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

🏢 Summary: B2B contract for a Mid/Senior FullStack Engineer to modernize and migrate legacy .NET applications to a modular, cloud-native Azure architecture in the banking sector. The role combines backend development in .NET with frontend work in React, focusing on refactoring legacy systems, building scalable APIs, and implementing CI/CD and observability practices. Hybrid work model with strong influence on architectural decisions and cloud migration. 🗂️ Requirements: 5+ years of commercial experience with C# and .NET (Framework and .NET Core/6+), Strong proficiency in EF Core and MSSQL (query tuning, transactions, indexing), Commercial experience with React and TypeScript, Experience building and securing REST APIs (authentication, versioning, validation), Familiarity with Azure services (App Service, Functions, SQL, Service Bus, Storage), Experience with automated testing (unit, integration, contract, E2E), Experience with CI/CD pipelines (Azure DevOps or GitHub Actions), Ability to work with legacy .NET codebases (ASP.NET MVC, Razor, WPF, WinForms), English at B2+ level 📃 Skills: C#, .NET, .NETCore, .NET6, .NET8, EFCore, MSSQL, T-SQL, React, TypeScript, REST, Azure, AppService, AzureFunctions, AzureSQL, ServiceBus, AzureStorage, xUnit, Jest, Playwright, Cypress, Git, AzureDevOps, GitHubActions, ASP.NET, MVC, Razor, WPF, WinForms, DDD, CleanArchitecture 🏢 Description: We are looking for FullStack Engineer (.NET & React) Location: Kraków / Hybrid (7 days in the office per month) Contract Type: B2B Contract Seniority: Mid / Senior About the Project Join a high-impact modernization initiative for a leading player in the banking sector . We are transforming a portfolio of approximately a dozen .NET applications and MSSQL databases into a modular, cloud-native Azure architecture. As a FullStack Engineer, you will play a dual role: evolving existing production services (including legacy UI and desktop components) while systematically extracting business logic to re-implement it into a modern, scalable ecosystem. This is a unique opportunity to influence the transition from monolithic architectures to high-performance, distributed cloud services. Your Responsibilities Design & Development: Build backend services and APIs using .NET 6/8 following Clean Architecture and DDD patterns. Frontend Evolution: Develop and maintain React + TypeScript frontends, managing the incremental migration from legacy UI modules. Modernization: Read, refactor, and extract complex business logic from legacy .NET codebases and T-SQL stored procedures. Quality Assurance: Write and maintain comprehensive automated tests (Unit, Integration, Contract, and E2E). DevOps & Observability: Create CI/CD pipelines (Azure DevOps/GitHub Actions) and instrument services for deep observability (metrics, logs, distributed traces). Collaboration: Participate in domain modeling, architecture discussions, and Agile ceremonies with Architects and Product Owners. Skills & Experience We Require Experience: 5+ years of commercial experience with C# and the .NET ecosystem (both Framework and .NET Core/6+). Database Expertise: Strong proficiency in EF Core and MSSQL (including query tuning, transactions, and indexing). Frontend: Solid production experience with React and TypeScript. Web Services: Practical experience in building and securing REST APIs (Auth, Versioning, Validation). Cloud: Familiarity with Azure services (App Service, Functions, SQL, Service Bus, Storage). Testing & Tooling: Experience with xUnit, Jest, and Playwright/Cypress, as well as disciplined Git practices. Legacy Handling: The ability to read and reason about legacy codebases (ASP.NET MVC, Razor, WPF, or WinForms). Communication: English at a B2+ level for technical documentation and team collaboration. Nice to Have Experience with Infrastructure as Code (Terraform or Bicep). Knowledge of Docker and Kubernetes (AKS). Background in migrating monoliths to microservices. Azure Developer Associate certification. What We Offer Impact: Real influence on the architecture and the cloud migration roadmap. Autonomy: Direct collaboration with Tech Leads and Architects in a flat structure. Modern Stack: Opportunity to work with the latest .NET versions (6/8) and React. Efficiency: Fast technical onboarding with immediate access to repos, CI/CD pipelines, and monitoring tools. Flexible Hybrid Model: Remote-first approach with only 7 planned days in the Kraków office per month. Benefits : Luxmed and Multisport Card

