Senior .NET Developer

🏢 Summary: B2B contract opportunity for a Senior Node.js Developer to design, build, and maintain scalable backend applications and APIs across diverse software projects, including AI-driven and legacy modernization initiatives. The role focuses on high-quality Node.js development, architecture contribution, and cloud-based deployments in Agile teams. 🗂️ Requirements: 5+ years of experience in Node.js development, Experience with Express.js or NestJS frameworks, Strong knowledge of JavaScript and TypeScript, Understanding of asynchronous programming and event-driven architecture, Experience building and integrating RESTful APIs, Experience with SQL and NoSQL databases, Experience with cloud platforms (AWS, Azure, or GCP), Knowledge of CI/CD pipelines, Experience with version control systems, Experience working in Agile/Scrum teams, English level B2 or higher, Experience with AI technologies and AI-powered features development 📃 Skills: Node.js, Express.js, NestJS, JavaScript, TypeScript, REST, SQL, NoSQL, PostgreSQL, MySQL, MongoDB, AWS, Azure, GCP, CI/CD, Git, AI 🏢 Description: Who we are: We are Inspeerity (part of DevelopX group), engineering consultancy providing software development and consultancy. Our primary expertise is systems architecture and full stack development – from defining project requirements, to designing, building, and deploying software applications for web, backend, enterprise and mobile. We are crazy about technology, serious about people. About position: We are currently building our talent pool for future Senior Node.js Developer roles. As our company is expanding, you may have the opportunity to work on a variety of software solutions across multiple initiatives, including projects we will be delivering in the future, from building native AI solutions to modernizing legacy systems. If you enjoy collaborating in a skilled team and are committed to delivering top-notch software, we’d love to connect. We're not prescriptive about background. Whether you've worked in fintech, SaaS, e-commerce, or enterprise systems — what matters is that you've shipped production software at scale, cared about its reliability, and learned from what broke. TL;DR • Who: Senior Node.js Developer • Contract Type: B2B Framework Agreement • Salary range: Up to 150 PLN/h • Company: Software House What you’ll be doing: • Designing, implementing, and maintaining high-quality Node.js applications. • Developing backend components and APIs to support scalable software solutions. • Collaborating with cross-functional teams. • Reviewing and refactoring code to ensure maintainability, performance, and security. • Participating in technical design discussions and contributing to architecture decisions. • Writing and maintaining technical documentation for systems, APIs, and processes. • Supporting deployment and integration of applications in different environments. You will be the best fit if you have: • 5+ years of experience as a Node.js developer, preferably with exposure to frameworks such as Express.js , NestJS , or similar. • Strong understanding of JavaScript/TypeScript, asynchronous programming, and event-driven architecture. • Experience with RESTful APIs and web services integration. • Familiarity with SQL and NoSQL databases (e.g., PostgreSQL, MySQL, MongoDB). • Experience with cloud environments such as AWS, Azure, or GCP. • Knowledge of CI/CD pipelines and version control systems. • Strong problem-solving skills and ability to troubleshoot complex issues. • Experience working in Agile/Scrum teams and contributing to iterative development. • English level B2 or higher. • Experience with AI technologies, including using AI tools for development and building AI-powered features or applications. What we offer • Remote work or working from our Bialystok, Warsaw, Rzeszow offices. It's up to you! • Collaboration with experienced and engaged people who will appreciate your work and support you whenever you need it 😊 • Hybrid and flexible cooperation model based on a B2B Framework Agreement. • Great working conditions and best equipment: Dell or MacBook, your choice. Good to know: We don’t require a degree. We don’t do whiteboard puzzles or trick questions. Our interview process is practical: a technical conversation, and a chat about how you work. We value direct communication and intellectual curiosity. If you’re someone who gets excited debugging a tricky concurrency issue - not because you have to, but because you want to understand it — we’ll get along well.

