Senior .Net Developer

🏢 Summary: Senior .NET Developer role on a long-term, fully remote B2B project for an insurance and reinsurance client. The position focuses on developing and modernizing business-critical applications for migration to Microsoft Azure, using .NET, Blazor, SQL Server, Azure Functions, and Azure DevOps. 🗂️ Requirements: 5+ years of commercial .NET development experience, Commercial C# and .NET experience, Commercial Blazor experience or strong Full Stack experience with willingness to learn Blazor, SQL Server experience, Microsoft Azure experience, Azure Functions experience, Azure DevOps experience, English proficiency at B2 level or higher, Independent, proactive work in an Agile environment, Strong problem-solving and ownership mindset 📃 Skills: C#, .NET, Blazor, SQLServer, Azure, AzureFunctions, AzureDevOps, Agile 🏢 Description: We are looking for an experienced Senior .NET Developer to join a long-term project delivered for a well-established UK-based client from the insurance and reinsurance sector. You will become part of an international delivery team responsible for developing and modernizing business-critical applications as part of the client's ongoing migration to the Microsoft Azure ecosystem. 📍 100% Remote (Poland) 🚀 Start: Beginning of August 📅 6-month contract with possible extension 💼 B2B Requirements: Minimum 5 years of commercial experience as a .NET Developer Strong hands-on experience with C# and .NET Commercial experience with Blazor (or strong Full Stack experience with willingness to learn Blazor) Experience working with SQL Server Practical experience with Microsoft Azure Experience developing Azure Functions Experience working with Azure DevOps Very good English communication skills (minimum B2 ) Ability to work independently and proactively in an Agile environment Strong problem-solving skills and ownership mindset Nice to have: Experience in the insurance or financial services industry Experience working in distributed international teams Knowledge of Scrum or Kanban Experience with application modernization or cloud migration projects Familiarity with legacy application modernization Responsibilities: Design, develop, and deliver software solutions based on business and technical requirements Develop and maintain applications using .NET, Blazor, SQL Server, and Microsoft Azure Build and maintain Azure Functions and cloud-based services Participate in technical discussions and contribute to solution design Collaborate closely with developers, testers, architects, Product Owners, and business stakeholders Ensure high-quality, maintainable, and scalable code Take ownership of assigned user stories from development through delivery Support the modernization of legacy applications into the Azure ecosystem Participate in Agile ceremonies and work closely with distributed international teams We offer: Up to 110 PLN/h net on B2B 100% remote work 14-day invoice payment terms Private healthcare package Access to the MyBenefit cafeteria platform (including MultiSport and gift cards) Long-term cooperation with an international UK client Opportunity to work on large-scale Azure modernization projects Collaborative environment with experienced engineering teams and modern development practices

🏢 Summary: Senior .NET Developer role focused on building and maintaining scalable back-end services for an electronic-component selection system and manufacturer database integrations. The position involves Azure and CosmosDB development, test automation, AI-assisted engineering, and close Agile collaboration with a US-based team. 🗂️ Requirements: 8+ years of .NET development experience, Senior-level problem-solving capabilities, C# experience, Azure cloud experience, CosmosDB experience, Practical use of AI development tools, Fluent English, Availability for daily meetings between 17:00 and 19:00 CET, Residence in Poland or eligibility to work in Poland 📃 Skills: .NET, C#, Azure, CosmosDB, Playwright, Selenium, GitHub, Copilot, ChatGPT, Cursor, Agile 🏢 Description: Your responsibilities - Design, develop, and maintain high-performance back-end services using .NET and C# for an established, scalable system used for selecting electronic components and integrating with manufacturer databases. - Work extensively with Azure cloud services and CosmosDB to build, maintain, and monitor resilient solutions. - Set up test automation structures and frameworks from scratch using tools such as Playwright or Selenium. - Actively use AI coding assistants, including GitHub Copilot, ChatGPT, or Cursor, to enhance productivity and troubleshooting; proactively share AI-assisted development practices with the team. - Collaborate directly with the US-based team in an Agile environment, participating in code reviews, sprint planning, and architectural discussions. - Communicate with business stakeholders to understand requirements and translate them into effective technical solutions. Requirements - Minimum 8 years of professional experience in .NET development, demonstrating a senior-level mindset and problem-solving capabilities. - Experience with C#, the Azure cloud ecosystem, and CosmosDB. - Practical experience using modern AI tools in daily software development and willingness to promote these practices. - Fluency in English to ensure seamless communication with US managers and developers. - Flexibility to align with US working hours, including daily meetings between 17:00 and 19:00 CET. - Residence in Poland and/or eligibility to work in Poland. Nice to have - Background or interest in Electrical Engineering. - General understanding of testing practices, CI/CD pipelines, and Git version control. - Knowledge of TypeScript or JavaScript. What we offer - 100% remote work. - Work in a Scandinavian culture built on logic and dialogue. - Health and sports benefits tailored to your needs. - Speed Coaching: short sessions that provide new perspectives and solutions. - Sports training, an internal team, and opportunities to take part in competitions. - Team events and development-focused meetups.

