Senior Full-Stack Engineer (ASP.NET / React)

🏢 Summary: Senior Full-Stack Engineer (.NET & React) role focused on building scalable APIs and microservices powering music and content experiences across a global fitness platform. The position involves designing distributed backend systems, supporting real-time music playback, and collaborating cross-functionally to deliver high-quality features at scale. Hybrid work model in Warsaw with competitive salary and comprehensive benefits. 🗂️ Requirements: 5+ years of professional software development experience, Strong knowledge of C#, Strong knowledge of .NET ecosystem, Experience building and maintaining RESTful APIs, Understanding of asynchronous programming, Understanding of multithreading, Experience with NoSQL databases, Familiarity with microservices architecture, Working knowledge of React, Vue.js or similar frontend frameworks, Experience with CI/CD pipelines, Experience with automated testing, Understanding of DevOps principles, Understanding of Agile methodologies, English communication skills 📃 Skills: C#, .NET, REST, React, Vue, MongoDB, AWS, S3, SQS, Lambda, Microservices, CI/CD, Docker, Kubernetes, RabbitMQ, NServiceBus 🏢 Description: We are hiring on behalf of our client, a global innovator in fitness and wellness technology. Their mission is to empower people to live fit, strong, long, and happy lives by delivering integrated experiences to millions of members anytime, anywhere. We are looking for a Senior Full-Stack Engineer (.NET & React) to join the Content Platform team, focused on building systems that power music-related experiences across the product ecosystem. In this role, you will design and develop APIs and backend services that support everything from instructor class planning to real-time music playback during workouts. This is a hands-on engineering role with strong ownership, where you will work on distributed systems, collaborate across teams, and directly impact user-facing features at scale. Key takeaways: Stack : C#, .NET, REST APIs, React/Vue, MongoDB, AWS (S3, SQS, Lambda), microservices Salary : 23 000 PLN - 28 000 PLN gross on the Contract of Employment Working model : Hybrid - 3 days/week from the office Location : ul. Grzybowska 60, Warsaw Recruitment process : A call with MOTIFE Recruiter Panel interviews with the team (coding, architecture, and cross-collaboration interviews, Hiring Manager meeting) Responsibilities: Backend Development & Architecture Design, build, and maintain scalable APIs and microservices supporting content and music-related features Develop systems for managing music catalogs, class planning tools, and platform integrations Ensure high performance, reliability, and scalability of backend services Technical Excellence Write clean, maintainable, and well-tested code with a focus on long-term sustainability Drive best engineering practices, including CI/CD, automated testing, logging, and monitoring Continuously improve system architecture while avoiding unnecessary complexity Collaboration & Delivery Partner closely with Product, Design, and QA to deliver high-quality features Actively participate in architecture discussions, code reviews, and technical planning Translate UI/UX requirements into reliable backend solutions Engineering Culture Contribute to a culture of code quality, ownership, and continuous improvement Promote practices such as refactoring, pair programming, and iterative development Support knowledge sharing and help evolve engineering standards across the team Requirements: Technical Expertise 5+ years of professional software development experience Strong knowledge of C# and .NET ecosystem Experience building and maintaining RESTful APIs Solid understanding of asynchronous programming and multi-threading Experience with NoSQL databases (e.g., MongoDB) Familiarity with microservices architecture Frontend & Platform Awareness Working knowledge of React, Vue.js, or similar frontend frameworks Understanding of system integration and API-driven development Engineering Practices Experience with CI/CD pipelines, automated testing, and DevOps principles Understanding of Agile and Lean development methodologies Strong focus on code quality, maintainability, and scalability Collaboration & Mindset Strong communication skills in English Ability to work effectively in cross-functional teams Comfortable working in fast-paced, evolving environments Nice to Have Experience with Docker and Kubernetes Familiarity with AWS services (S3, SQS, Lambda) Experience with messaging systems (e.g., NServiceBus, RabbitMQ) What we offer: 100% paid medical care Multisport Creative tax (KUP) Home office allowance MacBook Pro