🏢 Summary: Offer for a Senior Frontend Developer specializing in Angular to design, build, and maintain scalable, high-quality web applications within diverse software projects. The role involves frontend architecture decisions, integration with backend services, and collaboration in Agile teams. Contract is B2B with remote flexibility and focus on delivering production-grade solutions. 🗂️ Requirements: 5+ years Frontend development experience, Strong Angular 2+ expertise, Proficiency in JavaScript and TypeScript, Knowledge of HTML5 and CSS3, Experience with NgRx or state management, Experience integrating REST APIs, Familiarity with Webpack, Vite, npm or yarn, Experience with testing frameworks, Knowledge of CI/CD pipelines, Proficiency with Git, Experience in Agile/Scrum, English B2 or higher, Experience with AI tools or AI-powered features 📃 Skills: Angular, JavaScript, TypeScript, HTML5, CSS3, NgRx, REST, Webpack, Vite, npm, yarn, Jasmine, Karma, Cypress, Git, CICD, Agile, Scrum, AI 🏢 Description: Who we are: We are Inspeerity (part of DevelopX group), engineering consultancy providing software development and consultancy. Our primary expertise is systems architecture and full stack development – from defining project requirements, to designing, building, and deploying software applications for web, backend, enterprise and mobile. We are crazy about technology, serious about people. About position: We are currently building our talent pool for future Senior Frontend Developer (Angular) roles. As our company is expanding, you may have the opportunity to work on a variety of software solutions across multiple initiatives, including projects we will be delivering in the future, from building native AI solutions to modernizing legacy systems. If you enjoy collaborating in a skilled team and are committed to delivering top-notch software, we’d love to connect. We're not prescriptive about background. Whether you've worked in fintech, SaaS, e-commerce, or enterprise systems - what matters is that you've shipped production software at scale, cared about its reliability, and learned from what broke. TL;DR • Who: Senior Frontend Developer (Angular) • Contract Type: B2B Framework Agreement • Salary range: Up to 140 PLN/h • Company: Software House What you’ll be doing: • Designing, implementing, and maintaining high-quality frontend applications using Angular. • Building responsive, user-friendly interfaces and reusable UI components. • Collaborating with cross-functional teams including backend developers, designers, and product stakeholders. • Reviewing and refactoring code to ensure maintainability, performance, and scalability. • Participating in technical design discussions and contributing to frontend architecture decisions. • Writing and maintaining technical documentation for components and frontend processes. • Supporting integration with backend services and APIs. You will be the best fit if you have: • 5+ years of experience as a Frontend Developer, with strong expertise in Angular (2+). • Strong understanding of JavaScript / TypeScript, HTML5, and CSS3. • Experience with state management solutions (e.g., NgRx) and component-based architecture. • Experience with RESTful APIs and integration with backend services. • Familiarity with modern frontend tooling (e.g., Webpack, Vite, npm/yarn). • Knowledge of performance optimization techniques and building scalable web applications. • Experience with testing frameworks (e.g., Jasmine, Karma, Cypress or similar). • Knowledge of CI/CD pipelines and version control systems (e.g., Git). • Strong problem-solving skills and attention to detail. • English level B2 or higher. • Experience working in Agile/Scrum teams and contributing to iterative development. • Experience with AI technologies, including using AI tools for development and building AI-powered features or applications. What we offer • Remote work or working from our Bialystok, Warsaw, Rzeszow offices. It's up to you! • Collaboration with experienced and engaged people who will appreciate your work and support you whenever you need it 😊 • Hybrid and flexible cooperation model based on a B2B Framework Agreement. • Great working conditions and best equipment: Dell or MacBook, your choice. Good to know: We don’t require a degree. We don’t do whiteboard puzzles or trick questions. Our interview process is practical: a technical conversation, and a chat about how you work. We value direct communication and intellectual curiosity. If you’re someone who gets excited debugging a tricky concurrency issue - not because you have to, but because you want to understand it — we’ll get along well.