🏢 Summary: Senior .NET Developer role focused on transforming a data-intensive analytical platform for the cloud. The position involves scalable architecture design, legacy modernization, SOA-based development, user support, and close collaboration with engineering, analysis, and QA teams. 🗂️ Requirements: 5+ years of .NET software development experience, Web services design and implementation expertise, AWS and cloud environment experience, Redux and Context API mastery in React applications, Software design principles and best practices, Advanced English 📃 Skills: .NET, AWS, React, Redux, Context, SOA, Webservices 🏢 Description: We are looking for a Senior .NET Developer to join our team and contribute to the cloud transformation of a data-intensive analytical platform. In this role, you will collaborate with innovative and diverse professionals from around the world, designing scalable architectures and modernizing legacy components to ensure performance and reliability. Your tasks Contributing to the cloud transformation of a data-intensive analytical platform by designing scalable architectures and modernizing legacy components Ensuring continuous technological evolution of the product by proposing and implementing modern frameworks and architectural improvements Applying Service Oriented Architecture (SOA) concepts in software design and development Providing timely and courteous support to platform users, ensuring issues are understood, analyzed, and resolved promptly Collaborating closely with a team of software engineers, analysts, and quality engineers to design and build software solutions that meet business needs Adhering to team design and coding procedures and standards Requirements Minimum 5 years of experience in software development with a strong focus on .NET technologies Deep expertise in designing and implementing web services Practical experience with AWS and cloud environments Hands-on mastery of Redux and Context API in React applications Strong understanding of software design principles and best practices Advanced level of English Nice-to-have requirements Experience with C#

🏢 Summary: Hands-on Senior .NET Developer / Technical Lead role focused on building backend APIs for a new customer mobile app and modernizing a large operational platform. The role offers ownership of architecture, integrations, engineering standards, and future backend team development, with compensation of $5,000–$6,000 plus milestone bonuses and relocation support to Warsaw. 🗂️ Requirements: Commercial .NET / C# experience, Production backend systems and API development experience, API design, authentication, authorization, and security knowledge, SQL and database design experience, Third-party and existing business-system integration experience, Legacy application modernization experience, Cloud infrastructure, CI/CD, testing, and production support knowledge, Technical ownership and sound decision-making ability, Strong communication and practical problem-solving skills 📃 Skills: .NET, C#, API, SQL, Authentication, Authorization, Security, CI/CD, Cloud, Testing, Monitoring, Azure, Umbraco, Microservices, IoT, CRM, ERP, CMS 🏢 Description: One of the largest logistics and storage companies in the region is looking for a Senior .NET Developer / Technical Lead to help build the next generation of its technology platform. This is a hands-on role with significant ownership. You’ll work closely with leadership and product teams, make important technical decisions, and help modernize a large operational platform used across the business. Your first project Your immediate priority will be building the backend APIs for a new customer mobile application. Customers will use the app to manage their accounts and rentals, make payments, and access their storage units. You’ll work closely with the mobile team to design the APIs, authentication, permissions, integrations, and backend workflows that make this possible. Beyond the mobile application, you’ll help move the business away from legacy systems and towards a