Fullstack Developer with C#.NET & React - Krakow- Hybrid

🏢 Summary: Senior .NET Full Stack Developer role focused on building and supporting enterprise web applications, RESTful APIs, and frontend and backend solutions. The position combines hands-on development with technical decision-making, testing, CI/CD, releases, production support, and hybrid work from Lisbon. 🗂️ Requirements: Degree in Computer Science, Software Engineering, Information Technology, Engineering, or related technical field, 5–8 years of relevant .NET full-stack development experience, Strong .NET Core, .NET Framework, and MVC expertise, Experience with React, Angular, JavaScript, and legacy technologies, Strong SQL and Entity Framework knowledge, Production application support experience, CI/CD, Azure DevOps, Jenkins, and Git experience, Authentication and core security principles knowledge, Unit and integration testing experience, Professional English proficiency, minimum B2 📃 Skills: .NET, MVC, React, Angular, JavaScript, C#, SQL, EntityFramework, REST, AzureDevOps, Jenkins, Git, CI/CD, Authentication 🏢 Description: We are seeking a highly skilled Senior .Net Full Stack Developer with expertise in .NET Framework and extensive experience in developing full-stack web applications. The role requires a proactive individual who is capable of making critical technical decisions and contributing effectively within a collaborative team environment. Key Responsibilities Design, develop, maintain, and enhance full-stack web applications. Build and integrate RESTful APIs across enterprise platforms. Gather, analyze, and refine business and technical requirements. Contribute to technical decisions and help prioritize development activities. Develop frontend solutions using React, Angular, JavaScript , and legacy technologies. Develop backend solutions using .NET Core, .NET Framework, and C#. Work with SQL Server and related data access technologies. Perform unit testing and integration testing to ensure quality and reliability. Participate in release and deployment management activities. Support and improve CI/CD pipelines and DevOps practices . Troubleshoot and resolve production incidents , including high-priority issues. Manage and contribute to risk, issue, incident, and problem resolution . Ensure adherence to coding standards, development guidelines, naming conventions, templates, and reference implementations. Produce and maintain clear technical documentation. Collaborate effectively within the team and across distributed, cross-functional, and international teams. Required Qualifications Degree in Computer Science, Software Engineering, Information Technology, Engineering , or a related technical field. 5 to 8 years of relevant professional experience as a .Net Full Stack Developer . Strong expertise in .NET Core/Framework/MVC and related frameworks. Solid experience with React, Angular, JavaScript and working with older or legacy technologies when required. Strong knowledge of SQL and ORM tools such as Entity Framework . Experience working in production environments and supporting live business applications. Hands-on experience with CI/CD, Azure DevOps, Jenkins, and Git . Understanding of authentication mechanisms and core security principles . Experience in development, unit testing , and integration testing . Nice to Have Strong team player who collaborates effectively within and across teams. Proactive mindset with strong ownership and accountability. Good knowledge of Agile ways of working . Experience in documentation and standards ownership . Structured approach to release management, incident management, and problem-solving . Ability to work effectively in a dynamic, fast-paced environment. Experience with requirement gathering, analysis , and solution design . Strong skills in decision-making, prioritization , and communication . Language Requirements Professional proficiency in English speaking and writing (at least B2 level). Dutch and/or French is a strong plus. Work model: 2 days per week in the Lisbon office and 3 days at home.