🏢 Summary: Full Stack Development Lead role focused on delivering end-to-end solutions using React and C# .NET Core in a cloud-driven, microservices-based environment. The position combines hands-on development with architectural input and technical leadership in a fully remote B2B setup. The role involves close collaboration with cross-functional teams and contribution to modern DevOps and data workflows. 🗂️ Requirements: Proven full-stack experience with React, TypeScript, C# .NET Core, Strong knowledge of microservices architecture, Understanding of distributed systems, Experience with CI/CD pipelines, Experience with cloud platforms (Azure preferred), Experience with containers, Familiarity with DevOps practices, Ability to design APIs and event-driven components 📃 Skills: React, TypeScript, C#, .NET, Microservices, CI/CD, Azure, Docker, DevOps, PySpark, PowerBI, APIs 🏢 Description: Start Date: ASAP / Within 1 Month / Flexible Work Model: 100% remote Contract Type: B2B (160-180 PLN/h + VAT) We are looking for an experienced Full Stack Development Lead who will take ownership of end‑to‑end solutions across React and C# .NET Core while contributing to technical direction and supporting a collaborative engineering culture. This role is ideal for a strong Senior Full Stack Developer who is ready to expand into leadership responsibilities, work closely with cross‑functional teams, and influence architectural decisions in a modern, cloud‑driven environment. Expectations Proven experience in full‑stack development using React, TypeScript, and C# .NET Core. Good understanding of microservices , distributed systems, and CI/CD pipelines. Exposure to cloud platforms (Azure preferred), containers, and modern DevOps practices. Experience with data workflows (pyspark) or BI solutions (Power BI) is a strong advantage. Ability to collaborate with technical and business stakeholders and take initiative in solution design. Responsibilities Contribute to the design and delivery of full‑stack applications using React and C# .NET Core. Support architectural discussions around microservices, APIs, and event‑driven components. Collaborate with data engineers on pyspark workflows and Power BI reporting enhancements. Promote engineering best practices, code quality, and maintainable development patterns. Mentor team members and support planning, collaboration, and continuous improvement efforts. What We Offer Medicover healthcare package Multisport card Access to an e-learning platform Group life insurance

🏢 Summary: Mid-level Full-stack Developer role focused on building and maintaining web and mobile applications using React and .NET technologies. The position involves developing scalable backend services, microservices, and SEO-friendly frontends integrated with CMS, within a multinational Agile environment. The role combines frontend, backend, cloud, and DevOps responsibilities with regular team collaboration. 🗂️ Requirements: 2–4 years experience as FullStack Developer, .NET 8/10 proficiency, C# proficiency, Strong React knowledge, JavaScript proficiency, TypeScript proficiency, HTML5 knowledge, CSS3 knowledge, Experience with RESTful APIs, Experience with Git, Experience with Microsoft Azure (Functions, Durable Functions, CosmosDB, ServiceBus, Application Insights), Experience with CI/CD pipelines, Experience with Agile methodologies, Communicative English (B2+) 📃 Skills: .NET, C#, React, JavaScript, TypeScript, HTML5, CSS3, REST, Git, Azure, Functions, CosmosDB, ServiceBus, ApplicationInsights, CI/CD, ReactNative, Expo, Sanity, GROQ, Redux, RxJS, Tanstack, Sentry, Firebase, Analytics 🏢 Description: Join Our Team as a Full-stack Developer (React, C#)! We are seeking a talented Mid FullStack Developer proficient in .NET and React to join our team. As part of our company culture, we value collaboration and regular in-person interactions. Our team meets every two months in our Poznań office for informal gatherings to connect, share ideas, and strengthen teamwork in a relaxed setting. You will work in multinational environment and will be responsible for designing and implementing software solutions, utilizing both front-end and back-end technologies. This role requires strong problem-solving skills, excellent communication abilities, and a passion for delivering high-quality code. Ready to take the next step in your career? Apply now and join us! Key Responsibilities: • Design and develop SEO-friendly web application, based on React and TypeScript