modern, API-driven platform connecting customer applications, operations, payments, access control, reporting, notifications, and other core services. What you’ll do • Design and build production APIs and backend services using .NET / C# • Work closely with the mobile team on API contracts and backend workflows • Take ownership of key backend and architecture decisions • Integrate new services with existing systems and SQL databases • Help modernize and gradually replace legacy applications • Design secure and reliable integrations between business-critical systems • Improve testing, monitoring, documentation, and CI/CD practices • Help establish development standards as the platform grows • Mentor and potentially help build the future backend team What we’re looking for • Strong commercial experience with .NET / C# • Proven experience building production backend systems and APIs • Strong understanding of API design, authentication, authorization, and security • Good SQL and database design experience • Experience integrating third-party or existing business systems • Experience working with or modernizing legacy applications • Understanding of cloud infrastructure, CI/CD, testing, and production support • Ability to take ownership and make sound technical decisions • Strong communication skills and a practical approach to solving problems Nice to have • Azure or another major cloud platform • Payments • Mobile application backends • Access-control, IoT, or hardware-connected systems • CRM, ERP, CMS, or operational platforms • Umbraco • Microservices or event-driven systems • Leading or mentoring other developers Why join? This isn’t a maintenance role. You’ll have the opportunity to influence the architecture of a major new platform, replace legacy technology with modern systems, and see the software you build used directly by customers and operations. You’ll join at an important stage of the project with the opportunity to take real technical ownership and grow into a broader leadership role as the engineering team expands. Offer • $5,000–$6,000, depending on experience • Rewarding bonuses for milestones hit • Work in a new high-tech office in Warsaw • Long-term growth opportunities and career progression • Relocation support to Warsaw, if needed

🏢 Summary: Oferta dla samodzielnego Mid .NET Developera do zdalnej, długoterminowej współpracy B2B przy utrzymaniu, rozwoju i optymalizacji istniejących aplikacji biznesowych klienta z USA. Rola obejmuje rozwiązywanie incydentów, refaktoryzację, optymalizację baz danych oraz bezpośrednią współpracę z biznesem, z naciskiem na stabilność i bezpieczeństwo. 🗂️ Requirements: 3–5 lat komercyjnego doświadczenia w .NET, Doświadczenie w pracy z relacyjnymi bazami danych, Bardzo dobra znajomość SQL i optymalizacji zapytań, Praktyczna znajomość ASP.NET Web API, Znajomość wzorców projektowych, Doświadczenie z Docker, GitHub Actions, Kafka, AWS i Terraform, Angielski na poziomie minimum B2+, Samodzielne priorytetyzowanie zadań, Dbałość o bezpieczeństwo wrażliwych danych, Umiejętność bezpośredniej komunikacji z biznesem 📃 Skills: .NET, C#, ASP.NET, SQL, SQLServer, PostgreSQL, Docker, GitHub, Kafka, AWS, Lambda, CDK, Terraform 🏢 Description: co.brick talents — powered by AI, powered by people. Mid .NET Developer Stawka: 110 – 120 PLN/h + VAT (B2B) Długość projektu: 12+ miesięcy (docelowo współpraca długofalowa) Forma pracy: 100% Remote Godziny pracy: Poniedziałek – Czwartek (06:00 – 16:00) LUB Poniedziałek – Piątek (06:00 – 14:00) Klient: Firma technologiczna z USA O roli i projekcie Szukamy doświadczonego i samodzielnego .NET  Developera (Mid) do zespołu pracującego bezpośrednio dla naszego klienta z USA. Rola polega na utrzymaniu, rozbudowie oraz optymalizacji istniejących systemów i aplikacji biznesowych. Nie jest to projekt typu greenfield — główny nacisk kładziemy na stabilność, utrzymanie wysokiej jakości kodu, refactoring oraz szybkie i skuteczne rozwiązywanie realnych problemów użytkowników. Szukamy osoby o podejściu customer-first , dla której priorytetem jest dostarczanie