Freelance Backend Developers in .NET, Java, or Python

dept offers an internship for a Backend Developer in Amsterdam or Rotterdam. This position gives aspiring developers the chance to gain hands-on experience and learn from seasoned professionals. Role overview The internship centers on supporting backend development for active projects. Interns will join a team of experienced colleagues and take part in real-world software work. What you will do Assist in building and maintaining backend systems for ongoing projects Collaborate with a team of skilled professionals Share ideas and contribute code to development efforts

Join our innovative team at dev2 as a Senior Backend Developer specializing in AdTech. In this role, you will be responsible for designing and implementing robust backend systems that drive our advertising technology solutions. You will work closely with cross-functional teams to ensure seamless integration and performance of applications.

At Speakap, we are on a mission to revolutionize communication for frontline and deskless workers through our innovative mobile-first Employee Experience Platform. Our platform empowers over 600 clients and 400,000 users in diverse sectors such as retail, hospitality, and healthcare to stay connected, informed, and engaged directly from their smartphones, eliminating the need for traditional email and desktop communications.If you have a passion for crafting clean, scalable, and secure code and enjoy tackling challenges while bringing creative ideas to life, we invite you to join our dynamic team. Help us redefine the future of work and connectivity.What You Will DoYour main responsibility will be to develop and enhance our API, which serves as the backbone of our platform, facilitating communication between web frontends, mobile applications, and third-party services.Collaborate with cross-functional teams to implement new features and enhance existing ones.Ensure the security and performance of our services under all conditions.Engage in architectural discussions to influence technology choices and problem-solving strategies.What You’ll BringA Bachelor’s or Master’s degree along with over 5 years of experience in building scalable, high-performance, multi-tier software while adhering to SOLID principles and design patterns in an agile environment.A strong collaborative spirit, excellent problem-solving abilities, and a commitment to writing clean, maintainable code.Proficiency in PHP 8, ECMAScript 10+, TypeScript, modern frameworks (Symfony 6+ preferred), Docker, CI/CD, Git, and shell scripting.Experience with relational databases (MySQL, MariaDB), automated testing (PHPUnit, Behat), and performance monitoring with DataDog.Familiarity with AWS services (S3, SQS, Lambda, etc.), Linux environments, and network protocols; knowledge of Elasticsearch, Java (8/9), Redis, Lua, NGINX, or OAuth 2 is a plus.A passion for automation, ensuring thorough test coverage, and optimizing repetitive tasks for efficiency.What We OfferAt Speakap, we are more than just a workplace; we are a supportive team that values your growth, ideas, and well-being.

Join Our Team as a Backend Developer!At openclaims, we are pioneering the insurtech industry by providing a cutting-edge SaaS platform that streamlines car repair processes for insurers and fleets. As we expand our reach into various markets, we seek passionate individuals eager to enhance and scale our innovative product.Your Key Responsibilities:Own and optimize core backend functionalities of our platform.Collaborate with frontend developers to integrate user-facing elements.Act as a technical advisor during the development cycle, supporting various stakeholders.Design and implement workflow solutions and technical upgrades to our platform.Engage in our continuous improvement initiatives.About Your Team:Join a dynamic team of 6 developers committed to fast-paced collaboration and ownership of our projects.

DEPT® is a Growth Invention company that partners with well-known brands worldwide. The team includes more than 4,000 specialists delivering services in Brand & Media, Experience, Commerce, CRM, and Technology & Data. Clients include Google, Lufthansa, Meta, eBay, and OpenAI. Since 2021, DEPT® has held both B Corp and Climate Neutral certifications. This Frontend Developer Internship is part of the Experience & Engineering team based in Amsterdam or Rotterdam. The team blends technical expertise with design to create digital experiences for brands such as Gant, Inter Milan, bol.com, and Just Eat Takeaway. What you will do Take part in the DEPT® Campus talent program, where hands-on projects help build frontend development skills. Attend professional training sessions, masterclasses, and workshops that introduce the latest technologies. Receive guidance from a dedicated mentor who offers coaching and feedback tailored to your growth. Work alongside a group of over 40 developers, sharing knowledge and supporting each other's progress. Contribute to real development work from day one, no coffee runs or administrative chores. Requirements Currently living and studying in the Netherlands. This is a requirement for the internship.