🏢 Summary: Senior Full-Stack Engineer (.NET & React) role focused on building scalable APIs and microservices powering music-related experiences across a global fitness platform. The position involves designing distributed systems, supporting real-time music playback, and delivering high-impact user-facing features at scale. It is a hands-on role with strong ownership and cross-functional collaboration. 🗂️ Requirements: 5+ years of professional software development experience, Strong knowledge of C#, Strong knowledge of .NET ecosystem, Experience building and maintaining RESTful APIs, Experience with asynchronous programming, Experience with multithreading, Experience with NoSQL databases, Experience with MongoDB, Familiarity with microservices architecture, Working knowledge of React or Vue.js, Experience with CI/CD pipelines, Experience with automated testing, Understanding of DevOps principles, Understanding of Agile methodologies, English proficiency for technical communication 📃 Skills: C#, .NET, REST, React, Vue, MongoDB, AWS, S3, SQS, Lambda, Microservices, CI/CD, Docker, Kubernetes, RabbitMQ, NServiceBus 🏢 Description: We are hiring on behalf of our client, a global innovator in fitness and wellness technology. Their mission is to empower people to live fit, strong, long, and happy lives by delivering integrated experiences to millions of members anytime, anywhere. We are looking for a Senior Full-Stack Engineer (.NET & React) to join the Content Platform team, focused on building systems that power music-related experiences across the product ecosystem. In this role, you will design and develop APIs and backend services that support everything from instructor class planning to real-time music playback during workouts. This is a hands-on engineering role with strong ownership, where you will work on distributed systems, collaborate across teams, and directly impact user-facing features at scale. Key takeaways: Stack : C#, .NET, REST APIs, React/Vue, MongoDB, AWS (S3, SQS, Lambda), microservices Salary : 23 000 PLN - 28 000 PLN gross on the Contract of Employment Working model : Hybrid - 3 days/week from the office Location : ul. Grzybowska 60, Warsaw Recruitment process : A call with MOTIFE Recruiter Panel interviews with the team (coding, architecture, and cross-collaboration interviews, Hiring Manager meeting) Responsibilities: Backend Development & Architecture Design, build, and maintain scalable APIs and microservices supporting content and music-related features Develop systems for managing music catalogs, class planning tools, and platform integrations Ensure high performance, reliability, and scalability of backend services Technical Excellence Write clean, maintainable, and well-tested code with a focus on long-term sustainability Drive best engineering practices, including CI/CD, automated testing, logging, and monitoring Continuously improve system architecture while avoiding unnecessary complexity Collaboration & Delivery Partner closely with Product, Design, and QA to deliver high-quality features Actively participate in architecture discussions, code reviews, and technical planning Translate UI/UX requirements into reliable backend solutions Engineering Culture Contribute to a culture of code quality, ownership, and continuous improvement Promote practices such as refactoring, pair programming, and iterative development Support knowledge sharing and help evolve engineering standards across the team Requirements: Technical Expertise 5+ years of professional software development experience Strong knowledge of C# and .NET ecosystem Experience building and maintaining RESTful APIs Solid understanding of asynchronous programming and multi-threading Experience with NoSQL databases (e.g., MongoDB) Familiarity with microservices architecture Frontend & Platform Awareness Working knowledge of React, Vue.js, or similar frontend frameworks Understanding of system integration and API-driven development Engineering Practices Experience with CI/CD pipelines, automated testing, and DevOps principles Understanding of Agile and Lean development methodologies Strong focus on code quality, maintainability, and scalability Collaboration & Mindset Strong communication skills in English Ability to work effectively in cross-functional teams Comfortable working in fast-paced, evolving environments Nice to Have Experience with Docker and Kubernetes Familiarity with AWS services (S3, SQS, Lambda) Experience with messaging systems (e.g., NServiceBus, RabbitMQ) What we offer: 100% paid medical care Multisport Creative tax (KUP) Home office allowance MacBook Pro

🏢 Summary: Senior Full-Stack Engineer role focused on designing and building scalable APIs and microservices that power music-related experiences across a global fitness platform. The position combines backend development in .NET with frontend collaboration in React/Vue, working on distributed systems and real-time features. It involves strong ownership, architectural influence, and delivering high-impact user-facing solutions at scale. 🗂️ Requirements: 5+ years of professional software development experience, Strong knowledge of C#, Strong knowledge of .NET ecosystem, Experience building and maintaining RESTful APIs, Understanding of asynchronous programming, Experience with multithreading, Experience with NoSQL databases, Experience with MongoDB, Familiarity with microservices architecture, Working knowledge of React or Vue.js, Experience with CI/CD pipelines, Experience with automated testing, Understanding of DevOps principles, Understanding of Agile methodologies, Strong focus on code quality and scalability, Professional English communication skills 📃 Skills: C#, .NET, REST, React, Vue, MongoDB, AWS, S3, SQS, Lambda, Microservices, CI/CD, Docker, Kubernetes, RabbitMQ, NServiceBus 🏢 Description: We are hiring on behalf of our client, a global innovator in fitness and wellness technology. Their mission is to empower people to live fit, strong, long, and happy lives by delivering integrated experiences to millions of members anytime, anywhere. We are looking for a Senior Full-Stack Engineer (.NET & React) to join the Content Platform team, focused on building systems that power music-related experiences