Freelance Backend Developers in .NET, Java, or Python

At Monks, we prioritize your safety. We will never ask for payment or banking information during the recruitment process. As we expand our teams, please be vigilant against fraudulent job postings or recruitment activities that misuse our name. Protect your personal information throughout the recruitment journey. While we may reach out to candidates via LinkedIn, all applications must be submitted through our official website (monks.com/careers).Monks is actively seeking exceptional Freelance Backend Developers to enhance our projects for Q3 & Q4! If you are proficient in .NET, Java, or Python, and possess practical experience with GCP and infrastructure, we would love to connect with you.Please note: Applicants must be Dutch nationals.Are you ready to engage in thrilling, diverse projects and leave your mark? Join us today—let's create something extraordinary together!About MonksMonks is the global, digital-first, data-driven operating brand under S4 Capital plc. With a legacy of innovation, we combine extensive global marketing and technology services to redefine brand interactions. Through our flagship AI ecosystem, Monks.Flow, we transform marketing into a growth engine, connecting brands to culture in real-time while delivering impactful creative solutions. We address critical business challenges, helping brands achieve sustained long-term success.Monks has been recognized as a Contender in The Forrester Wave™: Global Marketing Services, ranks among Cannes Lions' Top 10 Creative Companies (2022-25), and is featured annually in AdExchanger’s Programmatic Power Players list (2020-24). Additionally, we were honored as Adweek’s first AI Agency of the Year (2023) and received multiple awards for excellence in artificial intelligence.

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.

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.

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.

Are you a passionate engineer who enjoys both establishing frameworks and engaging directly in development? As a Senior Backend Engineer at Funda, you will design, build, and scale systems that assist millions of potential home buyers and real estate professionals daily. Your role bridges technology, architecture, and product development, allowing your voice to influence our direction.Your Role at a GlanceIn this position, you will be a key player in Funda’s backend domain. Your responsibilities include designing scalable systems, enhancing the technical foundations of our platform, and developing features that make a direct difference to millions of users.You will be part of a dedicated product team while collaborating across various teams: uniting people, ideas, and projects to advance our technical capabilities. Utilizing cutting-edge technologies such as .NET 8, Kubernetes, Azure, event-driven architecture, and Terraform, you will help keep our systems intelligent, scalable, and prepared for the future.This role uniquely combines deep technical expertise, ownership, and an influential voice in our development processes.Your Responsibilities IncludeGuide your team in alignment with our lighthouse architecture and contribute to its ongoing enhancement.Design and optimize critical systems demanding high performance and reliability.Tackle complex challenges related to scalability, data streams, and systems integration.Collaborate with product managers and designers to ensure technical choices align with the product vision.Mentor and share knowledge with mid and junior engineers, fostering Funda's culture of learning.Partner with other senior and staff engineers to evolve Funda’s technical strategy.Explore our Engineering Blog: Learn how we empower our development team with modular pipelines

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.

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

Are you passionate about tackling challenging technical projects across the Java spectrum? If so, Centric is the perfect fit for you. Our assignments are diverse: one day you might be developing an advanced web application for a booking website, and the next, you could be working on a portal for a health insurance provider. As a Full Stack Developer at Centric, you will have the opportunity to continuously enhance your skills and grow within your profession.Your ResponsibilitiesYou will immerse yourself in the world of Java, developing up-to-date applications using frameworks such as Spring, JPA, Hibernate, JavaEE, Angular, and React, along with build tools like Maven. Your effectiveness will be demonstrated by applying your knowledge and experience to satisfy client needs.Additional Duties Include:Setting up CI/CD environments using JenkinsImproving quality with tools such as SonarQube and version control using GitLabConducting tests with JUnit, Spring Test, or MockitoFacilitating data exchanges via gRPC, SOAP, and REST calls, and building solutions within a cloud-based microservice architecture.As a Full Stack Developer, you will be employed by Centric and deployed to one or more client sites, all within a maximum of one hour from your home. This variety will expose you to numerous organizations, assisting your continuous development in your field. You will collaborate with your Field Manager to create a personalized development plan outlining the courses, training, and assignments that align with your career aspirations. Finally, you will join our center of expertise, where knowledge sharing and peer coaching are paramount.What We OfferAt Centric, we provide a dynamic environment where you can leverage your skills on various challenging projects with exciting clients. You will have the opportunity to learn continuously and grow in a setting that is at the forefront of the latest developments. As a Full Stack Java Developer, you can expect:A gross salary of up to €5,600 per month, depending on your knowledge and experienceA profit-sharing scheme of up to 50% of the average gross monthly salaryA productivity bonusThe option to work from home and maintain a healthy work-life balance, as you can determine your weekly scheduleExtensive training and development opportunities26 vacation days, 8% vacation allowance (paid in May), and loyalty days: the longer you stay with us, the more free time you gainA contribution towards your pension and discounts on your collective health insuranceA company laptop and phoneA home office allowance of €15

Are you a passionate AI Developer with experience in .NET and Azure AI Foundry? Join our innovative team at Devoteam in Amsterdam, where we harness cutting-edge technology to drive business transformation. As an AI Developer, you will be responsible for designing and implementing AI solutions that meet our clients' needs. Your expertise will help us deliver outstanding results in a fast-paced environment.