🏢 Summary: Senior Frontend Developer (React) role focused on designing and delivering scalable, high-quality frontend applications using React and Next.js across diverse software projects, including AI-driven and legacy modernization initiatives. The position involves architectural decisions, performance optimization, API integration, and collaboration within cross-functional Agile teams. B2B contract with opportunity to work on production systems at scale. 🗂️ Requirements: 5+ years experience as Frontend Developer, Strong expertise in React, Proficiency in JavaScript, Proficiency in TypeScript, Strong knowledge of HTML5, Strong knowledge of CSS3, Experience with Next.js including SSR and SSG, Experience with state management libraries, Experience integrating RESTful APIs, Familiarity with modern frontend tooling, Experience with testing frameworks, Knowledge of CI/CD pipelines, Proficiency with Git, Experience working in Agile/Scrum, English level B2 or higher 📃 Skills: React, Next.js, JavaScript, TypeScript, HTML5, CSS3, Redux, Zustand, REST, Vite, Webpack, npm, yarn, Jest, ReactTestingLibrary, Cypress, CI/CD, Git, Agile, Scrum, AI 🏢 Description: Who we are: We are Inspeerity (part of DevelopX group), engineering consultancy providing software development and consultancy. Our primary expertise is systems architecture and full stack development – from defining project requirements, to designing, building, and deploying software applications for web, backend, enterprise and mobile. We are crazy about technology, serious about people. About position: We are currently building our talent pool for future Senior Frontend Developer (React) roles. As our company is expanding, you may have the opportunity to work on a variety of software solutions across multiple initiatives, including projects we will be delivering in the future, from building native AI solutions to modernizing legacy systems. If you enjoy collaborating in a skilled team and are committed to delivering top-notch software, we’d love to connect. e're not prescriptive about background. Whether you've worked in fintech, SaaS, e-commerce, or enterprise systems — what matters is that you've shipped production software at scale, cared about its reliability, and learned from what broke. TL;DR • Who: Senior Frontend Developer (React) • Contract Type: B2B Framework Agreement • Salary range: Up to 140 PLN/h • Company: Software House What you’ll be doing: • Designing, implementing, and maintaining high-quality frontend applications using React. • Building modern, responsive user interfaces and reusable components. • Working with frameworks like Next.js to deliver performant, scalable applications (including SSR/SSG when applicable). • Collaborating with cross-functional teams including backend developers, designers, and product stakeholders. • Reviewing and refactoring code to ensure maintainability, performance, and scalability. • Participating in technical design discussions and contributing to frontend architecture decisions. • Writing and maintaining technical documentation for components and frontend processes. • Supporting integration with backend services and APIs. You will be the best fit if you have: • 5+ years of experience as a Frontend Developer, with strong expertise in React. • Strong understanding of JavaScript / TypeScript, HTML5, and CSS3. • Experience building applications with frameworks such as Next.js, including server-side rendering and static generation. • Experience with state management approaches (e.g., Redux, Zustand, or similar). • Experience with RESTful APIs and integration with backend services. • Familiarity with modern frontend tooling (e.g., Vite, Webpack, npm/yarn). • Knowledge of performance optimization techniques and building scalable web applications. • Experience with testing frameworks (e.g., Jest, React Testing Library, Cypress or similar). • Knowledge of CI/CD pipelines and version control systems (e.g., Git). • Strong problem-solving skills and attention to detail. • English level B2 or higher. • Experience working in Agile/Scrum teams and contributing to iterative development. • Experience with AI technologies, including using AI tools for development and building AI-powered features or applications. What we offer • Remote work or working from our Bialystok, Warsaw, Rzeszow offices. It's up to you! • Collaboration with experienced and engaged people who will appreciate your work and support you whenever you need it 😊 • Hybrid and flexible cooperation model based on a B2B Framework Agreement. • Great working conditions and best equipment: Dell or MacBook, your choice. Good to know: We don’t require a degree. We don’t do whiteboard puzzles or trick questions. Our interview process is practical: a technical conversation, and a chat about how you work. We value direct communication and intellectual curiosity. If you’re someone who gets excited debugging a tricky concurrency issue - not because you have to, but because you want to understand it — we’ll get along well.

