Freelance Backend Developer

Highlights Location: Fully Remote (CET hours preferred) Compensation: €5,100 - €6,300 per month + stock options Language: Russian-speaking team About Fundraise Up At Fundraise Up, we are revolutionizing the way nonprofits receive donations. Our innovative platform facilitates a fast, seamless, and user-friendly donation experience, empowering organizations to harness the power of generosity. Our technology processes tens of millions of dollars in donations monthly, focusing on enhancements that lead to faster load times, higher conversion rates, and accessible design. Trusted by renowned nonprofits like UNICEF and the Alzheimer’s Association, and with a stellar 4.9/5 rating on leading software review platforms, our product is recognized for both its effectiveness and quality. A Truly Global Product We serve nonprofit organizations across North America, the UK, Australia, and Europe in the enterprise sector. Our robust product ecosystem includes a modern checkout experience, customizable widgets, donor and organization portals, admin tools, and multiple internal applications. Our backend technology stack features Node.js (Koa, NestJS) and MongoDB. The frontend utilizes Webpack, Vue.js, and React, with a significant portion of the codebase written in TypeScript. For high-volume messaging and background processing, we implement Kafka and Bull (Redis). Analytics are managed through ClickHouse, while Elasticsearch is utilized for search functionalities. The Team We are a diverse team of over 160 professionals, including more than 80 engineers, distributed across Spain, Poland, Portugal, Georgia, Armenia, Serbia, Turkey, and Cyprus. Our team members typically possess 5-10+ years of experience, fostering a culture of technical curiosity and knowledge sharing. Despite our size, we maintain a close-knit team environment where every contribution is valued, and collaboration is key. We prioritize strong engineering practices and a product-first mindset, hosting biweekly engineering forums to share insights and celebrate achievements. Join a team where quality, mentorship, and mutual respect are at the forefront. About the Role As a Backend Developer, you will be instrumental in architecting the core engine that drives our global platform. You will tackle complex challenges within a high-load, distributed system, constructing and scaling the infrastructure that processes millions in donations. This role goes beyond maintenance; it involves active development and innovation.

Jobgether is hiring a Senior Node.js Backend Developer in Poland for a partner company. This role joins an experienced engineering team focused on building secure, scalable backend systems that power digital financial services worldwide. Key Responsibilities Design and develop backend solutions with Node.js for global financial products Build and maintain mission-critical services and APIs supporting real-time transactions Architect infrastructure for distributed systems to ensure reliability Optimize backend performance while maintaining strong security standards Collaborate with engineers across different regions Contribute to advancing next-generation financial technology Requirements Proven experience in backend architecture and distributed systems Advanced skills in Node.js development Ability to tackle complex technical challenges Interest in scaling secure, real-time applications Self-motivated and comfortable working with autonomy in a remote-first environment Located in Poland Work Environment This is a remote-first position. The team emphasizes independence, responsibility, and continuous learning. Senior Node.js Backend Developers here work closely with talented colleagues and play a direct role in shaping products used by customers around the world.

Role overview Fundraise Up seeks a Product Analyst to support product decisions and enhance the user experience. This is a remote role available to candidates based in Poland. What you will do Examine product performance by reviewing data and key metrics Work with teams across the company to help drive product development Monitor market trends and highlight areas for growth Collect and interpret user feedback to suggest improvements Share insights that help shape strategic choices Location This position is fully remote within Poland.

Join Hostinger as a Backend Software Engineer specializing in Node.js in a fully remote position! In this role, you will be responsible for developing high-performance backend solutions that support our web applications and services. Collaborate with a dynamic team of developers and contribute to exciting projects that empower our users around the globe.

Role Overview We are seeking a dynamic Product Owner to spearhead the delivery of Elements, our robust UI component system that enhances the donation experience at Fundraise Up. Your focus will be on product delivery and ensuring operational excellence. You will translate strategic growth initiatives into actionable, production-ready features while maintaining product stability and guaranteeing reliable delivery for enterprise clients. Key Responsibilities Convert strategic initiatives from the Product Management team into well-defined product specifications. Oversee the complete delivery lifecycle from specifications through development, QA, and final release. Manage a prioritized product backlog that aligns with the company's overarching goals. Address client-critical issues and facilitate resolutions to deal-breaking challenges. Collaborate with Go-To-Market teams by providing product knowledge and innovative solutions. Drive internal product enhancements and reduce technical debt effectively. Ensure that the product remains stable, scalable, and of the highest quality. Expected Time Allocation: Strategic Features (from PM) — 50% Internal Improvements — 35% GTM & Deal Breakers — 15%

