.NET Developer

🏢 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

🏢 Summary: Remote, long-term B2B contract for an experienced .NET Software Developer supporting a European Union organization. The role covers enterprise-system design and development, technical leadership, solution architecture, quality optimization, releases, testing, and 2nd/3rd-line support. Rate: 215 PLN net + VAT per hour. 🗂️ Requirements: Completed at least one full solution lifecycle, Expertise in enterprise-level software development, UML application design, Data, business-logic and UI-layer design and development, Scrum experience, Technical team leadership capability, Technical-solution documentation skills, Problem-solving skills, At least 2 years of experience with mission-critical complex enterprise systems, Experience with asset and/or human-resources management and financial-management systems, At least one internationally recognized intermediate software-development certification relevant to the domain 📃 Skills: .NET, UML, Scrum, Enterprise, Testing, Prototyping, Configuration, Deployment 🏢 Description: Currently, for one of our Partners, we are looking for an experienced Software Developer .NET (m/f/n) to support a long‑term project delivered for an organization of the European Union based in Warsaw. Requirements: Has gone at least 1 time through the complete lifecycle of the solution Expert in developing enterprise level software systems in specified technology domain Knows UML and can design applications in UML Proficient in designing and developing: data layer, business logic layer and UI layer Worked in Scrum developments Is capable for leading technical teams Holds ability to document effectively technical solutions Presents problem solving skills Specific requirements At least 2 years of experience with mission critical complex enterprise systems including asset and/or human resources management, as well as financial management. At least 1 certification among: Intermediate level certificate in software development relevant to the domain or an equivalent certification recognized internationally (subject to acceptance as a valid credential by the Contracting Authority) Typical tasks and responsibilities Designs and develops the system Lead development teams Translates requirements into design Optimizes software from performance, security and quality points of view Produces technical documentation Estimates effort and time for development Sets software development standards Propose technical solutions for business needs and technical problems Collects and interprets software metrics Manages configuration and releases Contributes to requirements analysis, testing, quality assurance, change management, deployment Tests solutions and develops testing tools Documents developments Prototypes solutions Acts as 2nd and 3rd line support Offer: Rate: 215 PLN net +VAT/H Set-up: Remote B2B

🏢 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 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: B2B .NET Developer role with hybrid work in Wroclaw or Krakow, delivering modern solutions across multiple industries. The role focuses on building maintainable .NET and Azure applications, CI/CD, AI solutions, client collaboration, and Agile delivery. 🗂️ Requirements: 3+ years of .NET web development experience, Experience with Microsoft Azure services, Experience with Azure DevOps or GitHub Actions, Basic Python exposure, Clean code, design patterns and modern architecture knowledge, English proficiency at B2 level 📃 Skills: .NET, Azure, AzureDevOps, GitHubActions, Python, CICD, Agile, DesignPatterns 🏢 Description: We’re looking for specialists open to cooperate on B2B basis, for our customer – Avanade Poland. Avanade website ; Privacy policy This role is available for specialists open to work in hybrid mode (offices in Wroclaw and Krakow) - we can discuss the frequency of visiting the office. Position: As .NET Developer, you will broaden your experience by working in modern projects for various domains and industries. You will extend your skills in a wide range of tools, focusing on tasks such as: Consistently developing and delivering high-quality, low-defect, maintainable and robust code using modern Microsoft technologies like .NET and Azure Working with CI/CD tools such as Azure DevOps/GitHub Actions Designing, prototyping and building AI solutions using Python , Azure and newest AI technologies Working directly with clients (both technical and business) to define and refine requirements Working closely with your project team using Agile methodologies Ensuring quality through adherence to technical best practice and through mentorship and feedback Working in projects for various industries: Energy, Automotive, Retail, Aviation, Finances, Health, Life Sciences and more. Required skills: For this role, you will need: 3y+ of experience with web development using .NET (.NET 10 is a nice-to-have) Experience with MS Azure and its services Azure DevOps or GitHub Actions At least basic exposure to Python Knowledge of clean code principles, design patterns and modern architecture English skills at B2 level (we communicate in English on a daily basis) Nice to have: Experience in AI-related projects (commercial or non-commercial) Fluency in using assistive development tools (e.g. GitHub Copilot, Cursor, Claude Code) Experience in Microsoft Foundry or Copilot Studio Working experience with Docker Knowledge of Front-End technologies (e.g. React.js) If you want to ask any questions before applying, feel free to reach out via LinkedIn !