and integrated with Sanity CMS. • Contributing to a mobile application using React Native, TypeScript and Expo . • Build and maintain microservices to enhance the web experience, including features like roadside assistance, car repair bookings, and membership management. • Develop robust and scalable backend systems using .NET 8/10, Azure ServiceBus, Functions, CosmosDB and more. • Utilize Sentry for error monitoring and Google Analytics/Firebase to track user behaviour and optimize performance. Requirements : Proven experience (2-4 years) as a FullStack Developer Proficiency in .NET (preferably .NET 8/10), C# Strong understanding of front-end technologies, including React, JavaScript, TypeScript, HTML5, and CSS3 Practical knowledge of clean-code principles and patterns, drive to write clean, testable and maintainable code Experience with RESTful APIs and Web Services Knowledge of version control systems, such as Git Excellent problem-solving and analytical skills Familiarity with Microsoft Azure platform (Functions and Durable Functions, CosmosDb, ServiceBus, Application Insights) Experience with DevOps approach and CI/CD pipelines Strong communication and interpersonal skills, communicative English (B2+) Experience with Agile development methodologies Nice to have: Experience in working with Sanity CMS and GROQ query language (or any other headless CMS) Familiarity with Figma or similar tools At least basic knowledge about Server Side Rendering and libraries like: Redux, RxJS, Tanstack Experience in working with mobile apps and practical knowledge of React Native, Expo, Expo Application Services Knowledge of microservices architecture and software integration patterns We offer: Conference/workshop budget of approximately 10000 PLN!- the budget renews every year and can be used for conferences, workshops, training programs, certifications, studies, or other development initiatives. "Fabresikowe": one-time 1000 PLN bonus to create your work space more comfortable and more tailored to your needs! Relaxing office massages In-house trainings Team events Frequent company events Free breakfast every day Free beverages, fresh fruit, snacks Chill out room English and Norwegian classes

🏢 Summary: Full-Stack Developer role on a long-term, enterprise-scale banking project, delivering web solutions using .NET and React in a regulated environment. The position involves end-to-end development, API integration, and database optimization within a global technology team. Work is fully remote from Poland with collaboration on complex financial systems. 🗂️ Requirements: 3+ years of full-stack development experience, Proficiency in C# and ASP.NET Core, Experience with .NET Web API, Strong knowledge of React including state management and component architecture, Experience with HTML5, CSS3, JavaScript or TypeScript, Experience designing and integrating RESTful APIs, Strong SQL Server skills including queries and stored procedures, Experience with Entity Framework, Knowledge of design patterns and database normalization, Experience with Azure DevOps for source control and CI/CD, Understanding of application security, performance, and scalability best practices, Bachelor's degree in Computer Science or related field 📃 Skills: C#, .NET, ASP.NETCore, WebAPI, React, HTML5, CSS3, JavaScript, TypeScript, REST, SQL, SQLServer, EntityFramework, AzureDevOps 🏢 Description: We are looking for an experienced Full-Stack Developer to join a long-term project for one of the world's leading professional services organizations. You will work within a global technology team delivering solutions for a UK-based banking client in a regulated, enterprise-scale environment. Location: 100% Remote (Poland) with occasional visits to Warsaw office Client: Global professional services firm, banking & financial services sector, UK Requirements 3+ years of experience in full-stack development, with proficiency in most of the following: C#, ASP.NET Core, .NET Web API React — state management, component architecture HTML5, CSS3, JavaScript / TypeScript RESTful API design and integration SQL Server — queries, stored procedures, functions, views Entity Framework Design patterns and database normalization Azure DevOps for source control and CI/CD Application security, performance, and scalability best practices Bachelor's degree in Computer Science or related field Nice to Have Azure Cloud Services and cloud-native architecture SFTP and encryption/secure file transfer protocols Experience with vendor software