Join Our Team!At Xebia, we are dedicated to fostering a culture of innovation and professional growth. For over 19 years, we have been delivering cutting-edge digital solutions to clients in various industries around the globe. Notable brands such as UPS, McLaren, Aviva, and Deloitte trust us with their digital transformation journeys.Our enthusiasm for Cloud-based solutions is unparalleled, driven by our partnerships with leading Cloud providers including Amazon Web Services (AWS), Microsoft Azure, and Google Cloud Platform (GCP). We proudly became the first AWS Premier Consulting Partner in Poland.Previously known as PGS Software, we joined the Xebia Group in 2021, aligning with a network of companies committed to making a significant impact in the tech world.Xebia embodies innovation and technological excellence, with a mission to be recognized as the authority in our domain. Our commitment to detail, knowledge sharing, and nurturing individual potential sets us apart.We are eager to learn more about you!Send us your resume to initiate a conversation and become a part of the #Xebia community!Your Responsibilities:Design, develop, and maintain scalable backend services and APIs utilizing Node.js and TypeScript, ensuring exceptional performance and reliability.Architect and implement RESTful and/or GraphQL APIs and microservices-based solutions to meet complex business requirements.Collaborate with cross-functional teams to define technical solutions, enhance system architecture, and advocate for engineering best practices.Optimize database schemas and queries, guaranteeing data integrity, security, and performance across both relational and non-relational databases.Support DevOps and cloud initiatives through engagement with CI/CD pipelines, containerization, monitoring, and cloud infrastructure, facilitating smooth deployments and system observability.

Join Our Team!At Xebia, we cultivate expertise and innovation. For nearly two decades, we've been delivering cutting-edge digital solutions to clients across various industries around the globe, partnering with renowned brands like UPS, McLaren, Aviva, Deloitte, and many more.Our passion lies in Cloud technologies. We proudly partner with the leading Cloud providers, including Amazon Web Services (AWS), Microsoft Azure, and Google Cloud Platform (GCP), and were the first AWS Premier Consulting Partner in Poland.Previously known as PGS Software, we became part of the Xebia Group in 2021, a network of companies committed to transforming the technology landscape.Xebia epitomizes innovation, a talented workforce, and technical excellence, offering us the chance to work on groundbreaking global projects.Our mission is succinct: to be recognized as the authority in our domain.What sets us apart? It's our attention to detail, commitment to knowledge, and belief in people’s potential, fostering the growth of every team member. To truly appreciate our culture and values, we invite you to visit us!Now that we've shared our story, we look forward to learning about you.Send us your resume and start the journey with #Xebia!Your Role:Design, develop, and maintain scalable backend services and APIs using Node.js and TypeScript, ensuring optimal performance and reliability.Architect and implement RESTful and/or GraphQL APIs along with microservices-based solutions to address complex business needs.Collaborate with cross-functional teams to define technical solutions, enhance system architecture, and uphold engineering best practices.Optimize database schemas and queries, ensuring data integrity, security, and performance across both relational and non-relational databases.Support DevOps and cloud initiatives by engaging with CI/CD pipelines, containerization, monitoring, and cloud infrastructure, ensuring seamless deployments and system observability.

MasterBorn is seeking a Junior Backend Developer with a focus on Node.js. This position is open to candidates based in Wrocław or those who prefer to work remotely. Role overview This role centers on developing server-side applications using Node.js. Junior Backend Developers at MasterBorn collaborate with experienced colleagues and contribute to a range of technical projects. The position offers a chance to build practical skills and gain exposure to modern backend technologies. What you will do Work on backend features and APIs using Node.js Collaborate with other developers to deliver project goals Contribute to the development and maintenance of server-side applications Requirements Interest in backend development and Node.js Willingness to learn and grow as part of a team Ability to work from Wrocław or remotely

Join Our Team!Xebia is a renowned tech innovator where professionals thrive. For nearly two decades, we have been creating cutting-edge digital solutions for a diverse range of clients worldwide, including industry giants like UPS, McLaren, Aviva, and Deloitte.Our passion lies in Cloud technologies, underscored by partnerships with leading Cloud providers such as Amazon Web Services (AWS), Microsoft Azure, and Google Cloud Platform (GCP). Notably, we were the first AWS Premier Consulting Partner in Poland.Previously known as PGS Software, we became part of the Xebia Group in 2021, a collection of companies committed to making a significant impact in technology.Xebia embodies innovation, a talented workforce, and technological mastery, allowing us to work on groundbreaking global projects. Our mission can be summed up in one word: Authority. We aspire to be acknowledged as the preeminent authority in our domain.What sets us apart? It's our attention to detail, commitment to knowledge, and belief in individual potential—fostering the growth of every team member. We invite you to come and see the difference for yourself!We look forward to learning more about you. Send us your resume and let's begin the conversation!