airapps is seeking a Backend Engineer to join the team in Amsterdam. The focus of this role is on developing and maintaining software that powers scalable applications and high-performing systems. The backend work directly supports a seamless experience for users of airapps products. Role overview Build and maintain backend systems that enable airapps products to operate smoothly Contribute to the design and architecture of software solutions built for scale Work to enhance system performance and reliability Requirements Experience developing backend applications Interest in creating scalable and efficient systems Ability to design solutions that support a strong user experience This position is located in Amsterdam.

Join Databricks, a leader in data and AI, as a Backend Software Engineer. We are dedicated to empowering data teams to tackle the world’s most pressing challenges, from revolutionizing transportation to pioneering medical advancements. Our world-class data and AI infrastructure platform enables customers to leverage deep data insights for business enhancement. Founded by engineers with a customer-centric approach, we embrace every opportunity to address technical challenges, from crafting next-generation UI/UX for data interaction to scaling our services across millions of virtual machines. We are just getting started!As a Backend Software Engineer, you will collaborate with your team to develop infrastructure and products for the Databricks platform at scale.Your Impact:Our backend teams address various challenges across our vital service platforms. You may work on:Complex problems that bridge product and infrastructure, including distributed systems, large-scale service architecture, monitoring, workflow orchestration, and improving developer experience.Delivering reliable and high-performance services and client libraries for managing vast amounts of data on cloud storage solutions like AWS S3 and Azure Blob Store.Building dependable, scalable services using technologies such as Scala, Kubernetes, and data pipelines like Spark and Databricks, which power our pricing infrastructure handling millions of cluster hours daily, while developing features that empower customers to easily monitor and manage platform usage.

Join Protolabs and Be Yourself At Protolabs, we understand that women and people of color often hesitate to apply for positions unless they meet every requirement. As an equal opportunity employer, we are dedicated to fostering a diverse workplace where everyone feels valued. If you believe you might not meet every single qualification but are intrigued by this opportunity, we encourage you to apply. Your unique perspective could enhance our company!Why Choose Protolabs? As leaders in digital manufacturing, we seek proactive doers, innovative makers, and creative thinkers who approach their work with an entrepreneurial mindset. Our culture revolves around impactful work that accelerates the development of innovative products. We take pride in our diverse team, characterized by intelligence, authenticity, humility, and passion. Our people fuel our creativity and make our workplace feel like home.Exciting Opportunity: Backend Software EngineerThis role is hybrid and we welcome applications from candidates residing in the Netherlands.You will be integral to the Manufacturing Partner Marketplace, the operational core of the Protolabs Network. This encompasses managing the entire order lifecycle—from matching orders with suitable manufacturing partners, overseeing production and quality control, to ensuring timely delivery. Your contributions are vital to maintaining operational efficiency and enhancing customer satisfaction.You will develop systems that empower the marketplace, including automated auctions, order allocation, supplier tooling, production workflows, global logistics, quality control, and internal operational tools.We seek a pragmatic problem solver who thrives in a dynamic environment and takes ownership of business challenges, not just technical solutions.Our Technology Stack: Backend: Python 3.11 with FastAPI, Flask, and SQLAlchemy (including Celery with RabbitMQ for background tasks).