integration and custom interfaces Responsibilities Design, develop, and maintain web applications using .NET (C#, ASP.NET Core) and React Build responsive user interfaces with HTML, CSS, JavaScript, and React Develop and consume RESTful APIs to connect client-side and server-side components Implement and optimize data storage using SQL Server (stored procedures, functions, views) Perform coding, debugging, testing, and troubleshooting throughout the development lifecycle Maintain and enhance existing systems, fixing complex bugs and escalating risks where needed Capture detailed requirements from stakeholders and translate them into technical specifications Ensure adherence to coding standards, design patterns, and security best practices Collaborate with vendor teams and third-party integrations Monitor emerging technologies and contribute ideas for continuous improvement We Offer 100% remote work from Poland Occasional team meetups in Warsaw Long-term project with a prestigious international client Exposure to enterprise-scale banking solutions B2B Contract Private medical care ( Luxmed ) MultiSport sports card

🏢 Summary: Senior Fullstack Engineer role focused on .NET and React development for enterprise-grade applications, driving scalable backend services and modern UI solutions. The position involves leading architectural decisions, enhancing CI/CD processes, and improving application performance and user experience. Candidates will contribute across the full SDLC while supporting digital transformation initiatives. 🗂️ Requirements: Minimum 7 years of professional experience in .NET production development, Strong experience with C# and Web API, Hands-on experience with React, Advanced SQL skills with SQL Server and T-SQL, Experience with DevOps practices and CI/CD processes, Solid understanding of SDLC, Fluent English (written and spoken), Legal right to work in the European Union 📃 Skills: .NET, C#, WebAPI, React, SQL, SQLServer, T-SQL, DevOps, CI/CD, Docker, Kubernetes 🏢 Description: Unleash innovation — shape the future of enterprise applications. Krakow-based opportunity with hybrid work model. As a Senior Fullstack Engineer – .NET and React Development , you will be working for our client, a leader in enterprise software solutions, dedicated to delivering robust, scalable, and innovative digital tools. Your expertise will drive the development of cutting-edge applications that empower businesses worldwide, supporting their digital transformation journeys. Your main responsibilities: Implement solutions following best Design Patterns to ensure maintainability and scalability Analyze requirements to fully understand solutions and recommend improvements for optimal performance Lead UI enhancements and improvements to boost user experience and application stability Actively participate in DevOps automation and improve the CI/CD lifecycle processes Manage changes through the entire service management lifecycle, ensuring seamless updates Contribute to software architecture design and technical decision-making Develop and prototype applications to validate concepts and designs Provide exceptional customer support by addressing and resolving issues promptly Communicate effectively with clients to understand needs and deliver tailored solutions You're ideal for this role if you have: A minimum of 7 years of professional experience in production application development within .NET ecosystems, including front-end (preferably React) and DevOps practices Proficiency in C# and Web API development, with a focus on scalable, secure backend services Strong hands-on experience with React, building dynamic, responsive web applications Advanced SQL skills, particularly with SQL Server, including T-SQL scripting, query optimization, and performance tuning Solid understanding of the SDLC, from requirement gathering to deployment and maintenance Exceptional problem-solving abilities and an eye for detail to ensure high-quality deliverables It is a strong plus if you have: (optional) Certifications in cloud or DevOps tools Experience with containerization (e.g., Docker, Kubernetes) Language Required for the role: Fluent English (written and spoken) Eligibility for the role: Only candidates with an existing legal right to work in the European Union will be considered for this role. #MAKEYourCareerBETTER Interested? Apply now and include your CV (preferably in English) along with a statement confirming your consent to the processing and storage of your personal data.