🏢 Summary: Senior Fullstack Developer role focused on building and evolving secure, scalable products for offshore wind farm asset lifecycle management. The position combines .NET, Angular, AWS cloud-native development, distributed integrations, and production ownership, with technical leadership and mentoring responsibilities. 🗂️ Requirements: 5+ years of .NET Core, C#, and Angular experience, System integration and distributed application development experience, REST API, microservices, messaging, and SQL/NoSQL database expertise, AWS cloud-native engineering and production deployment experience, DevOps, CI/CD, test automation, and release management experience, Git, build/deployment tooling, Docker, and Kubernetes proficiency, Senior-level technical ownership, problem-solving, stakeholder communication, and mentoring ability 📃 Skills: .NET, C#, Angular, REST, Microservices, Docker, Kubernetes, Kafka, AMQ, SQL, NoSQL, AWS, EKS, Git, AzureDevOps, GitHubActions, DevOps, CI/CD 🏢 Description: For our client operating in the renewable energy industry , we are looking for a Fullstack Developer (.NET/Angular) to work on the continued development of a product suite supporting offshore wind farm asset lifecycle management. This role involves designing, developing, and evolving scalable, secure, and maintainable products using .NET technologies, Angular, cloud platforms, and modern integration frameworks. Location Hybrid - 2 days/week from Warsaw office Tasks Designing, developing, and evolving scalable, secure, and maintainable products using .NET technologies, Angular, cloud platforms, and modern integration frameworks Taking senior-level ownership of solution quality, security, and compliance by applying best practices for data protection, authentication, authorization, secure coding, observability, and regulatory requirements Owning and improving applications in production, including reliability, performance, maintainability, incident resolution, and continuous improvement of operational practices Driving cloud-native engineering practices, including deploying, scaling, and managing applications in AWS and designing resilient integrations using messaging systems such as Kafka Guiding technical discussions, supporting code reviews, mentoring less experienced engineers, and collaborating with architects, product owners, and stakeholders to translate business needs into robust technical solutions Requirements 5+ years of experience in .NET Core , C# , and Angular Strong experience with system integration and distributed application development using REST APIs , microservices , Docker , Kubernetes , messaging platforms such as Kafka or AMQ , and SQL or NoSQL databases Strong experience with cloud-native technologies on AWS , such as Kubernetes (EKS) , cloud storage, secrets management ( AWS Secrets Manager ), data pipelines, infrastructure automation, monitoring, and production-grade deployments Experience in DevOps practices and tools for automation, continuous integration, continuous delivery, test automation, release management, and improving developer productivity Confidence working with version control systems such as Git , build and deployment tools such as Azure DevOps or GitHub Actions , and containerization technologies such as Docker and Kubernetes Demonstrated senior-level ownership, strong problem-solving skills, and the ability to mentor colleagues, influence technical direction, communicate effectively with stakeholders, and balance delivery speed with long-term quality We Offer Ongoing support from a dedicated agent , taking care of your project continuity, client contact, necessary formalities, work comfort and development, Consultant Development Program – advice on growth planning based on the latest trends and market needs in IT, including consultations with agents and growth mentors, Access to 7N Learning & Development – a development and educational platform with webinars, a library of articles and industry reports, and regular invitations to one-time and recurring development events – technical, business, and lifestyle, Spectacular integration events , both for you (e.g., annual Kick-Off trip , Christmas parties, or Summer Olympics sports events) and for your loved ones (e.g., family picnics, movie premieres), Professional development not only during the project – you can get involved in knowledge transfer to others within the 7N Services offering directed at 7N clients, Relationships and access to the knowledge of the most experienced IT experts in the market – the average professional tenure of our consultants in Poland is over 10 years, A complete benefits package , including funding for medical care, life insurance, sports cards for you and your loved ones, as well as discounts in stores in Poland and abroad. About 7N Constantly searching for projects, difficult rate negotiations, lack of development support – sound familiar? At 7N, you gain not only stability of contracts but also the personal involvement of a dedicated agent who ensures your professional comfort and continuous access to development initiatives.

