Senior Fullstack .NET Engineer

🏢 Summary: The role involves developing and maintaining scalable full-stack web applications using .NET and modern frontend frameworks. You will design robust Web APIs, optimize databases, and implement clean, testable code within CI/CD-driven environments. The position requires active participation in the full software development lifecycle for international projects. 🗂️ Requirements: Minimum 3 years commercial experience with .NET (C#, Web API, Entity Framework), Proficiency in Angular or React, Strong knowledge of JavaScript, HTML, CSS, Experience with SQL Server or PostgreSQL, Understanding of Unit Testing, Experience with Git, Experience with CI/CD pipelines, Knowledge of design patterns, Knowledge of software development best practices, Fluent English (min. B2), Availability for hybrid work mode 📃 Skills: .NET, C#, WebAPI, EntityFramework, Angular, React, JavaScript, HTML, CSS, SQL, SQLServer, PostgreSQL, UnitTesting, Git, CI/CD 🏢 Description: As a member of our development team, you will be responsible for building scalable web applications, designing robust APIs, and creating intuitive user interfaces. We value clean code, analytical thinking, and a proactive approach to technology. Our expectations: Minimum 3 years of commercial experience in .NET (C#, Web API, Entity Framework). Proficiency in Angular or React, along with JavaScript, HTML, CSS, and modern frontend libraries. Strong experience with relational databases such as SQL Server or PostgreSQL. Solid understanding of Unit Testing, Git, and CI/CD pipelines. Practical knowledge of design patterns and software development best practices. A collaborative mindset and the ability to explain complex technical issues clearly. Strong analytical skills and a "get it done" attitude. Fluent English (min. B2) for smooth collaboration with international partners. Open to work in hybrid mode. Main responsibilities: You will design, develop, and maintain scalable full-stack applications using .NET and modern frontend frameworks (Angular/React) for diverse client projects. You will be responsible for writing clean, testable code and implementing unit tests to ensure the highest software performance and reliability. You will work closely with cross-functional teams to architect robust Web APIs and optimize database schemas while following industry best practices and design patterns. You will actively participate in the full software development life cycle, including CI/CD processes and version control management, to ensure seamless project delivery.

🏢 Summary: Short-term contract for an experienced .NET Developer to design and build scalable backend systems in the energy and logistics domain using a microservices architecture. The role focuses on developing REST APIs, system architecture, integrations, and data optimization in high-scale production environments. Strong emphasis on AI-assisted development and modern DevOps practices. 🗂️ Requirements: 4–5+ years experience as .NET Developer, .NET 8 proficiency, ASP.NET Core API expertise, Entity Framework Core knowledge, SQL Server proficiency, Experience with Redis, Experience with RabbitMQ, Experience with Docker, Understanding of DDD, Experience with microservices architecture, Experience with xUnit testing, Hands-on use of AI tools in development 📃 Skills: .NET, ASP.NET, C#, EntityFramework, SQLServer, Redis, RabbitMQ, Docker, xUnit, Microservices, DDD, REST, AI 🏢 Description: About the project You’ll be working on backend systems within the energy and logistics domain , focusing on scalable platforms supporting services such as charging infrastructure, terminal operations, and logistics solutions. The systems are built using a modern microservices architecture , with strong emphasis on scalability, performance, and integrations. Duration: ~3 months (with possible extension) Your role Design and develop backend applications using .NET 8 Build and maintain REST APIs ( ASP.NET Core) Work on system architecture (including DDD and microservices ) Integrate systems using RabbitMQ Optimize and manage data storage ( SQL Server, Redis ) Write and maintain unit tests ( xUnit ) Containerize applications using Docker Actively use AI tools in daily development (must-have) Collaborate with developers, PMs, and designers Requirements 4–5+ years of experience as a .NET Developer Strong knowledge of: .NET 8 ASP.NET Core API Entity Framework Core SQL Server Experience with: Redis RabbitMQ Docker Understanding of DDD and system architecture Experience working with microservices Experience with testing ( xUnit ) Hands-on experience using AI tools in development (required) Nice to have Experience in energy, logistics, or high-scale systems Experience building high-availability solutions Experience working in distributed teams What we offer Opportunity to work on large-scale, production systems Flexible B2B cooperation Real impact on architecture and technical decisions Possibility to extend cooperation after the initial contract Work environment where AI is an integral part of development