wartości biznesowej, dbając jednocześnie o bezpieczeństwo i ciągłość działania operacyjnego. Twoje zadania Utrzymanie, rozwój i optymalizacja istniejącego ekosystemu aplikacji klientów. Analiza błędów, rozwiązywanie incydentów oraz wdrażanie poprawek i nowych funkcjonalności. Pisanie wydajnych zapytań SQL oraz optymalizacja baz danych (SQL Server, PostgreSQL). Bliska współpraca i bezpośrednia komunikacja ze stakeholderami po stronie klienta. Dbanie o stabilność środowiska, minimalizowanie ryzyka operacyjnego i wprowadzanie dobrych praktyk architektonicznych. Wymagania Doświadczenie: Min. 3–5 lat komercyjnego doświadczenia w programowaniu .NET i pracy z bazami danych. Znajomość języka angielskiego: Poziom min. B2+ (płynna komunikacja ustna i pisemna w codziennej pracy z klientem z USA). Zaawansowany SQL: Bardzo dobra znajomość relational databases (SQL Server, PostgreSQL) oraz umiejętność optymalizacji zapytań. Technologie .NET: Praktyczna znajomość ASP.NET Web API oraz wzorców projektowych. Środowisko i narzędzia: Doświadczenie w pracy z Docker, GitHub Actions, Kafka, chmurą AWS (Lambda, CDK) oraz Terraform. Samodzielność i odpowiedzialność: Umiejętność priorytetyzacji zadań w dynamicznym środowisku oraz dbałość o szczegóły przy pracy z wrażliwymi danymi. Proaktywność i komunikatywność: Umiejętność budowania relacji i bezpośredniej dyskusji z biznesem. Stack technologiczny Language/Frameworks: .NET, ASP.NET Web API, C# Databases: SQL Server, PostgreSQL, Advanced SQL Cloud & DevOps: AWS (Lambda, CDK), Docker, GitHub Actions, Terraform Messaging: Kafka Architecture: Design Patterns

🏢 Summary: 6-miesięczny kontrakt z możliwością przedłużenia dla Senior .NET Developera odpowiedzialnego za projektowanie, rozwój i utrzymanie skalowalnych aplikacji backendowych oraz API. Rola obejmuje współpracę z zespołami projektowymi, projektowanie architektury, optymalizację rozwiązań, utrzymanie systemów produkcyjnych i wsparcie mniej doświadczonych osób. 🗂️ Requirements: Minimum 6 lat komercyjnego doświadczenia w C#/.NET, Bardzo dobra znajomość .NET Core / .NET 6+, Doświadczenie w projektowaniu i rozwoju aplikacji backendowych oraz REST API, Znajomość wzorców projektowych i zasad SOLID, Doświadczenie w pracy z bazami danych SQL, Znajomość Git i praktyk CI/CD, Doświadczenie w Agile, Scrum lub Kanban, Bardzo dobra znajomość języka angielskiego 📃 Skills: C#, .NET, SQL, REST, Git, CI/CD, Agile, Scrum, Kanban, SOLID 🏢 Description: Poszukujemy doświadczonego Senior .NET Developera (C#) do realizacji projektu dla naszego klienta. Jest to kontrakt na 6 miesięcy z możliwością przedłużenia współpracy. Zakres obowiązków Projektowanie, rozwój i utrzymanie aplikacji backendowych w technologii C#/.NET. Tworzenie oraz rozwijanie wydajnych i skalowalnych usług oraz API. Współpraca z zespołem projektowym przy analizie wymagań biznesowych i technicznych. Dbanie o wysoką jakość kodu poprzez stosowanie dobrych praktyk programistycznych oraz udział w code review. Identyfikowanie i rozwiązywanie problemów technicznych oraz optymalizacja istniejących rozwiązań. Tworzenie i aktualizacja dokumentacji technicznej. Udział w projektowaniu architektury aplikacji oraz proponowanie usprawnień technologicznych. Współpraca z zespołami QA, DevOps oraz analitykami w celu sprawnej realizacji projektu. Wsparcie mniej doświadczonych członków zespołu oraz dzielenie się wiedzą. Aktywny udział w procesie wdrażania nowych funkcjonalności i utrzymania systemów produkcyjnych. Wymagania: Minimum 6 lat doświadczenia komercyjnego w programowaniu w C#/.NET . Bardzo dobra znajomość platformy .NET (.NET Core / .NET 6+). Doświadczenie w projektowaniu i rozwoju aplikacji backendowych oraz REST API. Znajomość wzorców projektowych i zasad SOLID. Doświadczenie w pracy z bazami danych SQL. Znajomość Git oraz praktyk CI/CD. Umiejętność pracy w metodykach Agile (Scrum/Kanban). Bardzo dobra znajomość języka angielskiego umożliwiająca pracę w międzynarodowym środowisku.

