Senior .NET Developer Blazor UI focus

Keystone Solutions; Brussel Hoofdstad; Híbrido; EUR 70.000 - 90.000; Tempo integral

Resumo da vaga

Keystone Solutions is seeking a Senior .NET Developer (Blazor, UI focus) on a consultant mission at a client site. You will lead UI architecture while delivering hands-on features using C#, Blazor, and modern .NET.

You will collaborate with analysts and UX, ensure accessibility, and integrate with REST APIs and secure authentication. Expect a dynamic, technically focused environment with knowledge sharing and architectural oversight.

Qualificações

• Agile/Scrum experience with practical application.
• Experience with Blazor and Razor components.
• Strong C# and .NET development skills.
• Experience with EF Core and SQL.
• Knowledge of REST APIs and JSON exchanges.
• Experience with secure auth (OAuth2 / OpenID Connect).
• Tests: unit, component, and UI automation.
• WCAG 2.1 AA accessibility knowledge.

Responsabilidades

• Provide technical UI leadership and enforce UI standards.
• Hands-on development with C#, Blazor, Razor components.
• Design scalable, maintainable front-end structures.
• Build responsive, accessible user interfaces across devices.
• Collaborate with analysts/UX to translate requirements.
• Integrate Blazor apps with REST APIs and secure auth flows.
• Maintain code quality via reviews and testing practices.
• Use Git and Azure DevOps for CI/CD pipelines.
• Coach other developers and share knowledge.
• Lead debugging across dev and prod environments.
• Evaluate technologies aligned with architecture and security decisions.

Conhecimentos

Agile / Scrum

AI-assisted development

Blazor and Razor components

C#

Entity Framework Core and SQL

HTML/CSS and responsive design

Modern .NET / ASP.NET Core

OAuth 2.0 / OpenID Connect / JWT

REST APIs and JSON exchanges

Testing (unit, UI, integration)

Web accessibility WCAG 2.1 AA

Ferramentas

Git

Azure DevOps

CI/CD pipelines

Descrição da vaga

Mission Overview:

Join Keystone Solutions as a Senior .NET Developer (Blazor, UI focus) on a consultancy mission at a client site. You will play a crucial role in building the future of public health technology, directly supporting digital services that enhance the health and wellbeing of millions. Your expertise will be essential in designing and delivering secure, accessible, and high-impact business applications, from the Blazor user interface to the .NET services behind it.

Key Responsibilities:

• Provide technical leadership for the user interface, promoting a consistent approach to UI architecture and coding standards.
• Dedicate significant time to hands‑on development of features, reusable components, and technical improvements using C#, modern .NET, Blazor, and Razor components.
• Design scalable and maintainable front‑end structures that align with architectural principles.
• Build responsive user interfaces that meet accessibility standards and ensure usability across devices.
• Collaborate with analysts and UX stakeholders to clarify requirements and translate them into robust technical solutions.
• Integrate Blazor applications with REST APIs and ensure secure authentication and authorization flows.
• Maintain high code quality through structured reviews and testing practices.
• Utilize Git and Azure DevOps for version control and CI/CD pipelines.
• Coach and share knowledge with other developers, fostering a culture of technical excellence.
• Lead troubleshooting efforts for complex issues across development and production environments.
• Evaluate and recommend relevant technologies that align with architectural and security decisions.

Key Technical Expertise:

• Advanced proficiency in C# and modern .NET development practices.
• Hands‑on experience with Blazor applications and component lifecycle management.
• Strong command of HTML, CSS, and responsive design.
• Practical experience with web accessibility standards (WCAG 2.1 level AA).
• Proven experience with REST APIs and JSON exchanges.
• Experience implementing secure authentication using OAuth 2.0 and OpenID Connect.
• Working proficiency with Entity Framework Core and SQL.
• Strong experience with unit testing and automated UI testing.
• Advanced use of Git and Azure DevOps.
• Knowledge of AI-assisted development practices.

Key Soft Skills:

• Technical leadership and mentorship abilities.
• Effective collaboration in a multidisciplinary environment.
• Strong problem‑solving and decision‑making skills.
• User‑focused approach to digital experiences.
• Clear communication of complex technical matters.
• Resilience and adaptability to changing technologies.
• Commitment to continuous improvement and professional development.

Duration: 23/11/2026 - 31/12/2026 2 months (full time)

Skills required:

• Agile / Scrum - Level: Confirmed - Most recent: Any time
• AI-assisted development (GitHub Copilot, Claude Code or similar) - Level: Junior - Most recent: Any time
• Blazor and Razor components, including Blazor Web App render modes - Level: Junior - Most recent: Any time
• C# - Level: Confirmed - Most recent: Any time
• Entity Framework Core and SQL - Level: Confirmed - Most recent: Any timeGit, Azure DevOps and CI/CD pipelines - Level: Confirmed - Most recent: Any time
• HTML, CSS and responsive design - Level: Confirmed - Most recent: Any time
• Modern .NET / ASP.NET Core - Level: Confirmed - Most recent: Any time
• OAuth 2.0 and OpenID Connect, JWT, claims-based authorisation - Level: Confirmed - Most recent: Any time
• REST APIs and JSON exchanges - Level: Confirmed - Most recent: Any time
• Testing: unit, component, integration and UI automation - Level: Confirmed - Most recent: Any time
• Web accessibility, WCAG 2.1 AA - Level: Junior - Most recent: Any time

Language requirements:

Dutch
Level Active knowledge
English
Level Active knowledge
French
Level Active knowledge