🏢 Summary: Development of backend applications using .NET/.NET Core in a banking environment, including building REST APIs, business logic modules, and system integrations. The role involves working in AWS to deploy serverless and containerized services, managing SQL databases, and ensuring security and regulatory compliance. Close collaboration with business teams is required to deliver high-quality, secure financial solutions. 🗂️ Requirements: Minimum 6 years of experience as .NET Developer, Strong knowledge of .NET and C#, Hands-on experience with AWS services (Lambda, ECS/EKS, S3, RDS), Experience with REST API development, Proficiency in Kafka, Proficiency in SQL and database design, Experience with containerization, Experience in banking or financial projects, Understanding of security and regulatory requirements, Very good English skills 📃 Skills: .NET, C#, AWS, Lambda, ECS, EKS, S3, RDS, Kafka, SQL, REST, Docker, Kubernetes 🏢 Description: Scope of Responsibilities: Design and development of backend applications based on .NET / .NET Core. Creation and maintenance of REST APIs, integrations, and business logic modules. Working in an AWS environment – building and deploying serverless services, containerization, and process automation. Working with SQL databases (data model design, query optimization). Collaboration with analysts and business teams within the banking domain. Ensuring code quality, application security, and compliance with financial sector regulatory requirements. Requirements: Minimum 6 years of experience as a .NET Developer. Strong knowledge of .NET / .NET Core (C#). Hands-on experience with AWS (Lambda, ECS/EKS, S3, RDS, or other services). Proficiency in Kafka and SQL. Experience in banking or financial projects (knowledge of regulatory processes, security, and system integrations is a plus). Very good command of English (daily communication).

🏢 Summary: Software development role focused on building and maintaining .NET-based solutions, designing scalable architectures, and collaborating with stakeholders in an Agile environment. The position involves end-to-end development, REST API integration, SQL Server database design, code quality practices, and continuous improvement initiatives. 🗂️ Requirements: 3+ years of experience with .NET 4.8+, Experience with .NET Core, Knowledge of Microsoft SQL Server, Experience with relational database design, Advanced SQL skills, Understanding of OOP principles, Knowledge of clean architecture design patterns, Experience building and consuming REST APIs, Proficiency with Visual Studio, Proficiency with VS Code, Experience with GitLab, Understanding of DevOps practices, English proficiency at C1 level 📃 Skills: .NET, .NETCore, SQL, SQLServer, OOP, REST, VisualStudio, VSCode, GitLab, DevOps, eFront, WebSphereTX, Agile, Scrum 🏢 Description: Key Responsibilities End-to-End Development: Design logical data models and build robust software solutions aligned with a well-defined, multi-year product roadmap. Technical Design & Innovation: Proactively propose innovative architectural enhancements through controlled proof-of-concepts (spikes) and ensure all solutions adhere to modern software security standards. Collaboration & Delivery: Work hand-in-hand with business stakeholders to translate functional requirements into efficient technical specs. Participate in workload estimation, planning, and proactive status reporting. Code Quality & Mentorship: Maintain high engineering standards by conducting thorough peer code reviews, ensuring excellent test coverage, and managing application source code configuration. Team & Culture: Foster a friendly, supportive environment focused on continuous learning, knowledge-sharing, and team-wide upskilling. Requirements Technical Expertise: 3+ years of professional experience working with .NET 4.8+ and .NET Core . Strong knowledge of Microsoft SQL Server , relational database design (ER models), and advanced SQL. Solid grasp of Object-Oriented Programming ( OOP ) principles and clean architecture design patterns. Hands-on experience building and consuming REST APIs . Proficiency with development and version control tools ( Visual Studio, VS Code, GitLab ). Soft Skills & Methodology: A proactive, problem-solving mindset with a collaborative, team-player attitude. Foundational understanding of DevOps practices. Fluency in English (minimum C1) , with strong written and verbal communication skills. Nice to Have Direct development or configuration experience with the eFront FIA platform (highly advantageous). Familiarity with WebSphere TX . Prior experience working within an Agile/Scrum framework.