🏢 Summary: Oferta dotyczy realizacji projektów jako Senior Fullstack Developer, obejmujących rozwój, utrzymanie i projektowanie architektury aplikacji webowej w .NET i React. Praca jest głównie zdalna, z okresowymi spotkaniami koordynacyjnymi w Gdańsku lub Warszawie, w modelu B2B rozliczanym etapowo. 🗂️ Requirements: Minimum 5 lat doświadczenia w .NET, Minimum 3 lata doświadczenia w React, Bardzo dobra znajomość C# i platformy .NET, Znajomość React 18+, Znajomość DDD, Clean Code i SOLID, Znajomość wzorców architektonicznych i komunikacji asynchronicznej, Znajomość T-SQL i SQL Server Management Studio, Znajomość Visual Studio, Język angielski minimum B2, Biegła znajomość języka polskiego, Gotowość do spotkań w Gdańsku lub Warszawie około raz w tygodniu 📃 Skills: C#, .NET, React, T-SQL, SQLServer, SSMS, VisualStudio, DDD, SOLID, Scrum 🏢 Description: Wspólnie z naszym Partnerem Biznesowym poszukujemy doświadczonego specjalisty do realizacji projektów jako Senior Fullstack Developer (.NET + React). Projekt zakłada rozwój i utrzymanie aplikacji webowej opartej o technologie .NET oraz React, w tym pracę z istniejącym kodem oraz współtworzenie architektury nowych rozwiązań. 💡 ZAKRES USŁUG - Projektowanie i wytwarzanie oprogramowania w języku C# zgodnie z dostarczoną dokumentacją. - Implementacja warstwy frontendowej aplikacji w technologii React (18+). - Analiza oraz rozwój istniejącego kodu, w tym komponentów legacy. - Opracowywanie architektury rozwiązań technologicznych. - Debugowanie, profilowanie oraz analiza wydajności realizowanych rozwiązań. - Bieżąca współpraca z interesariuszami projektu (testerami, analitykami, Product Ownerem) w ramach zwinnego podejścia do realizacji usług (Scrum). 🔍 WYMAGANE KOMPETENCJE - Min. 5 lat doświadczenia w wytwarzaniu aplikacji w technologii .NET. - Min. 3 lata doświadczenia w wytwarzaniu aplikacji w React. - Bardzo dobra znajomość języka C# (.NET Framework, .NET Standard, .NET Core, .NET). - Znajomość React w wersji 18 i nowszych. - Znajomość zasad DDD, Clean Code oraz SOLID. - Znajomość wzorców architektonicznych oraz komunikacji asynchronicznej. - Znajomość TSQL oraz SQL Server Management Studio. - Znajomość środowiska Visual Studio. - Znajomość języka angielskiego w mowie i piśmie na poziomie min. B2 oraz biegła znajomość języka polskiego. - Zdolność analitycznego myślenia i swoboda w pracy z dokumentacją techniczną. - Samodzielna organizacja pracy oraz dbałość o jakość i terminowość realizowanych usług. Mile widziane: - Doświadczenie w budowaniu widoków dla aplikacji mobilnych. - Doświadczenie w budowaniu aplikacji dla sektora finansowego. - Doświadczenie w automatyzacji testów (np. Postman, Playwright). - Znajomość standardu WCAG. - Wykształcenie wyższe kierunkowe (informatyczne). TRYB WSPÓŁPRACY Gotowość do spotkań koordynacyjnych w Gdańsku lub Warszawie (orientacyjnie 1x w tygodniu, z możliwością zwiększenia częstotliwości w przyszłości). Pozostały zakres usług realizowany zdalnie. ✨ OFERUJEMY - Nowy sposób na aplikowanie z AI Rekruterem (AIR) – w trakcie procesu możesz porozmawiać z wirtualnym rekruterem 24/7, bez czekania na telefon. Finalną decyzję zawsze podejmuje Opiekun Projektu. - Współpracę w modelu projektowym, z rozliczeniem opartym na etapach i protokołach odbioru poszczególnych deliverables. - Wsparcie po stronie Connectis w sprawach administracyjnych i rozliczeniowych związanych ze współpracą. - Uczestnictwo w wydarzeniach branżowych oraz meetupach technologicznych. - 5 000 PLN za polecenie znajomych do naszych projektów. - Elastyczną formę współpracy B2B. - Szybki i zdalny proces. Dziękujemy za wszystkie zgłoszenia. Pragniemy poinformować, że skontaktujemy się z wybranymi osobami.

