Senior Full Stack Engineer (.NET / React)

🏢 Summary: Hybrid Fullstack Engineer role in Warsaw focused on building scalable enterprise applications using Node.js, C#, .NET, React, AngularJS, and SQL Server. The position involves backend and frontend development, architecture contributions, and collaboration with cross-functional engineering teams. Experience with cloud-native and containerized technologies is considered a plus. 🗂️ Requirements: 7+ years of full-stack development experience, Expertise in React, Expertise in Node.js, Expertise in C#, Expertise in ASP.NET, Strong SQL Server experience, Experience building scalable enterprise applications, Experience developing APIs, Strong application design skills, Analytical and problem-solving skills, Attention to software quality, Communication skills, Collaboration skills 📃 Skills: Node.js, C#, .NET, React, AngularJS, SQL, T-SQL, ASP.NET, SQLServer, APIs, Cloud, Containers, Streaming 🏢 Description: Fullstack Engineer Warsaw, hybrid. Responsibilities Develop and maintain server-side applications using Node.js, C#, and .NET . Build responsive user interfaces with React and AngularJS . Design and optimize SQL Server solutions, including T-SQL and stored procedures. Contribute to application architecture, technical design, and technology decisions. Build scalable solutions leveraging modern cloud, container, and streaming technologies. Collaborate with cross-functional engineering teams to deliver high-quality software. Requirements 7+ years of full-stack development experience . Strong hands-on expertise in React, Node.js, C#, ASP.NET , and SQL Server . Experience developing scalable enterprise applications and APIs. Strong application design, analytical, and problem-solving skills. High attention to detail and commitment to software quality. Excellent communication and collaboration skills. Nice to Have Experience with cloud-native, containerized, or event-driven architectures. Financial services or large enterprise environment experience.

🏢 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: Senior Full Stack Developer role focused on building enterprise-grade applications for capital markets and risk using React and C# .NET Core. The position involves developing scalable microservices, REST APIs, modern web UIs, and data-driven solutions in a cloud environment. Responsibilities include CI/CD implementation, event-driven architecture, cloud migration, and Power BI reporting. 🗂️ Requirements: Strong experience with React and TypeScript, Strong experience with C# and .NET Core, Experience building REST APIs, Experience developing microservices and distributed systems, Experience with CI/CD pipelines, Experience with Azure or AWS cloud platforms, Experience with Power BI and data modeling, Strong SQL and database knowledge, Experience with Docker and Kubernetes, Experience in capital markets domain especially credit risk or market risk, Strong understanding of software architecture and system design 📃 Skills: React, TypeScript, JavaScript, C#, DotNetCore, REST, Microservices, Azure, AWS, PowerBI, SQL, Docker, Kubernetes, Kafka, AzureDevOps, Jenkins, GitHubActions 🏢 Description: About the Role We are looking for a Senior Full Stack Developer with strong expertise in React on the frontend and C# .NET Core on the backend to build and enhance enterprise-grade applications in the capital markets and risk domain. The role involves developing scalable microservices, modern web applications, and data-driven solutions in a cloud environment. Key Responsibilities Design, develop, and maintain full stack applications using React and C# .NET Core Build and maintain REST APIs and microservices in distributed environments Develop modern, responsive UI components using React, TypeScript, and modern frontend patterns Work closely with business stakeholders in capital markets and risk domains (credit risk, market risk) Develop and maintain Power BI dashboards and data models for business reporting Implement and maintain CI/CD pipelines and automated deployment processes Contribute to event-driven architecture using tools such as Kafka or similar messaging technologies Participate in cloud migration and modernization initiatives (Azure or AWS) Ensure code quality through testing, code reviews, and best engineering practices Mentor junior developers and contribute to architectural decisions Requirements Strong experience with React, JavaScript/TypeScript Strong experience with C#, .NET Core, REST APIs Experience building microservices and distributed systems Experience with CI/CD tools (Azure DevOps, Jenkins, GitHub Actions) Experience with Azure or AWS Experience with Power BI and data modeling Strong SQL and database knowledge Experience with Docker / Kubernetes Experience working in capital markets , especially credit risk or market risk Strong understanding of software architecture and system design Excellent communication skills and experience working with business stakeholders