🏢 Summary: Short-term contract role for a .NET Developer to build and maintain scalable backend systems in the energy and logistics domain using microservices architecture. The work focuses on developing REST APIs, system integrations, and high-performance services with modern technologies. The project emphasizes AI-supported development and offers potential extension and growth into architectural responsibilities. 🗂️ Requirements: 2.5–4+ years of experience as a .NET Developer, Strong knowledge of .NET 8, Strong knowledge of ASP.NET Core API, Experience with Entity Framework Core, Experience with SQL Server, Experience with Redis, Experience with RabbitMQ, Experience with Docker, Understanding of microservices architecture, Basic knowledge of DDD, Experience writing unit tests (xUnit or similar), Ability to work with partially documented systems and integrations, Hands-on experience using AI tools in development 📃 Skills: .NET, ASP.NET, EntityFramework, SQLServer, Redis, RabbitMQ, Docker, xUnit, Microservices, DDD, REST, AI 🏢 Description: About the project You’ll be working on backend systems within the energy and logistics domain , focusing on scalable platforms supporting services such as charging infrastructure, terminal operations, and logistics solutions. The systems are built using a modern microservices architecture , with strong emphasis on scalability, performance, and integrations. Duration: ~3 months (with possible extension) Your role Develop and maintain backend applications using .NET 8 Build and extend REST APIs ( ASP.NET Core) Support system architecture design (DDD, microservices) Work on integrations with internal systems Use RabbitMQ for communication between services Work with databases ( SQL Server, Redis ) Write unit tests ( xUnit ) Containerize applications using Docker Use AI tools in daily development (must-have) Collaborate with team members and support technical discussions Requirements 2.5–4+ years of experience as a .NET Developer Good knowledge of: .NET 8 ASP.NET Core API Entity Framework Core SQL Server Experience with: Redis RabbitMQ Docker Understanding of microservices architecture and DDD basics Experience writing tests ( xUnit or similar) Ability to work with partially documented systems and integrations Hands-on experience using AI tools in development (required) Nice to have Experience with complex integrations Experience in logistics / energy / enterprise systems Exposure to system design discussions What we offer Work on real, large-scale systems Flexible B2B cooperation Opportunity to grow into more senior/architectural responsibilities Possibility to extend cooperation after the initial contract Work environment where AI is part of daily development

🏢 Summary: The offer is for a .NET Developer to design, develop, and maintain modern web applications and RESTful APIs using Microsoft technologies. The role focuses on ASP.NET Core development, API-first design, Optimizely CMS customization, and ensuring performance, security, and scalability. It also involves contributing to CI/CD processes and reusable component development. 🗂️ Requirements: Strong experience with C# and .NET, Hands-on experience with ASP.NET Core MVC, Experience with Web APIs, Experience designing and consuming REST APIs, Knowledge of OpenAPI/Swagger, Experience with NuGet package management, Experience with Optimizely CMS, Knowledge of JavaScript, Knowledge of TypeScript, Knowledge of HTML, Knowledge of CSS, Experience with Git 📃 Skills: C#, .NET, ASP.NET, MVC, WebAPI, REST, OpenAPI, Swagger, NuGet, Optimizely, Episerver, JavaScript, TypeScript, HTML, CSS, Git, Azure, Docker, React, Angular 🏢 Description: Summary: We are looking for a skilled .NET Developer to support our engineering team in the development and maintenance of modern web applications and APIs. This role is vital for enhancing digital experiences, leveraging Microsoft technologies, and ensuring optimal performance of our systems. Responsibilities: Design, develop, test, and maintain applications using .NET and ASP.NET Core. Develop and enhance RESTful APIs following API-first design principles. Create, maintain, and consume OpenAPI (Swagger) specifications. Build web applications utilizing ASP.NET Core MVC and Web API frameworks. Customize solutions using Optimizely (Episerver) CMS and Commerce platforms. Implement content models and components within Optimizely. Design reusable libraries and manage package publishing through NuGet. Collaborate with architects, product owners, and UX designers to provide quality solutions. Participate in code reviews, testing, and performance optimization. Contribute to CI/CD pipelines and deployment automation. Ensure security, scalability, and reliability in applications. Must Haves: Strong experience with C# and .NET development. Hands-on experience with ASP.NET Core MVC and Web APIs. Experience designing and consuming REST APIs. Strong knowledge of OpenAPI/Swagger specifications. Experience with NuGet package management. Experience with Optimizely (Episerver) CMS. Good knowledge of JavaScript, TypeScript, HTML, and CSS. Experience with Git. Nice to Haves: Experience with Optimizely Commerce and its features. Experience with Azure Cloud Services. Knowledge of Docker. Experience with automated testing frameworks. Understanding of microservices architecture. Familiarity with frontend frameworks like React or Angular.