About FlosumFlosum is a successful, self-sustaining B2B SaaS organization that has developed a premier Salesforce-native DevSecOps, Data Protection, and Security platform. Our solutions are utilized by Fortune 500 companies across some of the most highly regulated sectors globally, including financial services, healthcare, government, and insurance.Unlike many startups, we have achieved profitability through our own efforts, establishing ourselves as a credible player in enterprise software. As a Salesforce Summit Partner and recipient of the Innovation Award, we are proud to stand alongside industry leaders.Our platform is built entirely on Salesforce, catering to enterprises that prioritize security, compliance, and reliability.Role OverviewWe are in a rapid expansion phase, enhancing our product offerings, improving platform capabilities, and increasing our delivery speed. We seek seasoned Node.js developers who can take ownership of substantial components of our architecture and deliver production-quality code that our enterprise customers rely on daily.This is not a mere augmentation role. You will collaborate closely with engineering leaders, product managers, and the CEO, ensuring your decisions impact the product significantly, your insights are valued, and your craftsmanship is evident to the customers who depend on our platform.Your ContributionsCreate high-performance backend services and APIs that drive enterprise-level SaaS applicationsDevelop scalable, secure Node.js microservices and integrations within the Salesforce ecosystemDesign modern front-end experiences with Vue.js and TypeScript tailored for demanding enterprise usersEstablish CI/CD pipeline tools, automation frameworks, and developer productivity infrastructureImplement real-time data processing and event-driven architectures for handling sensitive enterprise data on a large scale

Join our innovative team at dev2 as a Backend Software Engineer where you will play a crucial role in developing scalable backend solutions. Your expertise will help shape our technology stack and improve system performance. You will collaborate with cross-functional teams to design, implement, and maintain high-quality applications.

Join our dynamic team at Renmoney as a Java Backend Developer, where you will contribute to our core engineering teams, including Banking, Loans, Core Tech Platform, and Cards. Our teams are focused on developing high-impact, backend-heavy systems that drive essential financial products and internal platforms.At Renmoney, we prioritize engineering excellence—not only in delivery speed but also in system quality and the artistry of software development. We are cultivating a collaborative engineering culture that values clear communication, thoughtful architecture, rigorous testing, and teamwork.Our tech stack includes: Java • Spring Boot • AWS (EKS) • MySQL • Kafka • Redis • Grafana • Prometheus.

Join our dynamic team at HOS247 LLC as a Senior Full-Stack Developer in a fully remote capacity. We are on the lookout for talented developers who are eager to enhance and innovate our existing suite of products. In this role, you will work closely with our Chief Technology Officer, collaborating on developing and refining solutions that drive our business forward.The ideal candidate will possess a robust background in full-stack development, with a minimum of three years of hands-on experience in Angular 2+ and Node.js.

We are seeking a highly skilled Senior AI-Enabled Architect with over 7 years of experience to join our dynamic team at Altoros. In this pivotal role, you will analyze intricate project scopes, explore realistic optimization opportunities through AI-driven development practices utilizing a multi-agent approach, and actively contribute to technical implementation when necessary.This position encompasses two primary dimensions:Acting as a hands-on architect capable of deconstructing complex requirements, designing resilient backend architectures, and participating directly in the implementation process.Leveraging structured, practical experience in AI-first application development—creating effective workflows around LLM-based tools to enhance delivery efficiency safely.The core focus of this role is to drive project-level impact: assessing new opportunities (particularly those involving extensive integrations or high complexity), identifying secure optimization strategies, and, as required, leading or contributing to the execution of those solutions.This is a hands-on, execution-oriented technical position for someone who has effectively applied AI-first development practices in real-world production environments and possesses a solid business understanding of software development projects.