Join bunq and be part of the transformation in the banking sector! We are dedicated to simplifying banking experiences and redefining the essence of financial services. As a Backend Engineer, you will play a pivotal role in delivering an outstanding banking application by ensuring seamless, secure, and efficient functionality for our users. Leverage your coding expertise to enhance the Bank of the Free from behind the scenes.Embrace ResponsibilityAs a Backend Engineer at bunq, you will spearhead our backend development efforts, guaranteeing our employees and users benefit from unrivaled stability and performance.Developing user-facing features.Collaborating with product teams to propose and design backend structures for new features, while supporting other departments through process development and maintenance.Utilizing technologies such as MySQL, Redis, Elasticsearch, and PHP to enhance the Bank of the Free.

Are you ready to transform the banking experience? At bunq, we strive to simplify lives and redefine banking for everyone. This is your opportunity to contribute to the future of digital banking, creating the ultimate app experience. Leverage your coding skills to develop and enhance the Bank of The Free, ensuring seamless, secure, and flawless functionality for our users.Take OwnershipAs a Senior Backend Engineer at bunq, you will lead our backend development, providing users and employees with unmatched stability and performance.Collaborate with our product team to design and implement robust backend structures for innovative user-facing features, utilizing technologies such as MySQL, Redis, Elasticsearch, and PHP.Support the growth of our backend team by mentoring junior developers and helping them reach their full potential.Oversee high-availability production systems and assist other departments by developing and maintaining efficient, scalable processes.

Since its inception in 2018, Bitvavo has pioneered the digital assets trading landscape, creating a seamless bridge between traditional currencies and digital assets. Our platform is designed with transparency in mind, featuring competitive fees and an extensive range of assets, ensuring that the currency of the future is accessible to everyone.Within just two years, we have cemented our status as the leading digital asset exchange in the Netherlands and one of the largest in Europe, boasting over one million users and facilitating the exchange of tens of billions in digital assets annually.Based in Amsterdam, we are on the lookout for innovative and motivated individuals who are eager to contribute to our mission of making digital assets universally accessible.About the OpportunityWe are a dynamic and rapidly expanding engineering organization dedicated to enhancing customer access to digital assets. In response to our expanding user base and the increasing diversity of assets we offer, we're looking to grow our teams to foster innovation focused on creating and implementing advanced services within the crypto market.As we continue to evolve, we welcome experienced engineers who are passionate about making a difference. This position is continually open, and we review applications on a rolling basis. While response times may vary based on our hiring needs, we encourage you to reach out if this role aligns with your expertise. We look forward to connecting with you when a suitable opportunity arises.Your ResponsibilitiesWork collaboratively with your Engineering Manager, Staff Engineer, and fellow team members to develop high-quality software for our clients.Tackle technical challenges head-on, crafting solutions to ensure optimal performance across our systems.Engage actively in critical decisions related to technology stacks and architectural frameworks.Participate in operational rotations to address incidents within our production environment.Qualifications We SeekA minimum of 8 years of experience in software development.Deep understanding and expertise in event-driven microservices architecture, particularly with Kafka.Strong proficiency in JVM languages, especially Kotlin.Familiarity with Kubernetes and a solid grasp of design patterns and programming principles.

Are you ready to embark on a journey where your work directly influences the housing market across the Netherlands? Join Funda as a Junior Backend .NET Engineer and contribute to a platform that helps millions of individuals find their next home. You'll gain invaluable experience from seasoned colleagues, develop real features, and witness the immediate impact of your contributions. Rather than joining just another tech firm, you'll play a vital role in enhancing the country's premier housing platform.Your Role at a GlanceImmerse yourself in the dynamic field of backend development, encompassing tasks from creating microservices to optimizing existing systems. You'll be guided by expert engineers who will challenge you to assume greater responsibilities—from your first pull request to deploying your very own features in a live environment.You will work with cutting-edge technologies such as .NET 8, Azure, and Kubernetes, learning to craft code that is not only functional but also scalable, secure, and straightforward to maintain.Your ResponsibilitiesCollaborate with your team to develop backend features for the Funda platform, which may include an API for property data retrieval or integration with mortgage information.Implement small enhancements to existing services and understand how our microservices interconnect.Create unit tests and refine your code based on peer feedback.Assess feature performance and devise strategies to enhance speed and stability.Engage in discussions regarding technical design decisions and learn how to build scalable systems.Become proficient with modern tools such as Azure DevOps, Docker, and Kubernetes.Explore Our Engineering Blog: Tom's career shift from musician to engineer at FundaYour TeamAt Funda, diverse scrum teams are dedicated to enhancing various segments of our platform—from refining the search experience to updating the systems used by real estate agents to manage their listings.We are actively seeking talent for multiple teams. Throughout the recruitment process, we will collaborate with you to identify where your skills, interests, and aspirations align best.