across the product ecosystem. In this role, you will design and develop APIs and backend services that support everything from instructor class planning to real-time music playback during workouts. This is a hands-on engineering role with strong ownership, where you will work on distributed systems, collaborate across teams, and directly impact user-facing features at scale. Key takeaways: Stack : C#, .NET, REST APIs, React/Vue, MongoDB, AWS (S3, SQS, Lambda), microservices Salary : 23 000 PLN - 28 000 PLN gross on the Contract of Employment Working model : Hybrid - 3 days/week from the office Location : ul. Grzybowska 60, Warsaw Recruitment process : A call with MOTIFE Recruiter Panel interviews with the team (coding, architecture, and cross-collaboration interviews, Hiring Manager meeting) Responsibilities: Backend Development & Architecture Design, build, and maintain scalable APIs and microservices supporting content and music-related features Develop systems for managing music catalogs, class planning tools, and platform integrations Ensure high performance, reliability, and scalability of backend services Technical Excellence Write clean, maintainable, and well-tested code with a focus on long-term sustainability Drive best engineering practices, including CI/CD, automated testing, logging, and monitoring Continuously improve system architecture while avoiding unnecessary complexity Collaboration & Delivery Partner closely with Product, Design, and QA to deliver high-quality features Actively participate in architecture discussions, code reviews, and technical planning Translate UI/UX requirements into reliable backend solutions Engineering Culture Contribute to a culture of code quality, ownership, and continuous improvement Promote practices such as refactoring, pair programming, and iterative development Support knowledge sharing and help evolve engineering standards across the team Requirements: Technical Expertise 5+ years of professional software development experience Strong knowledge of C# and .NET ecosystem Experience building and maintaining RESTful APIs Solid understanding of asynchronous programming and multi-threading Experience with NoSQL databases (e.g., MongoDB) Familiarity with microservices architecture Frontend & Platform Awareness Working knowledge of React, Vue.js, or similar frontend frameworks Understanding of system integration and API-driven development Engineering Practices Experience with CI/CD pipelines, automated testing, and DevOps principles Understanding of Agile and Lean development methodologies Strong focus on code quality, maintainability, and scalability Collaboration & Mindset Strong communication skills in English Ability to work effectively in cross-functional teams Comfortable working in fast-paced, evolving environments Nice to Have Experience with Docker and Kubernetes Familiarity with AWS services (S3, SQS, Lambda) Experience with messaging systems (e.g., NServiceBus, RabbitMQ) What we offer: 100% paid medical care Multisport Creative tax (KUP) Home office allowance MacBook Pro

🏢 Summary: Senior Full-stack Engineer role focused on building and scaling a modern B2B SaaS platform for subscription-based e-commerce. The position involves end-to-end feature delivery, architectural decisions, and improving system scalability and reliability. High-impact role with strong ownership over technical direction and product evolution. 🗂️ Requirements: 7+ years engineering experience in complex systems, Strong system design skills, Experience designing scalable architectures, Full-stack development experience, Experience building SaaS platforms, Experience with e-commerce systems 📃 Skills: JavaScript, TypeScript, SaaS, Architecture, Scalability, Reliability, APIs, Ecommerce, Payments, Cloud 🏢 Description: Senior Full-stack Engineer Our client is building a modern B2B SaaS platform that enables businesses to launch and scale subscription-based models for physical and digital products. The product sits at the intersection of e-commerce, payments, and developer tooling, with a strong focus on extensibility and developer experience. The team is lean, senior, and highly experienced, backed by strong investors and industry advisors. They operate with high autonomy, fast execution, and strong ownership culture. Role We are looking for a Senior Full-stack Engineer to help shape the next evolution of the platform. You will work across architecture, product, and infrastructure, focusing on scalability, reliability, and developer experience. This is a high-impact role where you will influence both technical direction and product decisions. Responsibilities Build and evolve a scalable SaaS platform Design and deliver new features end-to-end Improve performance, reliability, and system architecture Collaborate with product, design, and growth teams Requirements 7+ years of engineering experience in complex systems Strong architectural and system design skills Ability to choose appropriate technologies per problem Experience working in cross-functional teams Strong communication in Polish and English Startup mindset: ownership, speed, adaptability Experience with e-commerce platforms is a plus Offer High-impact role in a senior engineering team with real product ownership and influence. Competitive salary plus ESOP, fully remote work (Poland), regular team offsites, and modern tooling including MacBook Pro and AI credits. Direct access to founders, investors, and advisors.