Join Our Team at HSP GroupHSP Group stands at the forefront of global expansion services, dedicated to simplifying the complexities of international operations. We offer a comprehensive suite of solutions in legal entity setup, global HR, payroll, compliance, tax, and advisory, empowering our clients to scale efficiently while minimizing risks.As a pioneering startup in the dynamic field of global expansion management, we pride ourselves on our commitment to innovation, delivery excellence, and customer satisfaction. You will be an integral part of our small yet highly skilled team, contributing directly to our success.About Gateway HRGateway HR is our specialized HRIS platform tailored for global expansion management, featuring seamless integration with our flagship Gateway GXM platform. This enables functionalities such as automated payslip generation, smart contract management, and effortless cross-border compliance.Our ecosystem already incorporates AI-driven document recognition and serverless architecture on Azure, alongside a diverse range of integrated tools for HR, entity management, and compliance.Your RoleThis is a fully remote role. We are seeking a Lead Backend Engineer to spearhead the technical vision for Gateway HR and enhance its integration with GXM. You will engage in hands-on platform development while leading external development teams—refining the architecture, innovating new features, and upholding HSP's engineering standards across the codebase.This position is not solely managerial; you will actively code, review pull requests, challenge architectural choices, and launch features while setting high standards for the team.

Highlights Location: Fully Remote (CET hours preferred) Language: Russian-speaking team; English proficiency at B2+ level required About Fundraise Up At Fundraise Up, we are pioneering a global fundraising platform designed to make donations to nonprofits quick, effortless, and accessible to everyone. Our technology facilitates millions of dollars in donations each month worldwide. We prioritize innovation that yields tangible results: enhanced load speeds, improved conversion rates, global payment support, and a design that prioritizes accessibility. Our platform is trusted by some of the world’s foremost nonprofits, including UNICEF and the Alzheimer’s Association, alongside various global NGOs. With an outstanding 4.9/5 rating across leading software review platforms, we are recognized not only for our impact but also for the superior quality of our product. A Truly Global Product We serve the enterprise segment, catering to nonprofit organizations across North America, the UK, Australia, and Europe. We are constructing a vast and intricate product ecosystem that serves nonprofits, donors, and partners globally. Our platform features a modern checkout experience, customizable widgets (each operating as a standalone SPA), donor, organization, and partner portals, admin tools, and various internal applications. Our backend utilizes Node.js (Koa, NestJS) and MongoDB, while our frontend stack comprises Webpack, Vue.js, and React, with nearly all code developed in TypeScript. For high-volume messaging and background processing, we employ Kafka (for millions of events) and Bull (Redis). Analytics data is stored in ClickHouse, with Elasticsearch utilized for search functionalities. The Team Our distributed team consists of over 160 product professionals, including more than 80 engineers. Our members are primarily situated in Spain, Poland, Portugal, Georgia, Armenia, Serbia, Turkey, and Cyprus. Many developers possess 5 to 10+ years of experience, fostering a culture rich in technical curiosity and knowledge sharing. Despite our considerable scale, we maintain a focused team environment where every task counts, and every voice matters. We value thoughtful collaboration, robust engineering practices, and a product-centric mindset. Biweekly engineering forums allow us to share learnings and celebrate technical achievements. You will join a team that prioritizes quality, mentorship, and mutual respect. About the Role We are in search of a seasoned Team Lead to join our Elements team. In this role, you will guide the development of embedded "elements"—a suite of widgets that nonprofits can integrate into their websites to enhance donation processes.

Join our dynamic team as a Senior TypeScript/Node.js Developer and contribute to a cutting-edge advertising platform designed for the Swedish market. In this role, you will leverage your extensive experience in TypeScript and Node.js to develop robust and scalable applications that enhance user engagement and drive business growth.As part of our innovative company, you’ll collaborate with cross-functional teams to deliver high-quality software solutions while utilizing the latest technologies in a supportive and creative environment.

Join our dynamic team at Lingarogroup as a Backend Developer! In this role, you will be responsible for designing, implementing, and maintaining server-side applications and databases, ensuring high performance and responsiveness to requests from the front-end. You will work closely with front-end developers to integrate user-facing elements with server-side logic.We are looking for someone who possesses a strong understanding of backend technologies, is highly motivated, and thrives in a collaborative environment.

Role OverviewAs a key member of our Lab team, you will drive the exploration of pioneering product opportunities that challenge the status quo. We are looking for a Product Manager who can identify, validate, and mitigate risks associated with high-uncertainty projects. Your focus will be on innovative solutions that may not directly align with our current offerings but have the potential to redefine the future of digital fundraising.Key ResponsibilitiesIdentify and pursue technology-driven opportunities, leveraging advancements in AI, data analytics, and platform capabilities.Transform vague signals and emerging technologies into actionable product hypotheses.Maintain an exploration backlog that includes risks, assumptions, and learning objectives.Experiment Design and EvaluationFrame experiments around the most significant assumptions and define explicit kill criteria prior to development.Choose the appropriate level of fidelity in prototypes to validate concepts quickly and effectively.