could be joining a scaling, global FinTech company, working on a successful product that helps global companies to achieve sustainability and NetZero targets via Blockchain technology solutions.
 
 
 
 
 
 As a Full Stack Developer you will work across the full technology stack with a focus on Kotlin backend systems but also with some front end (JavaScript, Angular / React) work. You'll quickly gain an understanding of the complete ecosystem of the modern, distributed application with a broad scope of work including AWS, mobile applications, trading and transfer functionality and integration of 3rd party platforms.
 
 
 
 
 
 This is an opportunity to work on worthwhile technology that is helping to increase decarbonisation whilst working on complex and interesting systems with continual learning opportunities.
 
 
 
 
 
 
 WFH Policy:
 
 
 
 You'll join colleagues in the Amsterdam office two days a week with flexibility to work from home the other three days.
 
 
 
 
 
 
 About you:
 
 
 <ul>
 <li>
 You have strong serverside Kotlin experience (Java background is good)
 </li>
 <li>
 You have experience with Spring Boot and microservices
 </li>
 <li>
 You have a thorough understanding of Computer Science fundamentals such as OOP, Design Patterns, Data Structures
 </li>
 <li>
 You have a good knowledge of AWS
 </li>
 <li>
 You have a good understanding of CI/CD, DevOps
 </li>
 <li>
 You also have some JavaScript, Angular, React front end skills
 </li>
 <li>
 You're collaborative, enjoy problem solving and continually learning
 </li>
 <li>
 You're keen to work in a start-up / scale-up environment with lots of ownership
 </li>
 </ul>
 
 
 
 
 
 What's in it for you:
 
 
 <ul>
 <li>
 Salary to &euro;85,000
 </li>
 <li>
 Flexible working in a relaxed technology focussed environment
 </li>
 <li>
 Continual learning and self-development opportunities
 
 
 </li>
 </ul>
 
 
 
 
 
 Apply now
 
 to find out more about this Full Stack Developer / Engineer (Kotlin AWS JavaScript) opportunity.
 
</div>

Full Stack Developer Kotlin AWS JavaScript - Start-up

TicketSwap

<div>
 
 At TicketSwap, we&rsquo;re on a mission to become the experience marketplace every fan loves. With over 19 million users across 42 countries, we&rsquo;re building a safe, fair, and easy way for fans to buy and sell tickets to live events around the world. Technology plays a central role in how we solve problems for fans. From scaling our platform and improving event creation to building safer ticketing flows, we&rsquo;re constantly working on products that make live experiences more accessible and trustworthy.
 
 
 
 
 We&rsquo;re built by fans, for fans. That means we care deeply about creating products that genuinely help people, and we believe the best ideas come from curious, collaborative teams who enjoy building together. Right now, we&rsquo;re looking for a Software Engineer Backend (PHP) to join our Engineering team in Amsterdam.
 
 
 
 
 Ready to help shape the future of live events? Keep reading 👇
 
 
 
 What You&rsquo;ll Do
 
 As a Backend Engineer at TicketSwap, you&rsquo;ll work on the systems that power millions of safe ticket transactions worldwide. You&rsquo;ll join a cross-functional product team alongside frontend, mobile, product, and design colleagues to build scalable features and improve the core marketplace experience. You&rsquo;ll have ownership, room to experiment, and the opportunity to see your work reach fans almost immediately.
 
 
 
 
 Your key responsibilities:
 
 <ul>
 <li>
 
 Build and improve backend services and APIs that power our platform
 
 </li>
 <li>
 
 Develop new product features used by millions of fans across web and mobile
 
 </li>
 <li>
 
 Help scale and maintain a reliable, secure, and high-performing marketplace
 
 </li>
 <li>
 
 Work with PHP, Symfony, MySQL, Redis, RabbitMQ, GraphQL, AWS, and Kubernetes
 
 </li>
 <li>
 
 Contribute to our event-driven architecture and asynchronous systems
 
 </li>
 <li>
 
 Collaborate closely with Product Managers, Designers, and Engineers across disciplines
 
 </li>
 <li>
 
 Write clean, maintainable, and well-tested code
 
 </li>
 <li>
 
 Participate in code reviews and contribute to improving engineering standards
 
 </li>
 <li>
 
 Help improve developer experience, tooling, and platform reliability
 
 </li>
 <li>
 
 Contribute ideas that simplify complex technical or product challenges
 
 </li>
 <li>
 
 Continuously learn, experiment, and share knowledge with the team
 
 </li>
 <li>
 
 Some of the projects we&rsquo;re currently working on:
 
 </li>
 <li>
 
 Expanding support for more ticket file types as the ticketing industry evolves
 
 </li>
 <li>
 
 Improving SecureSwap integrations to make events safer and easier to configure for partners
 
 </li>
 <li>
 
 Rebuilding and improving event creation flows across the platform
 
 </li>
 </ul>
 
 About You
 
 We know great engineers come from different backgrounds and experiences. If this role excites you, we&rsquo;d love to hear from you, even if you don&rsquo;t tick every box.
 