🏢 Summary: The offer is for a Full Stack .NET Developer responsible for building scalable backend services and RESTful APIs within domain-driven and event-driven architectures, as well as developing responsive frontend interfaces. The role involves working with microservices or modular monoliths, implementing asynchronous integrations, and ensuring high code quality through testing and CI/CD practices. The position requires close collaboration in an agile environment and contribution to architectural decisions. 🗂️ Requirements: Minimum 3 years of experience in similar role, Very good knowledge of ASP.NET WebAPI (.NET Core), Very good knowledge of React, Very good knowledge of TypeScript, Experience with Unit Testing, Very good knowledge of Git, Very good knowledge of SQL Server or Azure SQL, Experience with EF Core, Experience with CI/CD pipelines, Experience with containerised deployments, Experience with event-driven architecture, Good command of English 📃 Skills: C#, .NET, ASP.NET, WebAPI, React, TypeScript, SQL, SQLServer, AzureSQL, EFCore, Git, CI/CD, Docker, Microservices, REST, UnitTesting 🏢 Description: Responsibilities: Designing and implementing scalable backend services and RESTful APIs within a domain-driven and event-driven architecture context, including both modular monolith and microservices approaches Building and maintaining responsive frontend interfaces, ensuring seamless integration with backend systems Contributing to architectural decisions and participating in collaborative design sessions to align technical solutions with business requirements Writing and maintaining unit, integration, and end-to-end tests. Ensuring code quality through thorough code reviews and adherence to team standards Working with CI/CD pipelines, containerised deployments, and infrastructure as code Implementing asynchronous communication patterns and event-based integrations between services Configuring and utilising monitoring and observability tools for application diagnostics and performance analysis Collaborating within an agile team, working closely with business analysts to refine requirements, and actively participating in sprint ceremonies Requirements: At least 3 years of experience on a similar position Very good knowledge of ASP.NET WebAPI (.NET Core) Very good knowledge of React, TypeScript Very good knowledge or experience in Unit Testing and GIT Very good knowledge of SQL Server/Azure SQL, EF Core Good command of English Offer: Constant support of dedicated consultant Employee referral program

🏢 Summary: The offer is for a Senior .NET Developer responsible for improving and refactoring core backend systems to enhance structure, maintainability, and security. The role focuses on reducing technical debt, enabling automation and AI integration, and ensuring high code quality through testing and CI/CD practices. The position involves hands-on development within legacy or monolithic environments and driving system modernization. 🗂️ Requirements: 5+ years experience in .NET / C# backend development, Experience with legacy or monolithic systems, Strong knowledge of clean code principles, Proven experience in refactoring existing codebases, Strong SQL and backend integration experience, Experience with APIs and service-based architecture, Experience with CI/CD pipelines, Experience with automated testing, Familiarity with TDD or BDD practices, Experience with Gherkin, SpecFlow, Cucumber or similar, Experience using AI tools in development workflows, Understanding of code structuring for automation and AI integration 📃 Skills: .NET, C#, SQL, APIs, CI/CD, TDD, BDD, Gherkin, SpecFlow, Cucumber, AI, Git, Docker, .NETCore 🏢 Description: Introduction & Summary: We are seeking a Senior .NET Developer with 5-8+ years of experience in backend development and .NET engineering. The successful candidate will drive improvement in code quality, reduce technical debt, and support system structuring for better predictability. With a focus on future automation and AI capabilities, you will help ensure code understandability, maintainability, and security. Main Responsibilities: Responsible for hands-on development and refactoring of core systems, with the aim of enhancing their structure and predictability. Develop and improve .NET-based systems. Reduce technical debt and increase maintainability. Support safe and efficient delivery. Ensure code is understandable, maintainable, and secure. Make systems testable and observable. Facilitate automation of workflows. Key Requirements: Strong experience with .NET / C#. Experience working with legacy or monolithic systems. Strong understanding of clean code principles. Experience with refactoring and improving existing codebases. Strong SQL and backend integration experience. Experience with APIs and service-based architecture. Experience with CI/CD pipelines. Experience with automated testing. Familiarity with TDD / BDD and security by design thinking. Experience with Gherkin / SpecFlow / Cucumber or similar. AI-related: Experience using AI tools in development workflows. Understanding of code structuring for automation and AI integration. Experience using AI for debugging, testing, or documentation support. Nice to Have: Experience with .NET Core. Experience with containerization. Exposure to AI-assisted testing or development tools. Experience improving system observability.