🏢 Summary: B2B contract role for a Senior Java Developer focused on designing and maintaining scalable backend systems and APIs across diverse software projects, including AI-driven and legacy modernization initiatives. The position involves architectural input, code quality improvements, and deployment support in cloud environments within Agile teams. 🗂️ Requirements: Minimum 5 years of experience as a Java Developer, Commercial experience with Spring Boot or Hibernate, Strong knowledge of object-oriented programming and design patterns, Experience building and integrating RESTful APIs, Experience with SQL and NoSQL databases, Experience with cloud platforms (AWS, Azure, or GCP), Knowledge of CI/CD pipelines and version control systems, Experience working in Agile/Scrum teams, English proficiency at B2 level or higher, Experience with AI technologies or AI-powered solutions 📃 Skills: Java, Spring, SpringBoot, Hibernate, REST, SQL, NoSQL, PostgreSQL, MySQL, MongoDB, AWS, Azure, GCP, CI/CD, Git, OOP, Scrum, AI 🏢 Description: About position: We are currently building our talent pool for future Senior Java Developer roles. As our company is expanding, you may have the opportunity to work on a variety of software solutions across multiple initiatives, including projects we will be delivering in the future, from building native AI solutions to modernizing legacy systems. If you enjoy collaborating in a skilled team and are committed to delivering top-notch software, we’d love to connect. We're not prescriptive about background. Whether you've worked in fintech, SaaS, e-commerce, or enterprise systems, what matters is that you've shipped production software at scale, cared about its reliability, and learned from what broke. Who we are: We are Inspeerity (part of DevelopX group), engineering consultancy providing software development and consultancy. Our primary expertise is systems architecture and full stack development – from defining project requirements, to designing, building, and deploying software applications for web, backend, enterprise and mobile. We are crazy about technology, serious about people. TL;DR • Who : Senior Java Developer • Contract Type : B2B Framework Agreement. • Salary range: Up to 150 PLN/h • Company : Software House What you’ll be doing: Designing, implementing, and maintaining high-quality Java applications. Developing backend components and APIs to support scalable software solutions. Collaborating with cross-functional teams. Reviewing and refactoring code to ensure maintainability, performance, and security. Participating in technical design discussions and contributing to architecture decisions. Writing and maintaining technical documentation for systems, APIs, and processes. Supporting deployment and integration of applications in different environments. You will be the best fit if you have: 5 years of experience as a Java developer, preferably with exposure to Spring Boot, Hibernate, or similar frameworks. Strong understanding of object-oriented programming, design patterns, and clean code principles. Experience with RESTful APIs and web services integration. Familiarity with SQL and NoSQL databases (e.g., PostgreSQL, MySQL, MongoDB). Experience with cloud environments such as AWS, Azure, or GCP. Knowledge of CI/CD pipelines and version control systems (e.g., Git). Strong problem-solving skills and ability to troubleshoot complex issues. English level B2 or higher. Experience working in Agile/Scrum teams and contributing to iterative development. Experience with AI technologies, including using AI tools for development and building AI-powered features or applications. What we offer : Remote work or working from our Bialystok, Warsaw, Rzeszow offices. It's up to you! Collaboration with experienced and engaged people who will appreciate your work and support you whenever you need it 😊 Hybrid and flexible cooperation model based on a B2B Framework Agreement. Great working conditions and best equipment: Dell or MacBook, your choose. Good to know: We don’t require a degree. We don’t do whiteboard puzzles or trick questions. Our interview process is practical: a technical conversation and a chat about how you work. We value direct communication and intellectual curiosity. If you’re someone who gets excited about debugging a tricky concurrency issue - not because you have to, but because you want to understand it — we’ll get along well.

🏢 Summary: Senior .NET Developer role focused on building and architecting cloud-native backend systems with AWS and CI/CD automation. The position involves designing microservices-based solutions, writing high-quality testable code, and contributing across the full project lifecycle in a spec-driven environment. Fully remote B2B contract with long-term cooperation potential. 🗂️ Requirements: Experience with modern .NET / .NET Core, Experience with AWS or Azure, Knowledge of microservices architecture, Knowledge of distributed systems, Ability to design system architecture, Experience writing integration tests, Experience writing end-to-end tests, Familiarity with BDD approach, Experience with CI/CD automation 📃 Skills: .NET, NETCore, AWS, Azure, CI/CD, Microservices, DistributedSystems, C#, BDD, IntegrationTesting, E2ETesting, Architecture 🏢 Description: Join an international IT company specializing in cloud services, managed services, and digital transformation for enterprises. As a Senior .NET Developer with a focus on AWS and CI/CD automation, you will participate in the project by providing backend support to the Tech Lead and a team. Key responsibilities Designing and architecting system components, Writing high-quality, testable code in .NET, Contributing to the development of modern cloud-native solutions, Working across the full project lifecycle (from discovery to delivery), Participating in planning and analysis (discovery, planning), Working in a “spec-driven” approach (based on specifications), Co-creating and refining specifications, acceptance criteria, and architectural decisions. Ideal candidate profile Experience with . NET (Core / modern .NET), Azure or AWS , Knowledge of architecture: microservices, distributed systems, Ability to translate business requirements into technical architecture, Writing integration and end-to-end tests, Familiarity with BDD (Behavior-Driven Development) approach. Conditions Type of cooperation: B2B contract Initial contract duration: 1st June- End of February 2027, with the intention to extend the cooperation or move top performers to another project. Rate: 130 - 160 PLN/h Benefits: Private healthcare, Multisport card and life insurance Work model: 100% remote from any location in Poland Recruitment steps Phone call with a Recruiter - Oliwia (approx. 