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 JetBrains, a leader in developing tools that enhance the productivity and enjoyment of software development for programmers around the globe. We offer an impressive suite of .NET and game development tools, including ReSharper (a powerful extension for Microsoft Visual Studio and VS Code-like editors), Rider (a versatile cross-platform IDE for .NET and game development), and a variety of profiling and code coverage tools such as dotCover, dotMemory, dotTrace, and dotPeek. Marketing this diverse range of products entails collaborating with large enterprises and small game development studios alike, promoting established solutions alongside innovative newcomers, and fostering the integration of our IDEs into developers' daily routines while also driving awareness for specialized profiling tools. Our content team is dedicated to producing a wealth of marketing, educational, and promotional materials. We collaborate closely with developer advocates, technical writers, and marketing specialists to create concise guides, tutorials, landing pages, printed materials, and various other assets. We are seeking a passionate, creative individual with exceptional writing, video production, and public speaking abilities to join our marketing team and contribute to our content creation efforts.

We are seeking a talented Mid-Level Java Developer with a background in React to join our dynamic team at XITE. Your primary responsibility will be backend development for our proprietary Media Asset Management and curation systems, utilized by our Music Team.About XITEXITE is dedicated to sharing our passion for music videos with the world, allowing audiences to 'see' their music as well as hear it. Our mission is to provide the best music video experience globally. Based in Amsterdam, XITE currently serves over 100 million households across North America and Europe.XITE offers exceptional music video experiences through our four main products:Global & International (Europe & North America)FAST (Free Ad-Supported Streaming TV): A rapidly expanding global platform that offers themed music channels directly on smart TVs, featuring 26 genre and decade-based channels across Europe and North America.Interactive TV App: This app is available on smart TVs across various countries in Europe and North America, offering over 200 curated playlists for a personalized viewing experience.The NetherlandsLinear Television: Our brand's origins trace back to 2008, available specifically in the Netherlands via all major cable and fiber providers.XITE Music: An extensive collection of 51 non-stop audio channels exclusively available for viewers in the Netherlands.The Role and TeamAs a member of XITE's Content Technology Team, you will help maintain our music video catalog from ingestion to distribution across our interactive app, FAST channels, and linear TV. You will join a close-knit team of three engineers and two product team members, collaborating with our music team of around 10 individuals to create the best music video content experience in Europe and North America.In this role, you will take pride in maintaining well-functioning systems rather than high-volume daily tasks. Our pipelines manage a catalog of hundreds of thousands of music videos, and once established, they require minimal oversight. Your focus will be on improving these systems thoughtfully and building internal tools that enhance efficiency.

JetBrains has developed tools for software teams since 2000. By automating routine checks and corrections, JetBrains products help developers focus on building and shipping software. The goal: make development more productive and creative. Role overview This Backend Customer Success Engineer role centers on supporting engineering teams as they adopt Kotlin for backend development. The position focuses on helping organizations successfully bring Kotlin into production environments. What you will do Guide organizations through the process of moving from Java to Kotlin, assisting with migration, integration, and scaling. Troubleshoot technical challenges that arise during the transition and support teams as they progress from initial experimentation to stable production use. Work with potential users to clarify how Kotlin adoption works and help design migration plans that fit their specific needs. Locations Amsterdam, Netherlands Berlin, Germany Munich, Germany Prague, Czech Republic Remote, Germany

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).

JetBrains is seeking an AI Lead focused on Python tools. This position centers on advancing AI technologies across the company’s product suite, with the goal of improving both user experience and product capabilities. Role overview The AI Lead will guide the development and integration of AI features into JetBrains products. The role involves direct oversight of AI project initiatives and regular collaboration with teams from various disciplines. Expect to play a key part in shaping technical direction and ensuring that Python-powered solutions continue to set a high standard in the industry. What you will do Oversee AI-focused projects from conception through implementation Work closely with engineers, designers, and product managers to align AI features with product goals Drive innovation by applying Python expertise to create and refine AI solutions Locations This role is open to candidates based in Amsterdam, Belgrade, Berlin, Limassol, London, Madrid, Munich, Paphos, Prague, remote within Germany, Warsaw, and Yerevan.

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.