🏢 Summary: Architect-level role focused on designing and leading the implementation of scalable, enterprise-grade web applications using .NET and React in a global environment. The position combines hands-on development with architectural ownership across backend, frontend, cloud, and DevOps domains. Responsibilities include defining standards, ensuring scalability and security, and guiding distributed teams in delivering high-quality solutions. 🗂️ Requirements: Extensive experience with .NET / .NET Core in enterprise environments, Strong expertise in React and modern frontend ecosystems, Experience designing distributed systems and microservices architectures, Experience building scalable backend systems and RESTful APIs, Knowledge of TypeScript and state management libraries, Experience with CI/CD pipelines and DevOps practices, Cloud experience with Azure, Understanding of UX/UI principles and responsive design, Ability to define architecture standards and conduct code reviews, Professional English communication skills 📃 Skills: .NET, ASP.NET, React, TypeScript, Azure, REST, Microservices, CI/CD, DevOps, UX, UI 🏢 Description: We are seeking an experienced .NET & React Architect to lead the design and implementation of scalable, enterprise-grade web applications within a global environment. This role combines hands-on technical leadership with architectural ownership across backend and frontend domains, including strong alignment with UX/UI best practices. The successful candidate will define architectural standards, ensure system scalability and security, and support distributed development teams in delivering high-quality digital solutions. Key Responsibilities Define and oversee end-to-end solution architecture using .NET (Core/6+) and React Design scalable backend systems, APIs, and microservices Establish frontend architecture standards, component strategies, and state management patterns Ensure performance, security, maintainability, and scalability across applications Align technical solutions with UX/UI best practices, accessibility, and responsive design Provide architectural guidance, conduct code reviews, and mentor development teams Collaborate with product, UX/UI, and global stakeholders Support cloud-native architecture and DevOps practices (Azure preferred) Required Skills & Experience Extensive experience with .NET / .NET Core in enterprise environments Strong expertise in React and modern frontend ecosystems Proven experience designing distributed systems and microservices architectures Solid understanding of UX/UI principles and user-centered design Experience with RESTful APIs and system integrations Knowledge of TypeScript, state management libraries, and modern frontend tooling Experience with CI/CD pipelines and DevOps practices Cloud experience (Azure preferred) Strong communication skills in English Nice to Have Experience building or maintaining design systems Experience in global or distributed teams Strong background in performance optimization and security best practices What We Offer Long-term B2B engagement Competitive daily rate Participation in international, enterprise-scale projects Hybrid working model in Kraków Opportunity to shape architectural direction in a global organization If you meet the above criteria and are interested in long-term architectural ownership within a global environment, we encourage you to apply.

🏢 Summary: Backend-focused role involving development of scalable web applications using Java and React/Next.js. The position includes building and optimizing server-side components, APIs, and databases while ensuring performance and security. Close collaboration with cross-functional teams and end-to-end responsibility for backend quality and scalability are expected. 🗂️ Requirements: Minimum 4 years experience in similar role, Proficiency in Java server-side programming, Strong knowledge of React and Next.js, Experience with React Router and Redux, Experience with MySQL, PostgreSQL or MongoDB, Experience building scalable web applications, Knowledge of web performance and security principles, Experience with Git version control, Ability to conduct testing and debugging, English level B2 or higher 📃 Skills: Java, React, Next.js, Redux, ReactRouter, MySQL, PostgreSQL, MongoDB, SQL, NoSQL, API, REST, Git, AWS, Azure, GCP, Docker, NodeJS, Security, Testing 🏢 Description: Responsibilities: Designing, developing, and maintaining the server-side logic of web applications Implementing scalable and efficient server-side components and APIs Build React/Next.js based applications Working with relational and/or NoSQL databases to store and retrieve data efficiently Designing and optimizing database schemas for performance and scalability Integrating third-party APIs and web services to enhance application functionality Developing custom APIs to facilitate communication between front-end and back-end systems Implementing security best practices to protect against common web application vulnerabilities Conducting regular security audits and implement necessary measures Optimization: optimizing server-side code for maximum speed and scalability Monitoring and troubleshooting performance issues Collaborating with front-end developers, UI/UX designers, and other team members to ensure seamless integration of components Using version control systems (e.g., Git) to manage and track changes to the codebase Conducting thorough testing of server-side components to identify and fix bugs Collaborating with QA engineers for comprehensive testing Clear and comprehensive documentation for back-end systems and APIs Requirements: At least 4 years of experience in a similar position Proficiency in Java server-side programming Thorough understanding of React/Next.js core principles along with React router, hooks, Redux (or the like) workflows, Web performance and security Experience with database systems (e.g., MySQL, PostgreSQL, MongoDB) Proven experience in back-end development and building scalable web applications Strong analytical and problem-solving skills with attention to detail Effective communication skills to collaborate with cross-functional teams Ability to adapt to changing project requirements and technologies English at least B2 Nice to have: Familiarity with cloud platforms (e.g., AWS, Azure, GCP) Previous experience in Front-end development with Docker Experience with NodeJS Offer: Private medical care Co-financing for the sports card Constant support of dedicated consultant Employee referral program