Senior Frontend Developer

ISG International Service Group; Valencia; Híbrido; EUR 70.000 - 100.000; Jornada completa

Descripción de la vacante

ISG International Service Group is seeking a Senior Frontend Developer to help establish a Valencia-based Generative AI hub. You will own the user-facing layer of IMF’s Agentic AI platform, building React applications that render real-time LLM outputs and provide intuitive interfaces for financial workflows.

You will design reusable component libraries, implement streaming interfaces, and integrate with Azure services, RBAC, and deployment pipelines.

Formación

• 5+ years of frontend development in production environments.
• Expert-level React and TypeScript with performance optimisation.
• Experience building and consuming RESTful APIs, including streaming data.
• Solid knowledge of state management: React Query, Zustand or Redux Toolkit.
• Experience with Azure services (App Service, Static Web Apps, Active Directory).
• Fluent English; open to Valencia location with remote travel.

Responsabilidades

• Design and build production-grade React applications for the Generative AI platform.
• Develop reusable UI component libraries in React and TypeScript.
• Implement real-time agent interfaces and streaming LLM outputs.
• Integrate frontend with RESTful and event-driven backends (Node.js / .NET 8 / FastAPI).
• Visualise AI-generated outputs and agent reasoning traces in UI.
• Implement authentication and RBAC flows using Azure AD / MSAL.
• Collaborate with UX, backend engineers, and AI/ML specialists.
• Maintain Storybook docs and frontend coding standards.
• Contribute to Valencia hub engineering culture from day one.

Conocimientos

React & TS

Azure services

REST APIs streaming

State management

Testing (Jest/RTL)

OAuth/MSAL

English fluency

UI architecture

Herramientas

Next.js

Storybook

Docker

Jest

Playwright

Azure App Service

Azure Static Web Apps

Descripción del empleo

Our client, a top IT consultancy, is partnering with a leading financial services organisation, to establish a dedicated Generative AI hub in Valencia. This new unit will be the centre of the financial services provider's AI-driven transformation — building intelligent applications that modernise financial workflows, surface AI-generated insights, and deliver seamless digital experiences to advisors and end users.

We are looking for a Senior Frontend Developer to be one of the founding engineers of this hub. You will own the user-facing layer of IMF’s Agentic AI platform: building React applications that interact with LLM agents in real time, rendering structured AI outputs, and creating interfaces that make complex financial AI capabilities accessible and intuitive for users.

Key Responsibilities

• Design and build production-grade React applications for the organisation's Generative AI platform, including agent-facing dashboards, document intelligence interfaces, and advisor-facing portals
• Develop reusable, accessible, and well-tested UI component libraries in React and TypeScript
• Implement real-time agent interaction interfaces using AG-UI and A2A protocols, including streaming LLM output rendering
• Integrate frontend applications with RESTful and event-driven backend APIs (Node.js / .NET 8 / FastAPI)
• Consume and visualise AI-generated outputs: RAG responses, document analysis results, agent reasoning traces, and evaluation metrics
• Implement authentication and RBAC flows using Azure Active Directory / MSAL
• Connect applications to Azure App Service and Azure Static Web Apps deployment pipelines
• Build frontend observability integrations with Azure Monitor and Application Insights
• Collaborate with UX, backend engineers, and AI/ML specialists to translate complex agent behaviours into clear, usable interfaces
• Maintain component documentation (Storybook) and uphold frontend coding standards
• Contribute to the technical culture and engineering practices of the Valencia hub from day one

Frontend Core

• React 18+ ·TypeScript — primary UI framework and language
• Next.js or Vite — application bundling and server-side rendering
• React Query / Zustand / Redux Toolkit — state and data management
• Tailwind CSS / CSS Modules — styling
• Storybook — component documentation and design system
• Jest ·React Testing Library · Playwright — unit, integration and E2E testing

Agent & AI Interface Layer

• AG-UI protocol — agent-to-UI streaming and real-time interaction interfaces
• A2A (Agent-to-Agent) — inter-agent communication surfaced at the UI layer
• MCP (Model Context Protocol) — context and tool-call integration in the frontend
• Azure OpenAI response streaming — real-time LLM output rendering and progressive disclosure
• Azure App Service · Azure Static Web Apps — hosting and deployment
• Azure Monitor · Application Insights — frontend observability and error tracking
• Azure Key Vault — secure handling of client-side secrets and configuration
• Azure Kubernetes Service (AKS) — understanding of the agent runtime environment
• REST APIs served by Node.js or .NET 8 (ASP.NET Core) — primary integration surface
• FastAPI endpoints — agent tooling and LLM-facing APIs
• Azure Cosmos DB — agent short-term / long-term memory surfaced in UI
• Azure Cognitive Search — vector search and RAG results rendered in UI components

DevOps & Tooling

• Git ·GitHub / Azure DevOps — version control and CI/CD
• Docker — local development and containerised builds
• ESLint ·Prettier · Husky — code quality and pre-commit hooks

Required Skills & Experience

• 5+ years of frontend development experience in production environments
• Expert-level React and TypeScript — hooks, context, performance optimisation, custom component libraries
• Experience building and consuming RESTful APIs, including streaming and real-time data
• Solid knowledge of state management patterns (React Query, Zustand or Redux Toolkit)
• Experience with Azure platform services — especially App Service, Static Web Apps, Active Directory
• Familiarity with authentication flows: OAuth 2.0, OpenID Connect, MSAL
• Experience with automated testing: unit (Jest / RTL) and E2E (Playwright or Cypress)
• Ability to work autonomously in a greenfield, fast-paced environment with shifting requirements
• Fluent English — working language for all technical documentation and ceremonies
• Location - preferably Valencia, but open to other locations with availability to travel to Valencia on a regular basis. In that case, remote.

Nice to Have

• Experience integrating with LLM streaming APIs (Azure OpenAI, OpenAI, Anthropic)
• Knowledge of AG-UI, A2A or MCP protocols for agent-facing user interfaces
• Familiarity with Next.js App Router / Server Components
• Experience with design systems and Storybook in large codebases
• Understanding of RAG pipelines and how to surface vector search results effectively in the UI
• Prior experience in a hub or centre-of-excellence environment
• Background in financial services, banking or fintech

Why Join This Team

• Founding engineer role — shape the UI architecture and design culture of a brand-new GenAI hub
• Work at the intersection of React and Agentic AI — a genuinely rare combination in the market
• Backed by the organisation's global engineering community, tooling and career development programmes
• Valencia-based hub with a collaborative, senior-weighted team
• Direct exposure to the company's transformation agenda and senior stakeholders