Tebi builds a unified restaurant management system that connects sales, reservations, kitchen prep, payments, and analytics on one platform. The company’s technology supports hospitality teams as they streamline operations and improve service quality. Founded by Arnout Schuijff, co-founder of Adyen, and backed by €50 million from Index Ventures and CapitalG, Tebi already serves thousands of restaurants, cafés, bars, and coffee shops in the Netherlands, the UK, and beyond. Role overview This is a full-time position for recent or soon-to-graduate engineers interested in backend or mobile development. As one of Tebi’s first Graduate Software Engineers, you will join a team where learning and growth are central. The role offers hands-on experience with backend systems that handle financial transactions and real-time data, and the chance to help shape features that support restaurant teams daily. You will work closely with experienced engineers, starting with clear, manageable tasks. Guidance is provided through code reviews and regular feedback. Over time, responsibilities expand as your skills develop. The stack includes Kotlin (for backend and mobile), Google Cloud Platform, and PostgreSQL. What you will do Contribute to the codebase, focusing on backend features with support from senior engineers. Work on well-defined tasks such as fixing bugs, creating small endpoints, and improving services, with opportunities to take on larger projects as you grow. Participate in code reviews and learn Tebi’s coding standards and practices from experienced teammates. Write clean, maintainable code while building skills in testing, version control, and deployment. Join merchant visits to see how Tebi’s platform is used in real restaurant settings. Adopt a learning mindset: ask questions, experiment safely, and develop into a confident backend engineer with support from the team. Requirements Recent or soon-to-be-completed degree in Computer Science, Software Engineering, or a related field. Interest in software development and motivation to build technical skills. Some familiarity with Kotlin or another programming language, along with a basic understanding of backend development concepts. This position is based in Amsterdam.

Are you passionate about crafting intelligent and scalable solutions? Do you thrive in tackling complex systems alongside enthusiastic colleagues? As a Medior Backend .NET Engineer at Funda, you will develop software that empowers millions to navigate the housing market daily. From rapid search results to sophisticated data integration, your contributions will significantly enhance how the Netherlands discovers homes.Your Role at a GlanceIn this position, you will produce high-quality code for a platform that attracts tens of millions of visitors each month. You will utilize cutting-edge technologies such as .NET 8, Kubernetes, Azure, and event-driven architecture, deploying your code to production daily via Azure DevOps.Your responsibilities include full ownership of the services and features you develop, collaborating closely with colleagues to drive continuous improvements. This unique role offers the scale of Funda, the excellence of our codebase, and the autonomy to make a tangible impact.Key ResponsibilitiesEnhance and develop features that directly improve user experiences, such as accelerating search results or optimizing data streams for our calculation tools.Contribute to the evolution of our microservices architecture, ensuring systems remain stable, scalable, and easy to maintain.Diagnose and resolve issues, from identifying performance bottlenecks to implementing intelligent caching strategies.Collaborate with Funda's engineers, product designers, and product managers to transform innovative ideas into robust solutions.Conduct code reviews, share insights with team members, and learn from seasoned engineers.Take ownership of your code and ensure its quality even post-release.For additional insights, check out our Engineering blog: The benefits of having a lighthouse architectureYour TeamAt Funda, multiple scrum teams focus on various aspects of our platform, ranging from enhancing the search experience to revamping the system used by real estate agents for property management.