🏢 Summary: Senior Fullstack Engineer role focused on building and enhancing scalable enterprise applications using .NET and React within a hybrid Krakow-based setup. The position involves leading UI improvements, contributing to architecture and DevOps automation, and delivering high-quality, secure backend and frontend solutions. The engineer drives full SDLC activities, from design and development to deployment and support. 🗂️ Requirements: Minimum 7 years of professional experience in .NET production application development, Strong experience with React for frontend development, Proficiency in C# and Web API development, Advanced SQL Server skills including T-SQL and query optimization, Experience with DevOps practices and CI/CD processes, Solid understanding of SDLC, Fluent English, Legal right to work in the European Union 📃 Skills: .NET, C#, WebAPI, React, SQL, SQLServer, T-SQL, CI/CD, DevOps, Docker, Kubernetes 🏢 Description: Unleash innovation — shape the future of enterprise applications. Krakow-based opportunity with hybrid work model. As a Senior Fullstack Engineer – .NET and React Development , you will be working for our client, a leader in enterprise software solutions, dedicated to delivering robust, scalable, and innovative digital tools. Your expertise will drive the development of cutting-edge applications that empower businesses worldwide, supporting their digital transformation journeys. Your main responsibilities: Implement solutions following best Design Patterns to ensure maintainability and scalability Analyze requirements to fully understand solutions and recommend improvements for optimal performance Lead UI enhancements and improvements to boost user experience and application stability Actively participate in DevOps automation and improve the CI/CD lifecycle processes Manage changes through the entire service management lifecycle, ensuring seamless updates Contribute to software architecture design and technical decision-making Develop and prototype applications to validate concepts and designs Provide exceptional customer support by addressing and resolving issues promptly Communicate effectively with clients to understand needs and deliver tailored solutions You're ideal for this role if you have: A minimum of 7 years of professional experience in production application development within .NET ecosystems, including front-end (preferably React) and DevOps practices Proficiency in C# and Web API development, with a focus on scalable, secure backend services Strong hands-on experience with React, building dynamic, responsive web applications Advanced SQL skills, particularly with SQL Server, including T-SQL scripting, query optimization, and performance tuning Solid understanding of the SDLC, from requirement gathering to deployment and maintenance Exceptional problem-solving abilities and an eye for detail to ensure high-quality deliverables It is a strong plus if you have: (optional) Certifications in cloud or DevOps tools Experience with containerization (e.g., Docker, Kubernetes) Language Required for the role: Fluent English (written and spoken) Eligibility for the role: Only candidates with an existing legal right to work in the European Union will be considered for this role. #MAKEYourCareerBETTER Interested? Apply now and include your CV (preferably in English) along with a statement confirming your consent to the processing and storage of your personal data.

🏢 Summary: Senior Fullstack Engineer role focused on building and enhancing scalable enterprise applications using .NET and React in a hybrid Krakow-based setup. The position involves leading UI improvements, contributing to architecture and DevOps automation, and delivering high-quality backend and frontend solutions. You will drive end-to-end development from design to deployment while ensuring performance, stability, and maintainability. 🗂️ Requirements: Minimum 7 years experience in .NET application development, Strong experience with React for frontend development, Proficiency in C# and Web API, Advanced SQL Server and T-SQL skills, Experience with CI/CD and DevOps practices, Understanding of SDLC, Experience with design patterns and software architecture, Fluent English, Legal right to work in EU 📃 Skills: .NET, C#, React, WebAPI, SQL, SQLServer, T-SQL, CI/CD, DevOps, SDLC, Docker, Kubernetes 🏢 Description: Unleash innovation — shape the future of enterprise applications. Krakow-based opportunity with hybrid work model. As a Senior Fullstack Engineer – .NET and React Development , you will be working for our client, a leader in enterprise software solutions, dedicated to delivering robust, scalable, and innovative digital tools. Your expertise will drive the development of cutting-edge applications that empower businesses worldwide, supporting their digital transformation journeys. Your main responsibilities: Implement solutions following best Design Patterns to ensure maintainability and scalability Analyze requirements to fully understand solutions and recommend improvements for optimal performance Lead UI enhancements and improvements to boost user experience and application stability Actively participate in DevOps automation and improve the CI/CD lifecycle processes Manage changes through the entire service management lifecycle, ensuring seamless updates Contribute to software architecture design and technical decision-making Develop and prototype applications to validate concepts and designs Provide exceptional customer support by addressing and resolving issues promptly Communicate effectively with clients to understand needs and deliver tailored solutions You're ideal for this role if you have: A minimum of 7 years of professional experience in production application development within .NET ecosystems, including front-end (preferably React) and DevOps practices Proficiency in C# and Web API development, with a focus on scalable, secure backend services Strong hands-on experience with React, building dynamic, responsive web applications Advanced SQL skills, particularly with SQL Server, including T-SQL scripting, query optimization, and performance tuning Solid understanding of the SDLC, from requirement gathering to deployment and maintenance Exceptional problem-solving abilities and an eye for detail to ensure high-quality deliverables It is a strong plus if you have: (optional) Certifications in cloud or DevOps tools Experience with containerization (e.g., Docker, Kubernetes) Language Required for the role: Fluent English (written and spoken) Eligibility for the role: Only candidates with an existing legal right to work in the European Union will be considered for this role. #MAKEYourCareerBETTER Interested? Apply now and include your CV (preferably in English) along with a statement confirming your consent to the processing and storage of your personal data.