🏢 Summary: Senior Full Stack Engineer role focused on leading the delivery of scalable, business-critical web applications. The position combines React/Remix front-end development with Python REST APIs, Azure cloud deployment, automated testing, and DevSecOps practices while providing technical leadership in an Agile team. 🗂️ Requirements: Senior full-stack engineering experience, TypeScript, React, Python, RESTful API development, MongoDB, SQL databases, Microsoft Azure, Azure Kubernetes Service, Clean, testable code, Test-driven development, Vitest, Pytest, DevSecOps practices, GitHub workflows, GitHub Actions CI/CD, Kubernetes, ArgoCD, Problem-solving, Technical communication, Bachelor’s degree or equivalent professional experience 📃 Skills: TypeScript, React, Remix, Python, MongoDB, SQL, Azure, AKS, Vitest, Pytest, GitHub, GitHubActions, Kubernetes, ArgoCD, DevSecOps, TDD, GitOps, ES6 🏢 Description: We are seeking an experienced Senior Full Stack Engineer to join a high-performing engineering team responsible for building and enhancing innovative web-based platforms. This role offers the opportunity to work on complex, business-critical applications while driving technical excellence, engineering best practices, and scalable software solutions. As a Senior Engineer, you will take ownership of advanced development initiatives, contribute to architectural decisions, and help shape the future direction of modern web applications. You will work across both front-end and back-end technologies , combining expertise in React-based user interfaces and Python API development to deliver secure, scalable, and maintainable solutions. The ideal candidate will have strong full-stack engineering experience, a passion for clean code and automation, and the ability to solve complex technical challenges within a collaborative, agile environment. Key Responsibilities Lead the design, development, and delivery of complex software engineering initiatives from concept through to production. Architect and build scalable Python RESTful APIs and modern React/Remix-based web applications using service-oriented architecture principles. Develop reusable components, integrations, and technical solutions that improve application scalability and maintainability. Investigate, troubleshoot, and resolve complex technical issues, providing effective solutions and long-term improvements. Establish and promote engineering best practices across development, testing, security, and deployment processes. Champion a DevOps-first mindset , supporting automation, continuous delivery, and operational excellence. Define and address non-functional requirements including performance, accessibility, reliability, and security. Collaborate closely with Product Owners, architects, engineers, and business stakeholders to translate requirements into innovative technical solutions. Provide technical guidance and mentorship to other engineers, encouraging knowledge sharing and continuous improvement. Contribute to Agile delivery practices, supporting effective planning, estimation, and iterative development. Essential Skills & Experience Proven experience as a Senior Full Stack Engineer or similar technical leadership role, delivering complex software solutions. Strong proficiency in TypeScript , including modern ES6+ features and best practices. Extensive experience building dynamic, responsive front-end applications using React , with experience in Remix or similar frameworks preferred. Strong backend development experience using Python , including the design and implementation of RESTful APIs. Solid understanding of database technologies, including MongoDB and relational SQL databases. Hands-on experience with Microsoft Azure , particularly Azure Kubernetes Service (AKS) and cloud-native application deployment. Strong commitment to writing clean, maintainable, and highly testable code. Experience with Test Driven Development (TDD) and automated testing frameworks, including: Unit testing with Vitest and Pytest Functional testing exposure with Playwright is desirable. Strong understanding of modern DevSecOps practices , including: GitHub version control workflows CI/CD automation using GitHub Actions Containerised application deployment using Kubernetes GitOps practices with ArgoCD Excellent problem-solving skills with strong attention to technical detail and quality. Strong communication skills with the ability to collaborate effectively with both technical and non-technical stakeholders. Bachelor’s degree in Computer Science, Engineering, or a related discipline, or equivalent professional experience. Desirable Skills Azure Developer certification, particularly AZ-204 . Experience working with Databricks or modern data platforms. Experience working in Scrum-based Agile environments . Previous experience working with large-scale enterprise applications and distributed systems.