Join our innovative team at Databricks as a Senior Backend Software Engineer, where you'll contribute to cutting-edge data solutions and scalable systems. Collaborate with a talented team to design and implement robust backend services that power our platform, enabling businesses to unlock the full potential of their data.

Role overview Creative Fabrica is looking for a Senior Backend Engineer with strong Go experience to help shape the foundation of its digital platform. The focus is on building and refining scalable backend services that power a growing creative marketplace. What you will do Collaborate with a talented team to design, develop, and maintain backend systems using Go Support the reliability and efficiency of backend services as the platform expands Share ideas and technical solutions to enhance user experience and add new platform features Address challenging technical problems in backend development Location This role is based in Amsterdam, North Holland, Netherlands.

Join Studytube as a Backend Engineer in Amsterdam and play a pivotal role in empowering individuals to shape their futures! We are in search of a talented backend engineer to develop and enhance integrations for our clients, working collaboratively with the Integrations team based in Amsterdam.Key ResponsibilitiesAs a Backend Engineer, you will serve as a vital link between Studytube and our clients, facilitating integrations between our platform and their HR systems. A recent challenge involved creating a new password flow for clients without email access, such as blue-collar workers, showcasing the innovative solutions you'll bring to the table. Your creativity is encouraged as you tackle unique integration challenges based on each client's requirements.In this role, your primary responsibilities will include:Developing integrations with external systems.Managing large volumes of historical data to onboard clients effectively.Designing, developing, and maintaining integrations focused on identity management.Continuously enhancing the existing platform with a focus on quality and efficiency.Collaborating closely with fellow engineers, product teams, and customer-facing staff.

Seeking a new adventure? You’ve found the perfect opportunity.Join our dynamic Amsterdam-based team, comprised of over 90 talented individuals from more than 25 nationalities! We are a diverse group of "Citizens of The World" who share a passion for travel and possess a wealth of skills. Our common goal? To revolutionize the way people explore the globe.We are achieving this with our innovative travel app designed to plan, track, and relive journeys in an intuitive and beautiful manner.With over 19 million users already on board, we believe this is just the beginning. Our ambitious plans for the future call for more talented and enthusiastic individuals to join us on this exciting journey.Curious to learn more about us? Discover more here.Your mission: Lead Backend Engineer at PolarstepsIf you haven't yet explored our app, take a moment to do so; you'll quickly realize how much we prioritize a seamless, high-quality user experience for every traveler. Our app has received impressive ratings of 4.8 and 4.7 on app stores and has been featured multiple times. Moreover, Google has created this fantastic video about us, and we've been mentioned in two of Apple’s WWDC keynote addresses!While we take pride in our remarkable past, we are even more excited about the future. The impact you can make from your very first day is significant, with every contribution affecting over 19 million users. We truly believe in providing our team members with the autonomy needed to perfect their craft while fostering a practical mindset to prevent over- or under-engineering.The travel industry is experiencing enthusiastic and accelerated growth, bringing both opportunities and challenges, particularly within the intricate, multi-layered travel domain. If you thrive on considering user experience, performance, and scalability, along with the inherent challenges of feature development, you’re in for an exhilarating experience with us.Your daily adventuresHere’s what your day-to-day will look like at Polarsteps.You will:Lead the platform team of Senior Backend and DevOps Engineers, establishing clear technical direction and expectations while maintaining close engagement with the code to identify potential issues.

airapps is looking for a Backend DevOps Engineer based in Amsterdam. This position centers on optimizing backend systems and supporting the integration of development and operations workflows. Role overview As a Backend DevOps Engineer, the main focus is on maintaining and improving infrastructure. The work involves close collaboration with cross-functional teams to streamline deployment processes and help ensure reliable product performance. What you will do Optimize backend systems for stability and efficiency Work with development and operations teams to improve integration Enhance infrastructure and support deployment improvements Contribute to the ongoing success of airapps products