 
 What we&rsquo;re looking for:
 
 <ul>
 <li>
 
 3+ years of experience as a Software Engineer
 
 </li>
 <li>
 
 Strong experience with PHP and relational databases like MySQL
 
 </li>
 <li>
 
 Experience with frameworks like Symfony is a strong plus
 
 </li>
 <li>
 
 Comfortable working with Git and modern development workflows
 
 </li>
 <li>
 
 You care about code quality, testing, and maintainability
 
 </li>
 <li>
 
 You enjoy solving real user problems through technology
 
 </li>
 <li>
 
 You&rsquo;re curious, proactive, and open to learning new things
 
 </li>
 <li>
 
 You enjoy collaborating in cross-functional teams
 
 </li>
 <li>
 
 Experience with React, mobile development, AWS, Kubernetes, or DevOps tooling is a bonus
 
 </li>
 <li>
 
 You&rsquo;re based in the Netherlands, have an EU passport, or already hold a valid visa to work here
 
 </li>
 <li>
 
 Please note: we don&rsquo;t offer relocation support for this role.
 
 </li>
 </ul>
 
 
 Why You&rsquo;ll Love It Here
 <ul>
 <li>
 
 Work on products used by millions of fans around the world
 
 </li>
 <li>
 
 Join a high-talent, international team that values ownership and collaboration
 
 </li>
 <li>
 
 Ship meaningful work fast and see the impact directly
 
 </li>
 <li>
 
 Collaborate in an environment where ideas matter more than hierarchy
 
 </li>
 <li>
 
 Learn from experienced engineers who care deeply about quality and innovation
 
 </li>
 <li>
 
 Help shape the future of live events and ticketing
 
 </li>
 </ul>
 
 
 Practical Details
 <ul>
 <li>
 
 Full-time role
 
 </li>
 <li>
 
 Hybrid working setup
 
 </li>
 <li>
 
 Based in Amsterdam
 
 </li>
 <li>
 
 No relocation package provided
 
 </li>
 <li>
 
 This role sits within Function Group 6 or 7, depending on experience and seniority level. We&rsquo;re open to considering both mid-level and senior Backend Engineers
 
 </li>
 </ul>
 
 
 
 
 Excited to join us?
 
 
 
 Research shows that women and people from traditionally underrepresented groups often apply only when they meet every requirement. We&rsquo;d much rather hear from someone who&rsquo;s excited about the role and motivated to grow.
 
 
 At TicketSwap, we welcome people of all backgrounds, identities, and experiences. If this role feels like a good fit for you, we&rsquo;d love to hear from you 🚀
 
</div>

Software Engineer Backend

Frank Energie

<div>
 At Frank Energie we're looking for a Backend Software Engineer to join our team.
 
 
 
 About Frank Energie
 
 
 
 Frank Energie is a rapidly growing company located in the Amsterdam Zuidas district. We are revolutionizing the energy market, accelerating the energy transition, and making affordable sustainable energy accessible to everyone.
 
 
 We are young and ambitious, and we want to move fast. Working towards a greener world. We are already a major player in the Netherlands and are on the verge of conquering the rest of Europe. We expanded to Belgium, Spain and France. This year, we are heading to Denmark and Italy. Will you join us on this journey? Your job will be challenging, but for an ambitious person like you, definitely achievable. Your learning curve will be steep, and the growth opportunities are limitless. In addition to hard work, we also believe in relaxation and team-building activities &ndash; work hard, play hard.
 
 
 
 About The Job
 
 
 
 If you would like to develop backend features in a state-of-the-art infrastructure, have a self-starter attitude and tech-driven curiosity, know that a good opinion must be shared, and are willing to contribute together with a commited team, you can proceed with reading.
 
 
 We are looking for an experienced Software Engineer who will play a key role in building our high-performance, real-time power sourcing and optimization software. Our systems must efficiently process large volumes of data and energy market events, ensuring optimal energy sourcing &amp; optimization in a dynamic market.
 