🏢 Summary: Oferta B2B dla Full Stack Developera .NET/React obejmuje zdalną pracę przy rozwoju, utrzymaniu i wsparciu aplikacji enterprise w międzynarodowym projekcie. Rola łączy tworzenie backendu, frontendu, API i mikroserwisów z obsługą aplikacji L2/L3/L4, monitoringiem oraz dyżurami on-call 24/7. Wynagrodzenie wynosi do 140 PLN netto + VAT za godzinę. 🗂️ Requirements: C#, NET Framework, NET Core, NET 6+, ASP.NET MVC, ASP.NET Web API, REST API, Microservices, React, JavaScript ES6+, TypeScript, HTML5, CSS3, Material UI, Microsoft Azure, Azure DevOps, CI/CD, Azure SQL, Cosmos DB, Docker, Monitoring, Observability, Troubleshooting, Application Support, Git, GitHub, Azure Repos, Gotowość do rotacyjnych dyżurów on-call 24/7 📃 Skills: C#, .NET, ASP.NET, REST, Microservices, React, JavaScript, TypeScript, HTML5, CSS3, Azure, DevOps, SQL, Cosmos, Docker, Monitoring, Observability, Troubleshooting, Git, GitHub 🏢 Description: Poszukujemy Full Stack Developer (.NET / React) , który docelowo będzie realizował projekt dla jednego z naszych klientów — jedna z największych międzynarodowych firm doradczych , która realizuje projekty technologiczne i biznesowe dla globalnych organizacji. Zespół IT klienta rozwija i utrzymuje nowoczesne aplikacje oraz rozwiązania chmurowe wykorzystywane w środowiskach enterprise. To oferta dla osoby, która dobrze odnajduje się zarówno w rozwoju aplikacji, jak i w obszarze L2/L3/L4 Application Support , a jednocześnie chce pracować z nowoczesnym stackiem technologicznym. Oferujemy 100% pracę zdalną , współpracę na podstawie B2B , wynagrodzenie do 140 PLN netto + VAT/h , pracę przy międzynarodowym projekcie dla dużej organizacji, nowoczesny stack technologiczny oparty o .NET, React i Azure. Obowiązki rozwój nowych aplikacji oraz rozbudowa już istniejących systemów, tworzenie nowych funkcjonalności od strony backendu i frontendu, rozwój oraz utrzymanie REST API i mikroserwisów, analiza i usuwanie błędów pojawiających się na produkcji, obsługa zgłoszeń, incydentów i problemów związanych z działaniem aplikacji, diagnozowanie problemów oraz szukanie ich przyczyn, współpraca z zespołami developerskimi, QA, infrastrukturą oraz biznesem, monitorowanie aplikacji i reagowanie na problemy w środowisku produkcyjnym, udział w działaniach związanych z poprawą stabilności, wydajności i jakości systemów, tworzenie i utrzymywanie testów oraz automatyzacji, praca z pipeline'ami CI/CD i procesem wdrażania aplikacji. 24/7 Support — ważna informacja Rola obejmuje również wsparcie aplikacji w modelu 24/7 . Oznacza to udział w rotacyjnym systemie dyżurów on-call, również poza standardowymi godzinami pracy — w nocy, weekendy i dni świąteczne. Szczegóły dotyczące organizacji oraz częstotliwości dyżurów zostaną ustalone podczas procesu rekrutacyjnego. Wymagania Backend: C#, .NET Framework, .NET Core, .NET 6+, ASP.NET MVC, ASP.NET Web API, REST API, Microservices Frontend: React, JavaScript ES6+, TypeScript, HTML5, CSS3, Material UI Cloud & DevOps: Microsoft Azure, Azure DevOps, CI/CD, Azure SQL, Cosmos DB, Docker Monitoring & Support: monitoring, observability, troubleshooting, application support Source Control: Git, GitHub, Azure Repos Ta rola nie jest dla Ciebie, ale masz znajomego, który by się sprawdził? Poleć go i zgarnij nawet 5000 zł. Referral Program: Talent from your network Nie zwlekaj i zaaplikuj już teraz!

🏢 Summary: Remote 12-month contract for a Full Stack Developer to build scalable .NET/React applications and deliver production AI-powered features. The role requires practical commercial AI implementation experience, including LLM integrations, RAG, agents, vector search, or intelligent automation. 🗂️ Requirements: 5+ years of commercial C#/.NET experience, Hands-on React and TypeScript experience, Experience building REST APIs, backend services, or microservices, Experience with Azure or another major cloud platform, Git and CI/CD experience, Practical production AI development experience, Experience integrating AI functionality into a commercial application or product, Polish and English communication skills 📃 Skills: C#, .NET, React, TypeScript, REST, Azure, Git, CI/CD, LLMs, RAG, AzureOpenAI, OpenAI, Embeddings, Microservices 🏢 Description: We are looking for an experienced Full Stack Developer (.NET / React) who has real, hands-on experience building AI-powered solutions or features . We are specifically looking for developers who have gone beyond simply using GitHub Copilot or other AI coding assistants . You should have actually designed, developed, integrated, or deployed AI functionality within a commercial application or product . Location: Remote – Poland Language: Polish and English Start: September 2026 Contract: 12 months Interview process: 1 interview only Key Responsibilities Design and develop full-stack applications using C# / .NET and React . Build scalable backend services, REST APIs and integrations. Design and implement AI-powered features as part of real applications or products. Integrate applications with LLMs and AI services such as Azure OpenAI, OpenAI or similar platforms. Work with technologies and concepts such as RAG, AI Agents, prompt orchestration, vector search, embeddings or intelligent automation , depending on the use case. Take AI solutions from idea/prototype through integration and production implementation . Work closely with architects, product owners and engineering teams. Required Skills 5+ years of commercial C# / .NET experience. Strong hands-on experience with React and TypeScript . Experience developing REST APIs, backend services and/or microservices . Azure or another major cloud platform. Git, CI/CD and modern software engineering practices. Strong Polish and English communication skills. AI Experience – Important We need someone with practical AI development experience , not only exposure to AI tools. You should have built or contributed to at least one solution involving areas such as: LLM integration within a commercial application. RAG (Retrieval-Augmented Generation) solutions. AI Agents / agentic workflows . Integration with Azure OpenAI, OpenAI APIs or similar AI platforms . Vector databases, embeddings or semantic search . AI-powered document processing, classification, extraction or summarisation. Intelligent workflow/process automation using AI. Custom AI assistants or conversational applications. Other production AI/ML functionality integrated into software products . We are interested in developers who can clearly explain what AI solution they built, what problem it solved, which technologies they used, and what their personal contribution was.

