Full-stack Developer (React, C#)

🏢 Summary: Full Stack Developer role focused on building scalable, cloud-native applications using React and C# .NET Core in a capital markets environment. The position involves developing microservices, REST APIs, data pipelines, and analytical solutions supporting credit and market risk domains. 100% remote B2B contract with flexible start date. 🗂️ Requirements: 4-5+ years of full stack development experience, Strong expertise in React, Strong expertise in C#, Experience with .NET Core, Experience with microservices architecture, Experience with event-driven architecture, Experience with distributed systems, Experience building REST APIs, Hands-on experience with Python, Experience with PySpark, Experience with Power BI, Experience with data modeling, Experience in credit risk and market risk domains 📃 Skills: React, C#, .NETCore, Microservices, REST, TypeScript, Python, PySpark, PowerBI, DataModeling, DistributedSystems, EventDriven, Cloud 🏢 Description: Start Date: ASAP / Within 1 Month / Flexible Work Model: 100% remote Contract Type: B2B (140-160 PLN/h + VAT) We are looking for a highly skilled Full Stack Developer with deep expertise in React for frontend development and C# .NET Core for backend services. This role requires hands‑on experience building scalable, cloud‑native systems, along with strong exposure to capital markets, especially within credit risk and market risk domains. Expectations Minimum 4-5 years of professional software development experience across frontend and backend technologies. Strong expertise in React, C# .NET Core , microservices, event‑driven architecture, and distributed systems. Hands‑on experience with Python (pyspark), Power BI dashboards, data modeling, and analytical reporting. Responsibilities Develop and maintain full stack applications using React, C# .NET Core, and modern cloud‑native technologies. Build scalable backend services, REST APIs, and microservices with a focus on performance and resilience. Implement modular, accessible, and high‑quality frontend components using React and TypeScript. Collaborate with business and risk experts to deliver solutions in credit risk, market risk, and capital markets workflows. Work with Python (pyspark) to build data pipelines, transformations, and analytics processes. What We Offer Medicover healthcare package Multisport card Access to an e-learning platform Group life insurance

🏢 Summary: Fullstack Developer role focused on building and developing business software and SaaS solutions using .NET and React within a Scrum team. The position involves working with microservices architecture, Microsoft Azure, and maintaining development and production environments. The candidate will contribute to product development, system monitoring, and technical documentation. 🗂️ Requirements: Minimum 2 years commercial experience with C# and .NET, Good knowledge of .NET Core, Good knowledge of React JS, Good knowledge of TypeScript, Very good knowledge of SQL, Experience with microservices architecture, Experience working in a Scrum team, Ability to create technical documentation 📃 Skills: C#, .NET, .NETCore, React, TypeScript, SQL, Azure, Docker, Kubernetes, Scrum, Microservices 🏢 Description: Jako firma rekrutacyjna jesteśmy świadomi, że każdy solidny biznes napędzają ludzie z odpowiednio dopasowanymi kompetencjami. Nasz styl zarządzania i partnerskie podejście pozwalają nam na elastyczne dostosowanie się do Twoich potrzeb i zapewniają pełne wsparcie podczas współpracy. W związku z ciągłym rozwojem i dużą liczbą projektów rekrutacyjnych, jakie prowadzimy dla naszych Partnerów, szukamy osoby na stanowisko: Fullstack Developer (.NET + React) Zakres obowiązków: Rozwój oprogramowania dla klientów biznesowych Współudział w tworzeniu nowych produktów i rozwiązań SaaS Praca w zespole scrumowym i udział w ceremoniach projektowych Implementacja rozwiązań w technologiach C#, .NET, .NET Core, React JS i TypeScript Tworzenie i utrzymywanie aplikacji opartych o Microsoft Azure i architekturę mikroserwisową Definiowanie wymagań we współpracy z Product Ownerem i klientem Konfiguracja i utrzymanie środowisk developerskich oraz produkcyjnych Monitorowanie i rozwiązywanie błędów w systemach Wymagania: Minimum 2 lata doświadczenia komercyjnego w pracy z C# i .NET Dobra znajomość .NET Core oraz React JS / TypeScript Bardzo dobra znajomość SQL Doświadczenie w pracy z architekturą mikroserwisową Umiejętność pracy w zespole scrumowym Umiejętność przygotowywania dokumentacji technicznej Systematyczność i samodzielność Mile widziane: Znajomość Docker lub Kubernetes Doświadczenie w projektach z branży ubezpieczeniowej Znajomość środowiska Microsoft Azure Oferujemy: Prywatną opiekę medyczną Dofinansowanie karty sportowej Dofinansowanie do szkoleń i programy rozwojowe Dodatkowy pakiet benefitów