🏢 Summary: Senior Fullstack Software Engineer role focused on building scalable, cloud-native applications with a strong backend emphasis (70% backend, 30% frontend). The position involves designing distributed, event-driven systems on AWS, developing REST APIs, and contributing across the full stack using Node.js, TypeScript, React, and Next.js. The engineer will drive architectural decisions, scalability, and technical direction while collaborating with cross-functional teams in a US-aligned remote environment. 🗂️ Requirements: Strong experience as Senior Software Engineer in product-focused environments, Advanced backend development with Node.js and TypeScript, Experience building and consuming REST APIs, Frontend development experience with React and TypeScript, Experience with AWS or other cloud platforms, Strong knowledge of distributed and scalable system design, Experience with MySQL and PostgreSQL databases, Experience with event-driven architectures, Experience with queuing or messaging systems, Ability to write clean, maintainable, scalable code, Strong debugging and problem-solving skills, Availability to work overlapping US hours 📃 Skills: Node.js, TypeScript, React, Next.js, AWS, REST, MySQL, PostgreSQL, SQL, APIs, Microservices, Event-driven, Messaging, Queues, Cloud, Distributed-systems 🏢 Description: Fullstack Senior Software Engineer Location: Remote We are looking for a talented Senior Fullstack Software Engineer to join a high-performing product engineering team focused on building scalable, modern cloud-native applications. This role is best suited to an experienced engineer who is stronger on the backend (approximately 70% backend / 30% frontend) and enjoys designing robust distributed systems while still being comfortable contributing across the full stack. You will play a key role in shaping technical direction, building scalable event-driven platforms, and contributing to product thinking - not just delivering code. We are looking for someone with strong ownership, accountability, and the ability to think about the wider business and customer impact of the solutions they build. This position requires alignment with US-based teams, and so the working hours must overlap. What You'll Be Doing Designing, building, and maintaining scalable backend services using Node.js and TypeScript Developing and supporting modern frontend applications using React and Next.js Building robust RESTful APIs and backend integrations Contributing to distributed, cloud-native systems running on AWS Designing and implementing event-driven architectures and queue-based systems Working with SQL databases including MySQL and PostgreSQL Driving engineering best practices, scalability, reliability, and performance improvements Collaborating closely with Product, Engineering, and stakeholders to shape technical solutions Taking ownership of features and systems throughout the full software lifecycle Mentoring engineers and contributing to technical discussions and architectural decisions Required Skills & Experience Strong experience as a Software Engineer / Senior Software Engineer in modern product-focused environments Excellent backend development experience with: Node.js TypeScript REST APIs React TypeScript Experience building applications in AWS cloud environments (or other cloud platforms) Strong understanding of scalable and distributed system design MySQL PostgreSQL Proven experience building event-driven architectures and working with queuing/messaging systems (highly important) Ability to write clean, maintainable, and scalable code Strong problem-solving and debugging skills What We're Looking For Strong product mindset - someone who thinks beyond just delivering tickets and understands the "why" behind engineering decisions Ownership and accountability for technical delivery and outcomes Ability to contribute to architectural direction and scalability initiatives Comfortable working in fast-paced, collaborative engineering environments Passion for building high-quality, scalable software products Strong communication and stakeholder collaboration skills