 
 What you will be doing
 
 
 <ul>
 <li>
 Develop real-time power sourcing &amp; optimization software;
 </li>
 <li>
 Implement event-driven and non-blocking architectures to ensure rapid and scalable data processing;
 </li>
 <li>
 Work with Co/Goroutines to handle large-scale energy market data streams efficiently;
 </li>
 <li>
 Optimize system performance to manage fluctuating energy demand and supply conditions;
 </li>
 <li>
 Collaborate with data scientists, energy analysts, and backend engineers to improve forecasting and automation in power sourcing;
 </li>
 <li>
 Write clean, scalable, and well-tested code to support a reliable and adaptive energy sourcing platform;
 </li>
 <li>
 Have fun with your team!
 
 
 </li>
 </ul>
 
 What will help you succeed?
 
 
 
 
 Being An Expert In
 
 
 
 <ul>
 <li>
 You master at least Go or Kotlin and you are not afraid to start working with both of them;
 </li>
 <li>
 Data structures, algorithm design, problem-solving, complexity analysis, secure coding best practices and remediation;
 </li>
 <li>
 Designing, building and maintaining large-scale, high-performance, real-time systems and frameworks;
 </li>
 <li>
 Knowledge of databases (SQL/NoSQL) and message brokers like Kafka or RabbitMQ;
 </li>
 <li>
 Object-oriented concepts and systems design patterns;
 </li>
 <li>
 Analyzing and troubleshooting distributed systems;
 </li>
 <li>
 Tackling problems of load, scale, and optimizations of complex large-scale deployments;
 </li>
 <li>
 Modern server scaling technologies on Linux (e.g., async, non-blocking I/O, multithreading).
 
 
 </li>
 </ul>
 We offer
 
 
 <ul>
 <li>
 A challenging role in a fast growing company doing new things;
 </li>
 <li>
 An exciting adventure: Feels good to do something no one ever did before;
 </li>
 <li>
 Great colleagues: Young, international and dedicated team;
 </li>
 <li>
 Transparency. You don&rsquo;t execute the roadmap; you are part of it. No office politics here!
 </li>
 <li>
 Team building activities &ndash; &lsquo;work hard, play hard&rsquo;;
 </li>
 <li>
 Personal development focus and support;
 </li>
 <li>
 Entrepreneurship: Become a self-starter and take ownership;
 </li>
 <li>
 Momentum: We move at lightning speed.
 
 
 </li>
 </ul>
 Apply for the job
 
 
 Do you want to join our team as our new Backend Software Engineer? Then we'd love to hear about you!
</div>

Backend Software Engineer

Seenons bv

<div><h2 class="jobSectionHeader">Your launchpad to a career with impact</h2> 
Seenons is a tech company on a mission: a world without waste. As a certified B Corp, we&rsquo;re building the digital logistics infrastructure that enables organizations to separate, track, and route waste to its next best use, turning a fragmented, outdated system into one that&rsquo;s circular and future-proof. 
Our international platform brings together all players in the waste industry for circular waste management. We help large organizations reduce waste and save valuable resources from going to waste. We are currently active in four European countries and are planning to expand. As of now we are looking for a Software Engineer Intern (internally we use the title Product Engineer Intern) to join our Tech team.<h3 class="jobSectionHeader">
About the role</h3>
You'll join our engineering team of 8, working across our internal Cockpit and three customer-facing apps (Waste Saver, Data, Partner Portal). We work as one team, broken into smaller monthly projects - so you'll get to touch most of the platform during your time with us.
What you&rsquo;ll be doing:<ul><li>
Ship features end-to-end across the stack (frontend, backend, a bit of data, a bit of infra - whatever the problem needs)</li><li>
Use AI tooling (Claude, agents, and more) as a core part of how you build</li><li>
Talk to the people who'll use what you build, whether that's our internal business users or our customers out in the world</li><li>
Contribute to our internal libraries, patterns and the way we work</li></ul><h3 class="jobSectionHeader">
We&rsquo;d like to hear from you, if you</h3><ul><li>
Are AI-native: you've already built things with LLMs, you know what they're good at and (more importantly) what they're not, and you're allergic to &quot;but AI said so&quot; as a defense.</li><li>
Are eager to take ownership and have proved it with school projects, side projects, internships, or something you can show us.</li><li>
Have some experience with TypeScript, JavaScript or Python - ideally with a frontend framework (we use Vue), a backend one (we use NestJS), or both. Want to contribute full stack, even if you don't know all parts of it yet.</li><li>
Are pragmatic - you'd rather ship a useful 80% than polish a 100% that nobody asked for.</li><li>
You ask &quot;why are we doing this?&quot; and &quot;have we talked to a user?&quot; before reaching for the keyboard.</li><li>
Thrive in a dynamic environment where collaborating with a product manager, designer, engineers and end-users is part of the job.</li><li>
Study in the Netherlands and would like to work from the office at least three days a week.
</li></ul>Ah, one more thing...
If you&rsquo;re not entirely sure whether you meet all the requirements, but you&rsquo;re enthusiastic about us and the role, apply anyway! We want people who are also willing to take risks. Together we learn and grow.<h3 class="jobSectionHeader"> 
What you get with us</h3><ul><li>
Drive impact in the pursuit of a zero-waste future.</li><li>
Learn by doing alongside engineers who'll review your PRs properly.</li><li>
Join a supportive, collaborative team of 80+ international colleagues in a thriving scaleup.</li><li>
Work from our Amsterdam Houthavens office with a panorama harbor view, close to Amsterdam CS and Sloterdijk - with commuting costs reimbursed.</li><li>
Join fun events and office drinks to celebrate successes.</li></ul><h3 class="jobSectionHeader">
Done wasting?</h3>
Great, so are we. Tell us why this role excites you and how you&rsquo;d use your skills to help us grow. No long cover letter needed, just thoughtful input in our application form will do. Apply now, and let&rsquo;s build a waste-free future together.</div>

