Fullstack IA Developer (.NET/ React)

Responsibilities
Design and build the validation interface in React and TypeScript: document upload, tender classification review, budget comparison views and deviation dashboards.
Implement data-dense views presenting budget line items and statistical baselines (mean, median, deviation by work type, size and location), with drill-down from summary to individual line item.
Build the human-in-the-loop approval workflow: review, annotate, override and approve AI-generated results, with full traceability of who changed what and why.
Surface AI provenance in the interface — show the source document and passage supporting each generated figure so users can verify output rather than trust it blindly.
Implement responsive, accessible UI consistent with client branding; deliver interfaces in Spanish with an internationalisation-ready structure.
Handle streaming responses and long-running agent executions with appropriate progress, cancellation and error states.
Build and maintain backend services and REST APIs in .NET / C# that mediate between the front end and the AI orchestration layer.
Implement authentication and authorisation, including role-based access control appropriate to confidential supplier pricing data.
Develop data access and business services against PostgreSQL, and integrate with object storage for source documents.
Integrate with the agent and MCP layer developed by the Senior AI Engineer, including asynchronous job handling and result persistence.
Containerise front-end and backend services so they deploy unchanged to cloud, DXC platform or client on-premise infrastructure.
Contribute to CI/CD pipelines, automated testing (unit, integration, end-to-end) and code review.
Participate in client demonstrations and gather usability feedback from the teams who will use the tool daily.
Produce user-facing documentation and support end-user onboarding during pilot and production rollout.
Skills
Must have
5+ years of professional full stack development experience delivering production web applications.
Strong React and TypeScript: modern hooks patterns, state management, component architecture and performance optimisation.
Proven experience with data-dense interfaces: complex tables, filtering, sorting, drill-down navigation and data visualisation (AG Grid, TanStack Table, Recharts, D3 or equivalent).
Backend development in .NET / C#: ASP.NET Core, REST API design, Entity Framework Core, dependency injection and asynchronous programming.
Relational database skills: SQL, schema design and query optimisation. PostgreSQL preferred.
REST API integration, including asynchronous and long-running operations, streaming responses and robust error handling.
Docker and container-based delivery; ability to build applications that deploy to cloud or on-premise environments without provider-specific rework. Mandatory given the open deployment decision.
Authentication and authorisation: OAuth2/OIDC, JWT, role-based access control. Microsoft Entra ID experience valued.
Git-based workflows, code review discipline and CI/CD familiarity.
Automated testing across front-end and backend (Jest, Vitest, Playwright or Cypress; xUnit or NUnit).
Spanish C1/Native and English B2 or above. (technical reading)
Nice to have
Experience building interfaces for AI or LLM-powered applications: chat and streaming UIs, citation and source display, confidence indicators, feedback capture.
Azure platform experience: App Service, Container Apps, AKS, Blob Storage, Key Vault, Entra ID.
Kubernetes and Helm for portable deployment across cloud and on-premise targets.
UX sensibility for analytical and decision-support tools; ability to prototype and iterate with end users.
Accessibility standards (WCAG) and internationalisation frameworks (i18next or equivalent).
Python familiarity, sufficient to read and integrate with the AI services built by the Senior AI Engineer.
Reporting and export capability: PDF and Excel generation for budget and deviation reports.
Domain exposure to procurement, tendering, construction cost control, ERP or utilities systems.
Certifications: Microsoft Certified Azure Developer Associate (AZ-204) or equivalent.

Work arrangement
Yes