🏢 Summary: Senior Full Stack Engineer role focused on building AI-powered enterprise product features across frontend and backend systems in a fully onsite Warsaw office. The position involves owning the full development lifecycle, collaborating with product and design teams, and improving performance, reliability, and user experience. The company offers a modern AI-focused engineering environment, B2B contract, stock options, and opportunities to work with enterprise-scale AI solutions. 🗂️ Requirements: Senior-level experience building production web applications, Frontend experience with React, Frontend experience with TypeScript or similar frameworks, Backend experience designing APIs and backend services, Experience working with full-stack architectures and data flows, Ability to make technical decisions balancing scope, quality, and delivery time, Security-focused mindset and experience handling sensitive data, Experience collaborating with engineering, product, and design teams, Experience using AI tools in software development workflows, Availability to work onsite in Warsaw 5 days a week 📃 Skills: React, TypeScript, Python, Node.js, APIs, AI, Claude, OpenAI, Codex, GitHub, Copilot 🏢 Description: Please note: This role requires working from our office in Warsaw city centre 5 days a week . This is a fully on-site position , and remote or hybrid work is not available . About us We believe that businesses are moving toward AI-powered work, and we are building a platform for this future. Many AI agents cannot handle complex business tasks. We created a platform that organizes company policies, workflows, and business knowledge into one AI data model. This helps AI agents make accurate decisions and deliver reliable results at scale. We already work with well-known enterprise customers such as Glovo, Nespresso, and HelloFresh. Our platform supports thousands of users and processes real production data. Customers trust us with important business knowledge because we provide a secure and reliable solution with SOC2, HIPAA-ready security practices, and strong integrations. Job description We are looking for a Senior Full Stack Engineer who enjoys building complete product solutions from start to finish. In this role, you will understand customer needs, design the right technical solution, build new features, and improve them after release. You will work across both frontend and backend, taking ownership of the whole development process - from the first idea to production. The position is based in Warsaw and requires working from the office. Responsibilities Build and deliver product features across both frontend and backend. Turn product ideas into practical technical solutions with the right scope and priorities. Work across the full technology stack, including user interfaces, backend logic, APIs, and data flows. Work closely with product managers and designers, even when requirements are still changing. Improve usability, performance, reliability, and overall product quality. Monitor applications after release, analyze logs and system data, and continue improving the product. Use AI tools every day to improve development speed, workflows, and engineering processes. Maintain high standards for code quality, testing, and long-term ownership. Requirements Strong senior-level experience building and delivering production web applications. Strong frontend skills with React, TypeScript, or a similar modern web framework. Good backend experience designing APIs, backend services, and data flows. Strong product thinking with the ability to improve user experience and simplify complex workflows. Good judgment when making technical decisions and balancing scope, quality, and delivery time. A security-focused approach and experience handling sensitive data. Good communication skills and experience working with engineering, product, and design teams. Experience using AI tools as part of your daily software development work. Nice to have Experience building AI-powered products such as chat applications, search, recommendation systems, workflows, or AI agents. Experience with Python, Node.js, or both. Experience leading product areas with a high level of ownership. Good understanding of web performance, accessibility, and production quality. What we offer B2B contract and company stock options. MacBook Pro. Modern technology stack and the opportunity to contribute to open-source projects. An AI-focused development environment with tools such as Claude Code, OpenAI Codex, and GitHub Copilot. Our values Our leadership team has strong experience in AI, knowledge management, and enterprise SaaS. We have received more than $60 million in funding and have been recognized by Gartner as a Cool Vendor. Our work is guided by these values: Quality – We care about excellent work and high standards in everything we build. Momentum – We take initiative, share ideas, and keep moving forward. Accountability – We take responsibility for our work and give honest, respectful feedback. Hard work – We believe success comes from teamwork, dedication, and consistent effort. Learning agility – We stay curious, learn from mistakes, and continue improving. Adapt and thrive – We welcome change and see challenges as opportunities to grow. Win together – We work as one team, communicate openly, and support our shared goals.