🏢 Summary: Senior Fullstack .NET Developer role for a long-term, fully remote banking programme modernising and scaling cloud-based banking and securities platforms. The role focuses primarily on C#/.NET development, Azure migration, event-driven solutions and Angular front ends, with end-to-end delivery responsibility and occasional on-call support. Offers up to 180 PLN/h + VAT on B2B, UK working hours, and significant technical impact across an international organisation. 🗂️ Requirements: 7+ years of professional .NET development experience, Strong hands-on C# and modern .NET experience, Full-stack development experience, Commercial Angular or modern frontend framework experience, SOLID principles and software design expertise, Unit and integration testing experience, MongoDB or document-oriented database experience, Event-based messaging framework familiarity, Independent full development lifecycle delivery, Availability for occasional on-call shifts, Strong communication skills, Proactive, responsible approach 📃 Skills: C#, .NET, Angular, MongoDB, Azure, Murex, SOLID, Messaging, Queueing, Containers, Testing 🏢 Description: Rate : up to 180 PLN/h + VAT under a B2B contract 100% remote work Long-term cooperation within the banking sector UK working hours Significant technical impact across a large international organisation Opportunity to work with modern cloud, messaging and database technologies Start date: ASAP / flexible We are looking for an experienced Senior Fullstack .NET Developer to join an international banking programme focused on scaling cloud-based platforms and building a unified architecture for banking and securities operations. About the project The programme is focused on combining banking and securities operations within a common technology landscape. The UK architecture has been selected as the target model and is now being extended to support the wider organisation. The team is migrating applications to Azure, introducing containerised solutions and gradually moving away from traditional SQL-based systems towards MongoDB and document-oriented databases. You will work across a portfolio of approximately 17 internally developed applications supporting areas such as Product Control and Risk Management. Your responsibilities Developing and extending applications using C# and .NET (80% of workload) Building scalable systems capable of supporting additional business entities. Contributing to the migration of applications and business logic to Azure. Developing event-driven and message-based solutions. Working with Angular-based frontend applications. Designing solutions in line with SOLID principles and clean-code practices. Writing and maintaining unit and integration tests. Taking end-to-end responsibility for development, testing and implementation. Cooperating closely with Business Analysts and other project stakeholders. Supporting production applications and participating in occasional on-call shifts. Technology environment C# / .NET Angular MongoDB Event-driven architecture Messaging and queueing frameworks Azure Containerised applications Murex and internally developed platforms Unit and integration testing What we are looking for At least 7 years of professional .NET development experience. Strong hands-on experience with C# and modern .NET. Full-stack development experience. Commercial experience with Angular or another modern frontend framework. Very good understanding of SOLID principles and software design. Experience with unit and integration testing. Experience with MongoDB or other document-oriented databases. Familiarity with event-based messaging frameworks. Ability to work independently across the full development lifecycle. Strong communication skills and a proactive, responsible approach. On-call responsibility The position includes an occasional on-call element, typically around 1–2 shifts per month . Recruitment process The recruitment process consists of two stages: A technical coding assignment, estimated at approximately 2–4 hours. A technical interview focused on your solution, design decisions, testing approach and understanding of software engineering principles.