🏢 Summary: Senior Full Stack Engineer role focused on building and optimizing React/TypeScript frontends and ASP.NET Core backend services supporting treasury workflows. The position involves designing scalable REST APIs, improving performance across the stack, and working with large datasets in production systems. Hybrid work model in Warsaw with strong emphasis on engineering best practices and reliability. 🗂️ Requirements: 5+ years of experience building production systems, Strong experience with C# and .NET ecosystem, Strong experience with ASP.NET Core, Strong experience with React, Strong experience with TypeScript, Experience designing and building REST APIs, Experience handling large datasets efficiently, Hands-on experience with ag-Grid, Highcharts or similar libraries, Understanding of authentication and authorization mechanisms, Experience with relational databases, Experience with performance optimization 📃 Skills: C#, .NET, ASP.NETCore, React, TypeScript, REST, ag-Grid, Highcharts, SQL, CI/CD, Authentication, Authorization, Serialization 🏢 Description: Senior Full Stack Engineer (.NET / React) Warsaw, hybrid, 3 days per week from the office. Responsibilities Build and enhance frontend applications and backend services supporting treasury workflows. Develop React/TypeScript single‑page applications and reusable UI components. Design and implement ASP.NET Core REST APIs with scalable pagination and filtering models. Optimize performance across the stack, including APIs, serialization, rendering, and large data grids. Collaborate with business stakeholders, quant teams, and product managers to deliver user‑focused solutions. Drive engineering best practices including code reviews, testing, CI/CD, and production support. Investigate production issues and improve observability and platform reliability. Mentor engineers and contribute to technical growth within the Warsaw team. Requirements 5+ years of software engineering experience building production systems. Strong experience with C#/.NET ecosystem and ASP.NET Core . Strong frontend experience with React and TypeScript. Experience building REST APIs and handling large datasets efficiently. Hands‑on experience with ag‑Grid, Highcharts, or similar UI/data visualization libraries. Strong understanding of authentication, authorization, and serialization mechanisms. Experience working with relational databases and performance optimization. Strong communication skills and ability to work directly with business stakeholders. Nice to Have Experience in treasury, trading, or financial systems. Strong product mindset and UX awareness.