🏢 Summary: A fully remote Full Stack Engineer role in a late-stage product company building a new engineering team in Poland. The position focuses on developing scalable, production-grade applications using TypeScript, React, and Node.js across the stack. Engineers collaborate cross-functionally to deliver end-to-end features with strong emphasis on quality, performance, and reliability. 🗂️ Requirements: Strong proficiency in TypeScript, Experience with React, Experience with Node.js or server-side TypeScript, Understanding of testing practices, Experience with CI/CD, Experience with version control, Ability to work in a collaborative, fast-paced environment 📃 Skills: TypeScript, React, Node.js, CI/CD, Git, APIs, Microservices, AWS, GCP, Azure, Testing 🏢 Description: A late-stage (Series D), well-funded product company is building a brand-new, fully-remote engineering team in Poland. We're looking for talented Full Stack Engineers who can build high-quality, scalable applications using TypeScript , React , and modern backend frameworks. You'll work closely with product, design, and other engineers to deliver features end-to-end. While financial markets experience is a plus, it is not required - strong engineering fundamentals matter more. We are open to candidates who specialize in only front-end or only back-end development, as well as true full-stack engineers. What You'll Do Design, build, and maintain production-grade applications using TypeScript across the stack. Develop intuitive, performant user interfaces using React and modern front-end tooling. Build and maintain backend services, APIs, and integrations (Node.js / TypeScript). Collaborate with product managers and designers to translate requirements into technical solutions. Write clean, testable, maintainable code with strong attention to performance and reliability. Participate in code reviews, architecture discussions, and continuous improvement initiatives. Troubleshoot issues across the stack and contribute to a culture of engineering excellence. Required Skills Strong proficiency in TypeScript . Experience with React for front-end development. Experience with Node.js , server-side TypeScript, or similar backend frameworks. Solid understanding of modern software engineering practices: testing, CI/CD, version control, code reviews. Ability to work in a fast-paced, collaborative environment. Nice to Have Experience working in financial markets , fintech, or trading systems. Familiarity with cloud platforms (AWS, GCP, Azure). Experience with microservices, event-driven architectures, or distributed systems. Exposure to data visualization libraries or real-time data applications. Experience with performance optimization on either the front-end or back-end.

🏢 Summary: Senior Full Stack Developer role focused on architecting and delivering high-performance web applications using React and Node.js. The position involves leading system design, building scalable front-end and back-end solutions, and overseeing cloud-based deployments and DevOps processes. The role includes technical ownership of microservices, APIs, databases, and application performance in a hybrid Warsaw-based setup. 🗂️ Requirements: 7+ years full stack development experience, 2+ years in senior or technical lead role, Expert-level React.js with Hooks and Redux, Advanced JavaScript ES6+ proficiency, Strong Node.js and Express.js experience, Experience designing REST or GraphQL APIs, Experience with OAuth, JWT, sessions, RBAC, Database design and optimization with PostgreSQL, MySQL, or MongoDB, Hands-on Docker experience, Experience with AWS, Azure, or GCP, CI/CD pipeline management experience, Proficiency with Git workflows, Bachelor’s or Master’s in Computer Science or related field 📃 Skills: React, Redux, JavaScript, HTML5, CSS3, Node.js, Express, GraphQL, REST, OAuth, JWT, RBAC, PostgreSQL, MySQL, MongoDB, Docker, Kubernetes, AWS, Azure, GCP, Git, CI/CD, Webpack, Babel, Vite 🏢 Description: 🧩 About the Company Our client is a rapidly growing US-based technology firm with global operations. With a strong commitment to innovation and quality engineering, the company is building a new engineering hub in Warsaw. This is your opportunity to join a high-performing team and play a pivotal role in developing next-generation digital solutions for the private capital markets. 📍 Location & Setup Start remotely and transition to a hybrid model based in Warsaw (3 days/week in the office in the coming months). 🧠 The Role: Senior Full Stack Developer (React & Node.js) We’re looking for an expert-level Senior Full Stack Developer with at least 7 years of professional experience in designing, architecting, and delivering high-performance web applications. You will take ownership of complex technical challenges across both the front-end and back-end, drive architectural decisions, and provide technical leadership and mentorship within the software development lifecycle. 