🏢 Summary: Senior Full Stack Engineer role focused on building scalable, business-critical web applications using React/Remix front ends and Python REST APIs. The position contributes to technical direction, engineering quality, DevOps practices, and mentoring within an agile, collaborative team. 🗂️ Requirements: Senior full-stack engineering experience, TypeScript, React, Python API development, MongoDB, SQL databases, Azure, Kubernetes, Clean, testable code, Automation, Vitest, Pytest, GitHub Actions, ArgoCD, CI/CD 📃 Skills: TypeScript, React, Remix, Python, REST, MongoDB, SQL, Azure, Kubernetes, AKS, Vitest, Pytest, GitHub, Actions, ArgoCD, CI/CD, DevOps 🏢 Description: We’re looking for a Senior Full Stack Engineer to join a collaborative, high-performing team building modern, business-critical web applications. In this role, you’ll work across React/Remix and Python APIs, helping shape technical direction, deliver scalable solutions, and improve engineering practices. We’re looking for someone who enjoys solving complex problems, writes clean and maintainable code, and thrives in an agile, team-oriented environment. What you’ll do Design, build, and deliver scalable full-stack applications Develop modern React/Remix front ends and Python REST APIs Improve performance, reliability, security, and accessibility Drive best practices in testing, DevOps, and continuous delivery Troubleshoot complex issues and implement long-term solutions Collaborate closely with product, architecture, and engineering teams Mentor other engineers and support a culture of learning and improvement What you’ll bring Strong experience as a Senior Full Stack Engineer Excellent TypeScript and React skills (Remix is a plus) Solid Python API development experience Experience with MongoDB and SQL databases Hands-on experience with Azure and Kubernetes (AKS) A strong focus on clean, testable code and automation Experience with Vitest, Pytest, GitHub Actions, ArgoCD, and CI/CD Great communication and collaboration skills If you’re excited by building scalable products, working with modern technologies, and having a genuine impact on both the platform and the engineering culture, we’d love to hear from you.

🏢 Summary: Full-time Senior Fullstack Software Engineer role focused on building scalable, cloud-native enterprise platform services with .NET and Angular or React. The position covers end-to-end feature delivery, microservices, architecture, CI/CD, production support, and mentoring in a hybrid Gdańsk-based setup. 🗂️ Requirements: 5+ years of commercial software development experience, Strong C# and .NET Core experience, ASP.NET, REST API, and microservices experience, Hands-on Angular or React experience, AWS, Docker, Kubernetes, SQL, Entity Framework, Git, and Azure DevOps knowledge, Automated testing and CI/CD pipeline experience, Modern software architecture and cloud-native development knowledge, English proficiency at B2+ level 📃 Skills: C#, .NET, ASP.NET, REST, Microservices, Angular, React, AWS, Docker, Kubernetes, SQL, EntityFramework, Git, AzureDevOps, CI/CD 🏢 Description: Senior Fullstack Software Engineer (.NET + Angular/React) Join a team building scalable, cloud-native platform services that power enterprise applications used by customers worldwide. We are looking for an experienced Fullstack Engineer with strong .NET expertise and solid frontend experience in Angular or React. Location: Gdańsk (Hybrid) Employment: Full-time, Employment Contract (UoP) Responsibilities Design and develop modern web applications using .NET and Angular or React . Build and enhance cloud-native, microservices-based solutions. Own features end-to-end, from technical design through development, testing, deployment, and support. Collaborate with cross-functional teams to deliver secure, scalable, and high-quality software. Contribute to architecture, CI/CD, automated testing, and engineering best practices. Support production environments and mentor other engineers. Requirements 5+ years of commercial software development experience. Strong experience with C#, .NET Core, ASP.NET, REST APIs , and microservices. Hands-on experience with Angular or React . Knowledge of AWS, Docker, Kubernetes, SQL, Entity Framework , Git, and Azure DevOps. Experience with automated testing and CI/CD pipelines. Good understanding of modern software architecture and cloud-native development. English level B2+ . What We Offer Employment contract (UoP). Hybrid work model from our Gdańsk office. Opportunity to work on a modern cloud platform using the latest technologies. International environment with experienced engineers and opportunities for professional growth.