🏢 Summary: Senior .NET Engineer role focused on modernizing and enhancing an insurance platform using Azure and microservices architecture. The position involves full-stack development, backend services in .NET Core, cloud deployment, and DevOps automation. The engineer will contribute to scalable, secure solutions and AI-driven initiatives within a cloud-native environment. 🗂️ Requirements: 5+ years of full-stack web application development, Proficiency in .NET Core (8–10), Experience with Entity Framework and Dapper, Experience building REST and XML APIs, Advanced MS SQL including query optimization and stored procedures, Experience with Azure App Service and Azure Container Apps, Hands-on experience with microservices architecture, Experience with Docker and containerization, Experience implementing CI/CD using Azure DevOps or similar tools, Familiarity with ReactJS, Vue.js or Angular, Knowledge of SignalR and WebSockets, Experience with GitHub Copilot, Understanding of secure coding practices 📃 Skills: .NET, C#, Azure, MS, SQL, Entity, Framework, Dapper, REST, XML, ReactJS, Vue.js, Angular, Docker, Microservices, CI/CD, Azure, DevOps, GitHub, Terraform, ARM, SignalR, WebSockets, Copilot 🏢 Description: We are seeking a skilled Senior .NET Engineer with expertise in Azure and full-stack development to join an exciting project for our client, a US-based insurance provider. This role focuses on enhancing the client's insurance platform through modernization and leveraging cutting-edge technologies. Responsibilities Work on the development and modernization of an insurance platform towards a modular and microservices architecture under Azure Implement backend services using .NET Core (8–10), Entity Framework and Dapper to ensure performance and scalability Build and integrate RESTful and XML-based APIs for application functionality and interoperability Develop advanced database solutions using MS SQL including query optimization and stored procedures Create dynamic responsive user interfaces using ReactJS or Vue.js Architect microservices and leverage Docker for efficient deployment and scalability Manage application deployment on Azure cloud platforms such as Azure App Service and Azure Container Apps Apply DevOps best practices for CI/CD, release management and automation with tools like Azure DevOps, Azure Repos, GitHub, Azure ARM or Terraform Contribute to AI-driven initiatives through the adoption of AI tools like GitHub Copilot Ensure adherence to secure coding standards throughout development processes Incorporate technologies for real-time communication including SignalR and WebSockets Work autonomously, manage time effectively and consistently meet project deadlines Collaborate with cross-functional teams to document technical solutions and specifications Requirements 5+ years of experience building full-stack web applications and delivering end-to-end solutions Proficiency in .NET Core (8–10), Entity Framework, Dapper, REST and XML-based APIs Advanced MS SQL skills including query optimization and stored procedure development GitHub Copilot experience and willingness to contribute to AI adoption within the team Expertise in Azure cloud platforms including Azure App Service and Azure Container Apps Familiarity with modern web frameworks such as ReactJS, Vue.js or Angular Hands-on experience with microservices architecture, Docker and containerization Skills in implementing DevOps practices for CI/CD and automation using Azure DevOps, Azure Repos, GitHub, Azure ARM or Terraform Awareness of SignalR and WebSockets for real-time communication Strong focus on secure coding practices and project deadline management Adaptability to work independently while effectively collaborating in a team environment and clearly documenting solutions We offer/Benefits We gather like-minded people: Engineering community of industry professionals Friendly team and enjoyable working environment Flexible schedule and opportunity to work remotely within Poland Chance to work abroad for up to 60 days annually Business-driven relocation opportunities We provide growth opportunities: Outstanding career roadmap Leadership development, career advising, soft skills, and well-being programs Certification (GCP, Azure, AWS) Unlimited access to LinkedIn Learning, Get Abstract, Cloud Guru English classes We cover it all: Stable income (Employment Contract or B2B) Participation in the Employee Stock Purchase Plan Benefits package (health insurance, multisport, shopping vouchers) Strategically located offices featuring entertainment and relaxation zones, table tennis and football, free snacks, fantastic coffee, and more Referral bonuses Corporate, social and well-being events Please, note: The set of bonuses might vary based on the role you apply for – specifics will be discussed with our recruiter during the general interview. We will reach out to selected candidates exclusively. EPAM is a leading global provider of digital platform engineering and development services. We are committed to having a positive impact on our customers, our employees, and our communities. We embrace a dynamic and inclusive culture. Here you will collaborate with multi-national teams, contribute to a myriad of innovative projects that deliver the most creative and cutting-edge solutions, and have an opportunity to continuously learn and grow. No matter where you are located, you will join a dedicated, creative, and diverse community that will help you discover your fullest potential.

🏢 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