Internship: Software Engineer

Nebius

<div>
 
 
 About Nebius:
 
 
 
 
 
 
 Nebius is leading a new era in cloud infrastructure for the global AI economy. We are building a full-stack AI cloud platform that supports developers and enterprises from data and model training through to production deployment, without the cost and complexity of building large in-house AI/ML infrastructure.
 
 
 
 
 
 Built by engineers, for engineers. From large-scale GPU orchestration to inference optimization, we own the hard problems across compute, storage, networking and applied AI.
 
 
 
 
 
 Listed on Nasdaq (NBIS) and headquartered in Amsterdam, we have a global footprint with R&amp;D hubs across Europe, the UK, North America and Israel. Our team of 1,500+ includes hundreds of engineers with deep expertise across hardware, software and AI R&amp;D.
 
 
 
 
 
 
 The Role
 
 
 
 
 
 
 
 Your responsibilities will include:
 
 
 
 
 
 <ul>
 <li>
 Ensure fault-tolerance, scale, and uninterrupted operations for the service.
 </li>
 <li>
 Use cutting-edge cloud technology to solve a variety of infrastructure problems.
 </li>
 <li>
 Implement and improve CI/CD processes.
 </li>
 </ul>
 
 
 
 
 
 We expect you to have:
 
 
 
 
 
 <ul>
 <li>
 Solid experience with programming languages (like Go, Python, or C++);
 </li>
 <li>
 Solid understanding of classic algorithms and data structures;
 </li>
 <li>
 Commercial experience with and deep understanding of Unix systems and network technology;
 </li>
 <li>
 Experience with systems for containerization and configuration management (Ansible, Salt, Terraform, Docker, K8s, Helm).
 </li>
 </ul>
 
 
 
 
 
 It will be an added bonus if you have:
 
 
 
 
 
 <ul>
 <li>
 Desire to be involved in backend development;
 </li>
 <li>
 Experience designing, developing, and running high-load distributed systems;
 </li>
 <li>
 Commercial experience with a variety of cloud platforms.
 </li>
 </ul>
 
 
 
 
 
 We conduct coding interviews as part of the process.
 
 
 
 
 
 
 
 Benefits &amp; Perks:
 
 
 
 
 
 <ul>
 <li>
 Competitive compensation
 </li>
 <li>
 Career growth and learning opportunities
 </li>
 <li>
 Flexibility and ownership
 </li>
 <li>
 Collaborative and innovative culture
 </li>
 <li>
 Opportunity to work on impactful AI projects
 </li>
 <li>
 International environment and talented teams
 </li>
 </ul>
 
 
 
 
 
 What's it like to work at Nebius:
 
 
 
 
 
 
 Fast moving - Bold thinking - Constant growth - Meaningful impact - Trust and real ownership - Opportunity to shape the future of AI
 
 
 
 
 
 
 Equal Opportunity Statement:
 
 
 
 
 
 
 Nebius is an equal opportunity employer. We are committed to fostering an inclusive and diverse workplace and to providing equal employment opportunities in all aspects of employment. We do not discriminate on the basis of race, color, religion, sex (including pregnancy), national origin, ancestry, age, disability, genetic information, marital status, veteran status, sexual orientation, gender identity or expression, or any other characteristic protected by applicable law.
 
 
 
 
 
 Applicants must be authorized to work in the country in which they apply and will be required to provide proof of employment eligibility as a condition of hire.
 
 
 
 
 
 If you need accommodations during the application process, please let us know.
 
</div>

Senior Backend Engineer

Explore 31+ Backend developer in Amsterdam this July. Find roles across top companies and apply now to boost your career.