20 min.) Interview with Client : Introductory conversation with the delivery team: review of your experience vs project needs, light technical questions, and verification of your comfort in a fully English‑speaking, international environment. Introductory interview : discussion of experience in relation to project requirements, technical questions. Final technical interview with Client : in‑depth technical questions, possibly practical task to see how you think, ask questions, and structure solutions. Decision and feedback

🏢 Summary: Remote Senior .NET Engineer role focused on developing, optimizing, and maintaining enterprise applications built on ASP.NET, .NET Core, and .NET Framework. The position involves performance tuning, database optimization, production troubleshooting, and contributing within a cross-functional agile team. Strong emphasis on system reliability, CI/CD practices, and collaboration in an English-speaking environment. 🗂️ Requirements: Bachelor’s degree in Computer Science or related field, Strong experience with .NET technologies (ASP.NET, .NET Core, .NET Framework), Solid experience with MSSQL databases and SQL, Experience with stored procedures and query optimization, Proven experience in debugging and performance optimization, Experience troubleshooting production systems, Familiarity with CI/CD tools (Jenkins, TeamCity, or Azure DevOps), Ability to work in cross-functional agile teams, Strong English communication skills 📃 Skills: C#, .NET, ASP.NET, MSSQL, SQL, StoredProcedures, Jenkins, TeamCity, AzureDevOps, CICD, Debugging, Performance, Git, DevOps 🏢 Description: Salary: up to 1300 PLN/MD on B2B Work model: remote Why choose this offer? Work in an agile and self-sufficient team with autonomy over development Collaborate with an English-speaking, multicultural team The client is one of the European leaders in its field and is building a completely new platform using the latest technologies The Jit community will bring you a nice time during regular integration meetings Enjoy work-life balance in a company that values flexibility and innovation Project We are looking for a highly skilled Senior .NET Engineer to join our dynamic team. In this role, you will focus on developing, improving, maintaining, troubleshooting, and optimizing applications built with ASP.NET, .NET Core, and .NET Framework. Your expertise in MSSQL databases, debugging, and performance improvement will be crucial in ensuring smooth system operations. Our teams follow a T-shaped, cross-functional setup , meaning engineers contribute beyond their primary expertise. You should be comfortable taking on small tasks in different areas , including bug fixes, PR reviews, or DevOps contributions . We value collaboration and adaptability over rigid role definitions. What you'll be doing Develop, improve, maintain and support applications developed in ASP.NET, .NET Core, and .NET Framework Identify and resolve software and database performance issues Optimize SQL queries and stored procedures to improve system efficiency Collaborate with cross-functional teams to debug and resolve production issues Implement performance improvements and ensure application reliability Work with build and deployment tools (e.g., Jenkins, TeamCity, Azure DevOps) Communicate progress and technical updates to stakeholders and team members Expected competences and knowledge Bachelor's degree in Computer Science, Engineering, or a related field Strong development experience in .NET technologies (ASP.NET, .NET Core, .NET Framework) Expertise in troubleshooting production system issues Solid experience with MSSQL databases, SQL, and stored procedures A proactive, problem-solving mindset Previous experience in debugging and performance optimization Familiarity with CI/CD tools such as Jenkins, TeamCity, or Azure DevOps Strong communication skills to interact with both technical and non-technical stakeholders Technologies you'll work with .NET Framework, .NET Core, ASP.NET MSSQL CI/CD Tools Debugging & Performance Optimization Version Control DevOps Contributions Client – why choose this particular client from the Jit portfolio? Our client is a Scandinavian supplier of software and services for purchasing and tendering processes in highly formalized conditions, such as orders in accordance with public procurement law at the level of the European Union or individual member states. The delivery center is located in Utrecht. Client’s platforms allow to announce tenders and conduct the entire procedure of collecting and evaluating offers at every stage of the purchasing process. They are used both by public administration bodies at various levels in European countries and by purchasing departments of large companies and corporations. About Jit Team The Human factor of IT - it's not just a slogan, it's a philosophy. The foundation of Jit Team is people, which is why we prioritise you. We employ over 500 experienced experts . We create highly specialised teams for clients from all over the world. We offer team members developmental projects, a wide range of benefits and a proprietary professional development programme. Behind our maxim are also charitable and educational activities. We support pupils and students by donating learning equipment. We offer internships to help launch careers in IT. We support water rescuers and hospitals by providing the necessary equipment. We are a Polish company and we share what we have achieved over 15 years of activity . By supporting indigenous initiatives, we ensure the circulation of good energy.