🏢 Summary: Hybrid Fullstack Developer role focused on building and maintaining scalable web applications using Java and React.js. The position involves designing backend services and RESTful APIs, developing modern frontend interfaces, and contributing to CI/CD and DevOps practices. Work includes testing, performance optimization, and collaboration on architecture and microservices. 🗂️ Requirements: Strong experience with Java and Spring Boot, Solid experience with React.js and state management, Experience designing and consuming RESTful APIs, Experience with microservices architecture, Proficiency in JavaScript, HTML5, CSS3, Experience with relational or NoSQL databases, Knowledge of unit and integration testing practices, Experience with CI/CD pipelines, Familiarity with Git and version control workflows, Ability to work with Agile/Scrum methodologies 📃 Skills: Java, Spring, SpringBoot, React, Redux, JavaScript, HTML5, CSS3, Webpack, Babel, ESLint, JUnit, Mockito, Jest, MySQL, PostgreSQL, NoSQL, Git, CI/CD, Docker, Kubernetes, AWS, Azure, GCP, Kafka, GraphQL, WebSocket 🏢 Description: We are looking for a highly skilled Fullstack Developer with expertise in Java and React.js to join our Kraków-based development team. You will design, develop, and maintain scalable, high-performance web applications, contributing to both backend services and rich frontend interfaces. This role follows a hybrid working model , with 2–3 days per week onsite in Kraków. Key Responsibilities Backend Development: Architect, implement, and maintain backend services using Java , Spring Boot , and related frameworks Frontend Development: Build responsive, modular, and maintainable React.js applications with a focus on component-driven design Design and implement RESTful APIs and microservices , ensuring high performance, security, and scalability Collaborate with cross-functional teams to define technical requirements , system architecture, and feature implementation Apply unit testing, integration testing, and end-to-end testing best practices (JUnit, Mockito, Jest, React Testing Library) Participate in code reviews , enforce coding standards, and promote best practices in clean code, SOLID principles, and design patterns Troubleshoot and optimize application performance and resolve production issues Manage CI/CD pipelines , automate deployments, and support DevOps practices Stay up-to-date with emerging technologies and frameworks to continuously improve application architecture Required Skills and Experience Strong experience with Java , Spring Boot , and related backend frameworks Solid experience with React.js , Redux , or state management libraries Proven experience in designing and consuming RESTful APIs and microservices architecture Proficient in JavaScript, HTML5, CSS3, and modern frontend tooling (Webpack, Babel, ESLint) Experience with relational databases (MySQL, PostgreSQL) and/or NoSQL databases Familiarity with Git , version control workflows, and Agile/Scrum methodologies Understanding of unit testing, integration testing, and test-driven development (TDD) Good problem-solving and communication skills in English Nice to Have Experience with TypeScript and advanced React patterns (Hooks, Context API, Suspense) Knowledge of Docker , Kubernetes , or cloud platforms (AWS, Azure, GCP) Experience with event-driven architectures , message queues , or Kafka Familiarity with GraphQL or WebSocket-based real-time applications

🏢 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,

🏢 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: B2B contract for a Mid Fullstack Developer to build and enhance a fintech document management portal using .NET and React. You will join a small team and contribute directly to product development and technical decisions in a 3–4 month project with possible extension. 🗂️ Requirements: Minimum 3 years of commercial experience, Strong knowledge of .NET, Strong knowledge of C#, Experience with React, Experience with TypeScript, Knowledge of SQL databases, Knowledge of NoSQL databases, English level B2 or higher 📃 Skills: .NET, C#, React, TypeScript, SQL, NoSQL, Azure, AWS, GCP 🏢 Description: 🚀 Mid Fullstack Developer (.NET + React) 💼 B2B | 100–140 PLN netto/h 📍 Hybryda / Biuro ⏳ Projekt na 3–4 miesiące z możliwością przedłużenia 🚀 Start: ASAP 🔎 O projekcie Poszukujemy Mid Fullstack Developera do projektu realizowanego dla klienta z branży fintech . Startup rozwija nowoczesny portal do zarządzania dokumentami finansowymi oraz procesami związanymi z obiegiem dokumentacji. Dołączysz do niewielkiego, 3-osobowego zespołu , gdzie będziesz mieć realny wpływ na rozwój produktu oraz decyzje techniczne. 🛠️ Tech Stack .NET / C# React TypeScript SQL / NoSQL Cloud (mile widziane) ✅ Wymagania min. 3 lata doświadczenia komercyjnego bardzo dobra znajomość .NET oraz C# doświadczenie z React i TypeScript znajomość baz danych SQL / NoSQL komunikatywny język angielski ( min. B2 ) umiejętność pracy w małym, dynamicznym zespole ⭐ Mile widziane doświadczenie z rozwiązaniami chmurowymi ( Azure / AWS / GCP ) doświadczenie w projektach fintech lub SaaS 🎁 Oferujemy 💰 Stawka: 100–140 PLN netto/h (B2B) 🏢 Możliwość pracy hybrydowej lub z biura 🚀 Szybki proces rekrutacyjny 🧩 Realny wpływ na rozwój produktu i decyzje techniczne ⚡ Start projektu ASAP 📩 Jeśli chcesz dołączyć do dynamicznego fintech startupu i pracować przy rozwoju nowoczesnego produktu — aplikuj!