🔧 Key Responsibilities Technical Leadership: Architect and develop scalable, responsive UIs with React.js, Redux, and modern JavaScript (ES6+). System Design: Design, build, and scale advanced server-side applications, microservices architecture, and RESTful/GraphQL APIs with Node.js and Express. Data Architecture: Lead database design, optimization, and integration strategies (PostgreSQL, MySQL, or MongoDB). Quality Assurance: Define testing strategies, write robust unit/integration tests, and establish efficient debugging protocols for the team. DevOps & Deployment: Oversee and optimize CI/CD pipelines, containerization using Docker, and cloud deployments. Agile Mentorship: Lead agile collaboration with product managers, designers, and engineers, while mentoring mid-level and junior developers. Performance: Proactively monitor system performance, identify bottlenecks, and maintain high-availability production-grade applications. Standards: Establish and maintain comprehensive technical documentation and coding standards. 📌 What We’re Looking For Front-End: Expert-level experience with React.js, Hooks, Redux, and complex component-based architecture. Deep mastery of HTML5, CSS3, and ES6+. Advanced configuration and optimization experience with build tools like Webpack, Babel, or Vite. Back-End: Senior-level proficiency in Node.js & Express.js for enterprise applications. Extensive API design and architecture experience (GraphQL highly preferred, alongside REST). Deep understanding and implementation experience with advanced security and authentication protocols: OAuth, JWT, sessions, and RBAC. Databases & DevOps: Proven experience in scaling and optimizing relational and non-relational databases (PostgreSQL, MySQL, or MongoDB). Solid hands-on experience with Docker; Kubernetes experience is highly advantageous. Demonstrated experience designing and deploying applications on cloud platforms (AWS, Azure, or GCP). Advanced proficiency with Git workflows and driving Agile/Scrum methodologies. 🎓 Qualifications Bachelor’s or Master’s in Computer Science or a related field. 7+ years of hands-on experience in full stack development. 2+ years of experience in a senior or technical lead capacity. Proven track record of architecting, deploying, and maintaining high-traffic production applications. 💡 Soft Skills Strategic, analytical thinker and highly effective problem-solver. Strong technical leadership, team collaboration, and cross-functional communication skills. Self-motivated with excellent time management and the ability to drive projects autonomously. Passion for continuous learning, adopting new technologies, and sharing knowledge with the team. 🎁 What’s Offered Competitive salary up to $6,200 USD/month. Hybrid remote role with 3 days form office in the heart of Warsaw Generous Paid Time Off (PTO). Comprehensive full benefits package. The unique chance to shape the technical foundation of a new engineering hub and lead high-impact projects. A supportive, innovation-driven work environment that values technical excellence.

🏢 Summary: B2B contract role for a Full-Stack Software Engineer to develop and maintain backend services in C#/.NET and frontend components in React within a dynamic, international project environment. The position involves building scalable solutions, integrating REST APIs, and supporting implementations with effective problem-solving. Remote work with long-term project engagement. 🗂️ Requirements: Proficiency in C# and .NET for scalable services development, Experience with React.js and React Query, Experience with Azure SQL and MS SQL, Experience building RESTful APIs with ASP.NET Core (OpenAPI), Knowledge of CI/CD processes and Agile methodologies, Experience with Azure DevOps or GitHub, English at minimum B2 level 📃 Skills: C#, .NET, React, ReactQuery, AzureSQL, MSSQL, REST, ASP.NET, OpenAPI, CI/CD, AzureDevOps, GitHub, Azure 🏢 Description: We are currently looking for a Full-Stack Software Engineer for our client, a world-leading provider of digital solutions and applications, with a particular focus on the energy, maritime, and healthcare markets. If working in a dynamic environment is something you’re comfortable with and you use the tech stack listed below on a daily basis, this opportunity is for you! Key responsibilities Developing advanced backend solutions in C# Creating and maintaining frontend components Preparing technical documentation Supporting implementations through quick and effective problem-solving Balancing changing priorities with ongoing development work Ideal candidate profile Proficient in .NET for building scalable services React.js, React Query Azure SQL, MS SQL RESTful APIs with ASP.NET Core (OpenAPI Standard) Knowledge of Agile methodologies and CI/CD processes (Azure DevOps, GitHub) English on B2 level nice to have: Experience with Azure (App Services, Azure Functions, Key Vault, Storage Accounts, Entra ID) Experience using AI-based development tools (Microsoft Copilot, GitHub Copilot) Conditions Employment Type: B2B contract Salary: Depends on your experience Work Model : Remote work model (possible 2–4 business trips per year to the office in Poland or Norway) Benefits : private medical care, sport card, life insurance Project duration: Project start March/April, with a duration of at least until the end of the year Recruitment steps Phone call with Recruiter Client interview Feedback and decision