🏢 Summary: Remote B2B opportunity for a .NET Software Developer to design, build, and optimize mission-critical enterprise systems for a major European institution. The role includes end-to-end development, technical leadership, solution design, testing, release management, and advanced technical support, with occasional visits to Warsaw. 🗂️ Requirements: 4+ years of IT-relevant professional experience, 2+ years of relevant project or similar-role experience, 2+ years working with mission-critical complex enterprise systems, Experience with asset or human-resources management and financial-management systems, Expertise in enterprise-level .NET software development, Data, business-logic, and UI layer design and development experience, UML application design experience, Completion of at least one full software-solution lifecycle, Scrum development experience, Technical team leadership experience, Fluent English at B2 level or higher, Bachelor’s degree or equivalent 3 years of higher education in an ICT-relevant field, Intermediate .NET software-development certification or an accepted equivalent international certification 📃 Skills: .NET, UML, Scrum, ICT 🏢 Description: Software Developer (.NET) — own system design, lead technical teams, and drive end-to-end development. Far-site remote, 200 PLN net/h B2B. IT · Multiple locations · Fully Remote About the Client and our Role At Optiveum, we connect top IT professionals with exciting tech initiatives. In this case, we are the recruitment partner acting within the TimeDev Framework Agreement to provide outsourcing consultants for our partner organization . By taking part in this long-term project, you will be contributing as a Software Developer to support a major European institution. The Role We are looking for a Software Developer (.NET) to take an active role in designing, building, and optimizing enterprise-level software systems. In this position, you will lead development initiatives, implement robust solutions across data, business logic, and UI layers, and ensure software meets stringent security, performance, and quality standards. You will work closely with other technical teams to prototype solutions and support complex enterprise frameworks. Responsibilities Design and develop the system, translating requirements into technical design. Lead development teams and set software development standards. Design applications using UML and optimize software for performance, security, and quality. Propose technical solutions for business needs and solve complex technical problems. Estimate effort and time for development. Produce technical documentation and effectively document developments. Manage configuration, releases, and collect/interpret software metrics. Contribute to requirements analysis, testing, quality assurance, change management, and deployment. Test solutions, develop testing tools, and prototype new features. Act as 2nd and 3rd line technical support. Expectations Experience: Minimum 4 years of overall IT-relevant professional experience, including at least 2 years of project experience relevant to the profile (or in a similar position). Specific Domain Expertise: At least 2 years of experience with mission-critical complex enterprise systems, specifically including asset and/or human resources management, as well as financial management. Technology Stack: Expert in developing enterprise-level software systems in the .NET technology domain . Technical Skills: Proficient in designing and developing the data layer, business logic layer, and UI layer. Strong knowledge of UML and ability to design applications in UML. Completion of at least 1 full lifecycle of a software solution. Process & Leadership: Experience working in Scrum developments, capable of leading technical teams, and strong problem-solving skills. Language: Fluent English (minimum B2 level / CEFR). Education (Level 6): Minimum Bachelor’s degree (or 3 years of higher education confirmed by a diploma). An ICT-relevant degree is mandatory. Certifications Requirements You must possess at least one of the following: An Intermediate level certificate in software development relevant to the domain (.NET). An equivalent internationally recognized certification (subject to acceptance as a valid credential by the Contracting Authority). What We Offer Salary: max 200 net / hour. Contract Type: B2B agreement. Type of Work: Remote with occassional visits to the client HQ in Warsaw, Poland