🏢 Summary: Senior Full Stack Developer role focused on designing, building, and enhancing enterprise-level applications using .NET and React. The position involves contributing to architecture decisions, improving performance and usability, and ensuring application reliability across the full technology stack. It includes ownership of backend services, frontend development, CI/CD processes, and production support. 🗂️ Requirements: Minimum 5 years of professional experience in .NET application development, Strong proficiency in C# and Web API, Hands-on experience with React for web application development, Advanced knowledge of SQL Server and database architecture, Experience with CI/CD pipelines, Understanding of Software Development Life Cycle, Proficiency in HTML5 and CSS, Experience in system architecture and design patterns, Ability to troubleshoot production issues 📃 Skills: .NET, C#, WebAPI, React, SQL, SQLServer, CI/CD, HTML5, CSS, SDLC 🏢 Description: We Are Hiring: Senior Full Stack Developer (.NET and React) We are seeking an experienced Full Stack Developer who is ready to play a key role in designing, building, and improving enterprise-level applications. This position is ideal for someone who enjoys working across the entire technology stack, contributing to architectural decisions, enhancing user experiences, and ensuring application reliability and performance. This is a senior-level opportunity for a professional who combines deep technical expertise with strong analytical thinking and a proactive mindset. Key Responsibilities Contribute to system architecture planning and technical design discussions Drive user interface enhancements to improve usability, performance, and overall application resilience Apply industry-recognized design principles and architectural patterns when implementing solutions Review and interpret business and technical requirements, proposing improvements where appropriate Produce clear and detailed technical documentation for developed features and systems Build proof-of-concept solutions and prototypes to validate architectural approaches Oversee and manage system modifications within structured service management processes Support and enhance automation initiatives across development and operational workflows Deliver high-quality technical support, ensuring timely resolution of issues Collaborate closely with stakeholders to understand objectives and provide effective solutions Required Qualifications and Experience A minimum of Five years of professional experience developing and maintaining production-grade applications within the .NET ecosystem Strong proficiency in C# and Web API development, with experience building secure, scalable, and high-performing backend services Solid hands-on experience with React, developing dynamic, responsive, and performance-optimized web applications Advanced knowledge of database architecture and SQL Server, including complex query development, performance optimization, and tuning Practical experience with continuous integration and continuous delivery pipelines Comprehensive understanding of the Software Development Life Cycle, from requirements analysis through deployment and ongoing support Strong command of modern web standards including HTML5 and Cascading Style Sheets, with the ability to create intuitive user interfaces Excellent analytical and troubleshooting abilities, particularly in demanding production environments High attention to detail and commitment to delivering robust, maintainable solutions If you are passionate about developing high-quality software, improving system performance, and contributing to meaningful technical decisions, we would welcome the opportunity to connect with you. Please feel free to reach out directly or share this opportunity within your professional network. #Hiring #FullStackDeveloper #DotNet #React #SoftwareEngineering #TechnologyCareers

🏢 Summary: Full-Stack Developer role focused on building and enhancing business applications using C#/.NET on the backend and React (18+) on the frontend. The position involves developing new features, maintaining and improving legacy code, and contributing to solution design within an Agile/Scrum team. Strong emphasis on backend expertise, frontend development, and architectural best practices. 🗂️ Requirements: 5+ years of experience with .NET and C#, 3+ years of experience with React (18+), Strong knowledge of .NET Framework, .NET Standard, .NET Core/.NET, Experience with debugging, profiling and performance analysis, Understanding of DDD, Clean Code and SOLID principles, Knowledge of architectural patterns and asynchronous communication, Good command of T-SQL, Experience with SQL Server Management Studio (SSMS), Experience with Visual Studio 📃 Skills: C#, .NET, React, TSQL, SQLServer, SSMS, VisualStudio, DDD, SOLID, CleanCode, Scrum, Debugging, Profiling, Architecture, Asynchronous 🏢 Description: We’re looking for an experienced Full-Stack Developer to build and evolve business applications using C#/.NET on the backend and React on the frontend. You’ll work closely with a cross-functional team (QA, Analysts, Product Owner) in an Agile/Scrum environment, contributing to both new development and improvements to existing (including legacy) codebases. Key responsibilities: Develop software in C# based on functional and technical documentation Build and maintain the frontend using React (18+) Analyse and improve existing code, including legacy components Contribute to solution design and architecture Collaborate daily with developers, testers, analysts and the Product Owner in Scrum Requirements: 5+ years of experience building applications with .NET / C# 3+ years of experience building applications with React Strong knowledge of C# (.NET Framework, .NET Standard, .NET Core/.NET) React experience with modern versions (React 18+) Practical skills in debugging, profiling and performance analysis Understanding of DDD, Clean Code, SOLID Knowledge of architectural patterns and asynchronous communication Good command of T-SQL and SQL Server Management Studio (SSMS) Experience working with Visual Studio Nice to have Experience building views/UI for mobile applications Background in projects for the financial sector Test automation experience (e.g., Postman, Playwright) Familiarity with WCAG accessibility standards

🏢 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 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