🏢 Summary: B2B contract role for a Senior Full-Stack Engineer to build and own features end-to-end, from Java/Spring backend services and data models to React-based frontend interfaces. The position involves contributing to shared UI components and backend architecture, performing cross-stack code reviews, and working in a cloud-native environment. 🗂️ Requirements: Strong backend experience with Java 21, Proficiency in Spring and Spring Boot, Experience with Hibernate, Solid frontend experience with JavaScript and TypeScript, Strong knowledge of React and Redux Toolkit, Good understanding of relational databases, especially MariaDB, User-level or higher Linux skills, Confident use of Git workflows, Ability to write well-tested, maintainable code, Advanced technical English, Experience with Kubernetes and cloud-native platforms, Ability to effectively use AI coding assistants and LLM tools 📃 Skills: Java, Spring, SpringBoot, Hibernate, JavaScript, TypeScript, React, Redux, MariaDB, SQL, Linux, Git, Kubernetes, AI, LLM 🏢 Description: Join our client's team as a Senior Full-Stack Engineer! RESPONSIBILITIES Own features end-to-end — from API and data model on the backend to the UI on the frontend Build and maintain backend services in Java, and rich interfaces in React Contribute to our shared UI component library and backend architecture alike Take part in code reviews across the stack — backend, frontend, and the glue in between REQUIREMENTS Strong backend skills in Java 21 with Spring / Spring Boot and Hibernate Solid frontend experience with JavaScript, TypeScript, React, and Redux Toolkit Good grasp of relational databases, especially MariaDB Linux skills at user level or above, plus confident Git workflows You write well-tested, maintainable code on both sides of the stack Advanced technical English for design, review, and documentation\ Proven experience with cloud-native platforms such as Kubernetes Comfortable using AI tools (coding assistants, LLMs) as part of your daily workflow — and the judgment to know when to trust them and when to think for yourself NICE TO HAVE Experience building software for telecommunication systems Knowledge of protocols like IPv4/6, DNS, BGP, DHCP, SR, and ZTP Data visualization libraries — Cytoscape.js, react-chartjs-2, MapLibre, or similar Storybook, mono-repo tooling (Lerna), or Webpack experience Automation tools such as Ansible or Terraform Understanding of Linux and Kubernetes networking (routing, iptables, CNI) WHAT DO WE OFFER ON THIS PROJECT? Cooperation based on a B2B contract and rate: 160-180 PLN/hour Hybrid work from Kraków (1 times a week in the office) The support of a dedicated mentor. In the relationship, we focus on direct communication. When you join speedapp, you will be put in touch with a dedicated mentor who will make sure that you enjoy working with us and with the client Events and integration meetings, as well as participation in various initiatives, e.g., sports Access to the benefits offering (medical care, Multisport card) WHAT DOES THE RECRUITMENT PROCESS LOOK LIKE? Application: Apply and submit your CV. After the application review, the recruiter will contact selected candidates by phone. Screening: Have a conversation with a speedapp recruiter about your experience. Next steps: The speedapp recruiter will explain the recruitment process for the specific position. The speedapp recruiter will stay in touch with you throughout the entire process. ABOUT SPEEDAPP At speedapp, we believe that an organization is only as good as the people who make it up. We are a team of IT experts and other professionals working for our clients around the world (including Israel, Austria, USA). We go far beyond the HR category. We build IT teams and also help manage them. 👉 10 years of experience 👉 +100 clients worldwide +300 hires per year 💎 We have won the prestigious "Forbes Diamonds" award four times (2022, 2023, 2024, 2025). We are a member of the European Fast Growth Icons network and FinTech Poland. We are ranked 18th among the 100 fastest growing companies 2023 by Clutch. DO YOU HAVE ANY QUESTIONS? Contact the recruiter responsible for this process directly. Karolina Kizowska Senior IT Delivery Consultant karolina.kizowska@speedapp.pl +48 608 487 448