🏢 Summary: Senior Fullstack Engineer role focused on building scalable enterprise applications using .NET and React in a hybrid Krakow-based environment. The position involves full software lifecycle ownership, UI improvements, DevOps automation, architecture contributions, and customer-facing solution delivery. 🗂️ Requirements: 7+ years of experience in .NET application development, Experience with React frontend development, Proficiency in C#, Experience with Web API development, Advanced SQL Server and T-SQL skills, Understanding of SDLC processes, Experience with DevOps practices, Fluent English, Legal right to work in the European Union 📃 Skills: .NET, React, C#, WebAPI, SQL, SQLServer, TSQL, 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 Fullstack Engineer role focused on developing scalable enterprise applications using .NET and React in a hybrid Krakow-based environment. The position involves full lifecycle development, UI enhancements, DevOps automation, architecture contributions, and customer-focused solution delivery. 🗂️ Requirements: 7+ years of experience in .NET application development, Experience with React frontend development, Proficiency in C#, Experience with Web API development, Advanced SQL Server and T-SQL skills, Understanding of SDLC processes, Experience with DevOps practices, Fluent English, Legal right to work in the European Union 📃 Skills: .NET, React, C#, WebAPI, 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 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 .NET Fullstack Developer role focused on building scalable applications with React front-end and .NET backend while driving DevOps transformation and CI/CD optimization. The position combines full-stack development, architecture design, and automation within a data-driven DevOps environment. Hybrid work model with strong emphasis on engineering excellence and lifecycle management. 🗂️ Requirements: Minimum 7 years of experience in .NET production development, Strong proficiency in C# and Web API, Hands-on experience with React, Experience with SQL Server and T-SQL, Experience in CI/CD and DevOps automation, Knowledge of SDLC, Fluent English, Legal right to work in the EU 📃 Skills: .NET, C#, WebAPI, React, SQLServer, T-SQL, CI/CD, DevOps, Azure, Cloud, Docker, Kubernetes 🏢 Description: Unleash innovative solutions — shape the future of DevOps and full-stack excellence! Krakow-based opportunity with hybrid work model (up to 3 remote days per week). As a Senior .NET Fullstack Developer — React & DevOps Expertise , you will be working for our client, a leader in banking innovation, providing critical analytics and metrics that empower strategic transformation across engineering teams worldwide. Join a trailblazing team driving DevOps transformation through cutting-edge data, analytics, and practices—be a key driver of impactful change and technological evolution. Your main responsibilities: Implement solutions following best design patterns to ensure scalable and maintainable applications. Analyze requirements thoroughly and recommend improvements for optimal performance. Lead UI enhancements to elevate user experience and application stability. Actively participate in DevOps automation and optimize the CI/CD lifecycle. Contribute to software architecture design and develop application prototypes to validate concepts. Provide exceptional customer support by promptly addressing and resolving issues. Collaborate effectively with stakeholders to understand needs and deliver tailored solutions. You're ideal for this role if you have: Minimum of 7 years of professional experience in production application development within the .NET ecosystem, including React front-end development. Strong proficiency in C# and Web API development, with a focus on scalable and secure backend services. Hands-on experience with React, creating dynamic, interactive web applications. Expertise in database design, SQL Server, T-SQL scripting, and query optimization. Experience in DevOps activities like CI/CD, automation, and lifecycle management. Familiarity with the full Software Development Life Cycle (SDLC). Excellent problem-solving skills with high attention to detail under pressure. It is a strong plus if you have: Certifications in Azure, DevOps, or related fields. Experience with cloud platforms and containerization tools. Language Required for the role: Fluent English 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 .NET Developer role focused on modernizing a legacy business process management platform within a digital banking environment. The position involves rebuilding applications from .NET Framework to modern .NET, developing React frontend components, and deploying scalable solutions to Kubernetes. You will contribute to system design, automated testing, and AI-assisted development in an enterprise Agile setup. 🗂️ Requirements: 5+ years of experience with C# and .NET, Experience modernizing legacy applications from .NET Framework, Strong knowledge of React, Practical experience with LLM tools (Claude, Codex), Experience with automated testing, Hands-on experience with Docker and Kubernetes, Experience designing and implementing enterprise applications, Strong knowledge of MS SQL, Experience with Git, JIRA, and TeamCity 📃 Skills: CSharp, DotNet, DotNetFramework, React, Kubernetes, Docker, MSSQL, Git, JIRA, TeamCity, Claude, Codex, Agile 🏢 Description: Unleash innovative web solutions — shape the future of digital banking experiences! Łódź-based opportunity with hybrid work model (2 days in the office/month). As a Senior Fullstack .NET React Developer , you will be working for our client, a leading financial institution focused on delivering innovative digital banking solutions. You will join a strategic modernization initiative involving the redevelopment of a business process management platform. The project focuses on rebuilding legacy applications from .NET Framework to modern .NET technologies, migrating infrastructure from on-premises environments to Kubernetes, and implementing high-quality engineering practices. You will collaborate closely with AI-powered development tools, contribute to system design decisions, and help deliver scalable, secure, and maintainable solutions in a complex enterprise environment. Your main responsibilities: Develop and maintain backend services using .NET and C# Rebuild legacy applications from .NET Framework to modern .NET architecture Design and implement frontend components using React Create and maintain automated unit and regression tests Collaborate with business stakeholders to analyze and refine requirements Design scalable and maintainable software solutions Integrate applications with databases and external services Utilize LLM-based tools such as Claude and Codex to support software development activities Participate in code reviews and ensure adherence to development standards Deploy and support applications running in Kubernetes environments Work closely with cross-functional teams in an Agile delivery model You're ideal for this role if you have: At least 5 years of experience in software development using C# and .NET Experience with .NET Framework and modernizing legacy code Good knowledge of React Practical experience working with LLM tools such as Claude and Codex Strong experience with automated testing Hands on experience with Docker and Kubernetes Experience designing and implementing enterprise applications Strong knowledge of MS SQL Experience using Git, JIRA, and TeamCity Ability to work independently while collaborating effectively within a team English skills sufficient to write and understand technical documentation Nice to have: Knowledge of message brokers, especially RabbitMQ,