🏢 Summary: Senior Full-Stack Developer role focused on building a modern, headless e-commerce and marketing platform using cloud-based, composable architecture. The position involves end-to-end development across backend and frontend, CI/CD automation, and production support within a 12-month B2B contract. The project aims to deliver a fully personalized customer experience in the building materials industry. 🗂️ Requirements: Minimum 4 years experience with DotNet and ASPNETCore, Strong experience with C# and full-stack web development, Experience with SQLServer, Experience with Optimizely, Knowledge of software architecture and design patterns, Experience with CI/CD pipelines, Experience with TDD, Knowledge of web application security and performance principles, Experience with Kafka, Experience with Git and Gitflow 📃 Skills: DotNet, ASPNETCore, C#, SQLServer, Optimizely, Kafka, Webpack, TailwindCSS, Storybook, Chromatic, Rider, VisualStudio, Git, GitHub, Gitflow, React, CICD, TDD 🏢 Description: We are looking for an experienced Senior Full-Stack Developer (with Optimizely) to join the team of our client. The project focuses on building a modern e-commerce and marketing platform based on composable, headless, cloud architecture, with the goal of delivering a seamless and fully personalized end-to-end customer experience. Who we are: We are Inspeerity (part of DevelopX group), a modern software house, providing software development, consultancy, and maintenance services. We specialize in full stack development – from defining project requirements, to designing, building, and deploying software applications for web, backend, enterprise and mobile. We are crazy about technology, serious about people. TL;DR • Who : Senior Full-Stack Developer (with Optimizely) • Contract Type : B2B • Salary range: Up to 210 PLN/h + VAT • Start date : ASAP • Project lenght : ~12 months, with the possibility of extension. • Company : Software House • Project topic : Building Materials Industry What you’ll be doing: Developing scalable technical solutions. Building and maintaining automated build and deployment pipelines. Developing features across the full technology stack, from data access and business logic to the user interface. Writing unit tests, fixing bugs, and preparing documentation. Troubleshooting and resolving production issues. Collaborating closely with business stakeholders to translate requirements into effective technical solutions. You will be the best fit if you have: At least 4 years of practical experience working with Microsoft .NET / ASP. NET Core and SQL Server. Strong understanding of software architecture, design patterns, and engineering best practices. Hands-on experience in full-stack development using C# and web technologies. Solid knowledge of web application performance, quality standards, and security principles. Genuine interest in Generative AI and its application in optimizing and automating the software development lifecycle. Experience working in Agile environments, including CI/CD pipelines, TDD, and peer code reviews. In addition to the stack mentioned above, experience in working with Apache Kafka, Webpack, TailwindCSS, Storybook, Chromatic, Rider, Visual Studio, Git, Github, Gitflow. Experience with React is a plus. English level B2 or higher. What we offer Remote work model with occasional visits to our client's office in Poznań or Warsaw. B2B contract. You’ll join a collaborative team of 12 specialists. About process: Step 1 - Call with with someone from our People Team. Step 2 - Meeting with our .NET Team Lead as a technical interviewer. Step 3 - Final stage. A technical interview with the client-side representatives. Time for your turn! ;)

🏢 Summary: Senior .NET Developer role focused on designing, extending, and modernising critical banking and securities systems in a fully remote B2B model. The position involves full-stack development, system integration, and cloud scaling within distributed, business-critical environments. The role requires close collaboration with business stakeholders and ownership of end-to-end application delivery. 🗂️ Requirements: 5+ years experience as .NET / C# Developer, Experience in banking or investment banking sector, Full-stack development experience, Knowledge of SOLID design principles, Experience with document-based databases, Experience with event-driven messaging frameworks, Experience with unit and integration testing, End-to-end application development experience, Ability to work during UK business hours, Based in Poland 📃 Skills: .NET, C#, MongoDB, SOLID, Messaging, UnitTesting, IntegrationTesting, Docker, Kubernetes, Cloud 🏢 Description: Work model: 100% remote (candidates must be based in Poland) Contract type: B2B Industry: Banking / Investment Banking We are looking for an experienced Senior .NET Developer to join a distributed engineering team working on critical banking systems. The role focuses on extending and modernising applications used across securities and banking operations, with a strong emphasis on system design, scalability, and cloud transformation. You will work end-to-end on business-critical systems, closely