🏢 Summary: Hybrid Fullstack Developer role focused on developing and operating a product suite for offshore wind farm asset lifecycle management. The position involves building secure, scalable cloud-native applications with .NET, Angular, AWS, and distributed integration technologies while providing senior technical leadership. 🗂️ Requirements: 5+ years of experience with .NET Core, C#, and Angular, System integration and distributed application development experience, REST APIs, microservices, Docker, Kubernetes, Kafka or AMQ, and SQL or NoSQL database experience, AWS cloud-native engineering experience, including EKS, storage, secrets management, data pipelines, automation, monitoring, and production deployments, DevOps experience with CI/CD, test automation, release management, and automation, Git and Azure DevOps or GitHub Actions experience, Senior-level technical ownership and mentoring experience 📃 Skills: .NET, C#, Angular, AWS, EKS, REST, Microservices, Docker, Kubernetes, Kafka, AMQ, SQL, NoSQL, Git, AzureDevOps, GitHubActions, DevOps 🏢 Description: For our client operating in the renewable energy industry , we are looking for a Fullstack Developer (.NET/Angular) to work on the continued development of a product suite supporting offshore wind farm asset lifecycle management. This role involves designing, developing, and evolving scalable, secure, and maintainable products using .NET technologies, Angular, cloud platforms, and modern integration frameworks. Location Hybrid - 2 days/week from Warsaw office Tasks Designing, developing, and evolving scalable, secure, and maintainable products using .NET technologies, Angular, cloud platforms, and modern integration frameworks Taking senior-level ownership of solution quality, security, and compliance by applying best practices for data protection, authentication, authorization, secure coding, observability, and regulatory requirements Owning and improving applications in production, including reliability, performance, maintainability, incident resolution, and continuous improvement of operational practices Driving cloud-native engineering practices, including deploying, scaling, and managing applications in AWS and designing resilient integrations using messaging systems such as Kafka Guiding technical discussions, supporting code reviews, mentoring less experienced engineers, and collaborating with architects, product owners, and stakeholders to translate business needs into robust technical solutions Requirements 5+ years of experience in .NET Core , C# , and Angular Strong experience with system integration and distributed application development using REST APIs , microservices , Docker , Kubernetes , messaging platforms such as Kafka or AMQ , and SQL or NoSQL databases Strong experience with cloud-native technologies on AWS , such as Kubernetes (EKS) , cloud storage, secrets management ( AWS Secrets Manager ), data pipelines, infrastructure automation, monitoring, and production-grade deployments Experience in DevOps practices and tools for automation, continuous integration, continuous delivery, test automation, release management, and improving developer productivity Confidence working with version control systems such as Git , build and deployment tools such as Azure DevOps or GitHub Actions , and containerization technologies such as Docker and Kubernetes Demonstrated senior-level ownership, strong problem-solving skills, and the ability to mentor colleagues, influence technical direction, communicate effectively with stakeholders, and balance delivery speed with long-term quality We Offer Ongoing support from a dedicated agent , taking care of your project continuity, client contact, necessary formalities, work comfort and development, Consultant Development Program – advice on growth planning based on the latest trends and market needs in IT, including consultations with agents and growth mentors, Access to 7N Learning & Development – a development and educational platform with webinars, a library of articles and industry reports, and regular invitations to one-time and recurring development events – technical, business, and lifestyle, Spectacular integration events , both for you (e.g., annual Kick-Off trip , Christmas parties, or Summer Olympics sports events) and for your loved ones (e.g., family picnics, movie premieres), Professional development not only during the project – you can get involved in knowledge transfer to others within the 7N Services offering directed at 7N clients, Relationships and access to the knowledge of the most experienced IT experts in the market – the average professional tenure of our consultants in Poland is over 10 years, A complete benefits package , including funding for medical care, life insurance, sports cards for you and your loved ones, as well as discounts in stores in Poland and abroad. About 7N Constantly searching for projects, difficult rate negotiations, lack of development support – sound familiar? At 7N, you gain not only stability of contracts but also the personal involvement of a dedicated agent who ensures your professional comfort and continuous access to development initiatives.

🏢 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