collaborating with Business Analysts, without a separate QA team. A solid background in banking or financial services is essential. Main Responsibilities: Design, develop, and extend .NET-based systems supporting multiple banking entities Contribute to the integration of securities and core banking platforms Support and enhance a portfolio of ~17 applications across product control and risk management Work with an in-house development framework in a full-stack capacity Participate in scaling applications for cloud-based, containerized environments Collaborate closely with business stakeholders to deliver robust solutions Ensure high code quality through unit and integration testing Key Requirements: 5+ years of professional experience as a .NET / C# Developer Hands-on experience in the banking or investment banking sector (mandatory) Full-stack development experience (backend-focused, frontend included) Strong understanding and practical application of SOLID design principles Experience with document-based databases (e.g. MongoDB) Experience with event-driven / event-based messaging frameworks Solid knowledge of unit and integration testing Experience working end-to-end on applications (development, testing, support) Ability to work independently in a fast-paced, regulated environment Availability during UK business hours Nice to Have: Experience with cloud platforms and application migration to cloud Experience with container technologies (e.g. Docker, Kubernetes) Exposure to systems such as Murex or large in-house banking platforms Background in securities, risk, or product control systems Other Details: This role is 100% remote with candidates required to be located in Poland. The contract is on a B2B basis within the banking and investment banking industry.

🏢 Summary: Senior .NET Developer role focused on designing, extending, and modernizing critical banking systems within securities and core banking domains. The position involves full-stack development, system integration, and cloud scaling in a distributed team without a separate QA function. Work includes end-to-end ownership of business-critical applications in a regulated investment banking environment. 🗂️ Requirements: 5+ years experience with .NET and C#, Hands-on experience in banking or investment banking, Full-stack development experience, Strong knowledge of SOLID principles, Experience with document-based databases, Experience with event-driven messaging frameworks, Knowledge of unit and integration testing, End-to-end application development experience, Ability to work independently in regulated environments, Availability during UK business hours, Poland-based residency 📃 Skills: .NET, C#, MongoDB, SQL, REST, Microservices, Docker, Kubernetes, Azure, UnitTesting, IntegrationTesting, EventDriven, Git 🏢 Description: Work model: 100% remote (candidates must be based in Poland) Contract type: B2B Industry: Banking / Investment Banking We are looking for an experienced Senior .NET Developer to join a distributed engineering team working on critical banking systems. The role focuses on extending and modernising applications used across securities and banking operations, with a strong emphasis on system design, scalability, and cloud transformation. You will work end-to-end on business-critical systems, closely collaborating with Business Analysts, without a separate QA team. A solid background in banking or financial services is essential. Main Responsibilities: Design, develop, and extend .NET-based systems supporting multiple banking entities Contribute to the integration of securities and core banking platforms Support and enhance a portfolio of ~17 applications across product control and risk management Work with an in-house development framework in a full-stack capacity Participate in scaling applications for cloud-based, containerized environments Collaborate closely with business stakeholders to deliver robust solutions Ensure high code quality through unit and integration testing Key Requirements: 5+ years of professional experience as a .NET / C# Developer Hands-on experience in the banking or investment banking sector (mandatory) Full-stack development experience (backend-focused, frontend included) Strong understanding and practical application of SOLID design principles Experience with document-based databases (e.g. MongoDB) Experience with event-driven / event-based messaging frameworks Solid knowledge of unit and integration testing Experience working end-to-end on applications (development, testing, support) Ability to work independently in a fast-paced, regulated environment Availability during UK business hours Nice to Have: Experience with cloud platforms and application migration to cloud Experience with container technologies (e.g. Docker, Kubernetes) Exposure to systems such as Murex or large in-house banking platforms Background in securities, risk, or product control systems Other Details: This role is 100% remote with candidates required to be located in Poland. The contract is on a B2B basis within the banking and investment banking industry.

🏢 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