Senior Backend Developer

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

Ventajas ofrecidas por este puesto de trabajo

Valencia hub

Senior engineering team

Descripción de la vacante

Isg International Service Group seeks a Senior Backend Developer to join a new Generative AI hub in Valencia. You will shape technical foundations, architecture, and production-grade AI services for the financial sector.

You will work on backend APIs, data pipelines, vector search, and agent orchestration, using Node.js or .NET 8 on Azure. This is a founding engineer role in a high-impact, high-speed environment.

Formación

• 5+ years of backend development experience in production environments.
• Strong proficiency in Node.js OR .NET 8 / ASP.NET Core (or both).
• Hands-on experience with Azure cloud services: ADF, Cognitive Search, OpenAI, SQL, Cosmos DB.

Responsabilidades

• Design and build backend services and APIs powering the Generative AI platform.
• Implement data pipelines using Azure Data Factory and Document Intelligence.
• Develop vector indexing and semantic search with Azure Cognitive Search and LightRAG.
• Create embedding generation pipelines using Azure OpenAI.
• Manage multi-layer storage: Azure SQL, PostgreSQL, Cosmos DB, Blob Storage.
• Integrate agent tooling with Langchain, Langgraph, FastAPI, MCP.
• Coordinate orchestration with Mastra for multi-agent workflows.
• Ensure observability with Azure Monitor and Log Analytics.
• Evaluate LLM outputs with Azure ML and guardrails with Azure OpenAI.

Conocimientos

Node.js

.NET 8

Azure cloud

RESTful APIs

Microservices

Docker

Kubernetes

SQL

RBAC

CI/CD

English fluent

Herramientas

Azure Data Factory

Azure Cognitive Search

Azure OpenAI

Azure SQL

Cosmos DB

Langchain

Langgraph

FastAPI

MCP

Mastra

AKS

Azure Monitor

Azure Key Vault

Descripción del empleo

Descripción del trabajo

About the Role

Our client, a top IT consultancy, is partnering with a leading financial services organisation, to build a dedicated Generative AI hub in Valencia. This new unit will serve as the engine for organisations AI-driven transformation, designing and delivering intelligent solutions that modernise financial processes, automate decision-making, and unlock new value across the organisation.

We are looking for a Senior Backend Developer to be one of the founding engineers of this hub. You will help define the technical foundations of an Agentic AI platform built on Azure, contributing from day one to architecture decisions, infrastructure setup, and the delivery of production-grade AI-powered services for the financial sector.

Key Responsibilities

• Design and build the backend services and APIs that power the organisations Generative AI platform, using Node.js or .NET 8 (ASP.NET Core / EF Core)
• Implement data ingestion, chunking, cleaning and quality checks pipelines using Azure Data Factory and Azure Document Intelligence
• Build and maintain vector indexing and semantic search capabilities via Azure Cognitive Search and LightRAG
• Develop embedding generation pipelines using Azure OpenAI
• Design and manage multi-layer data storage: Azure SQL, PostgreSQL, Azure Cosmos DB (agent memory), Azure Blob Storage
• Build and integrate agent tooling using Langchain, Langgraph, FastAPI, A2A, AG-UI and MCP
• Implement the AIDA orchestration and coordination layer using Mastra (Multi-Agentic Orchestrator)
• Ensure platform observability and alerting via Azure Monitor and Azure Log Analytics
• Implement evaluation pipelines for LLM outputs using Azure ML
• Apply guardrails and output validation using Azure OpenAI and Azure Machine Learning
• Implement authentication and RBAC using Azure Active Directory
• Manage secrets and configuration securely via Azure Key Vault
• Contribute to the technical culture of the hub: code reviews, documentation, architecture decisions, and engineering best practices

Technology Stack

Backend Core

• Node.js or.NET 8 (ASP.NET Core, Entity Framework Core)
• RESTful API design ·Event-driven architectures

Azure Data & AI Services

• Azure Data Factory — ingestion, chunking, cleaning, DQ checks
• Azure Document Intelligence — document parsing and understanding
• Azure Cognitive Search — vector indexing and semantic search
• Azure OpenAI — LLM access, embedding generation, guardrails and output validation
• Azure Machine Learning — model evaluation and ML guardrails
• LightRAG — retrieval engine for RAG pipelines

Storage & Databases

• Azure SQL ·PostgreSQL — relational data and metadata storage
• Azure Cosmos DB — short-term and long-term agent memory
• Azure Blob Storage — file and document storage

Agent Infrastructure

• Langchain & Langgraph — agent orchestration and chaining
• FastAPI — lightweight API layer for agent tooling
• A2A, AG-UI, MCP — agent-to-agent communication and UI protocols
• Mastra — Multi-Agentic Orchestrator (non-Azure, self-hosted)

Platform & DevOps

• Azure Kubernetes Service (AKS) — agent runtime hosting
• Azure Active Directory — authentication & RBAC
• Azure Key Vault — secrets and keys management
• Azure Monitor · Azure Log Analytics — observability
• Azure App Service · Azure Static Web Apps — UI/UX deployment

Required Skills & Experience

• 5+ years of backend development experience in production environments
• Strong proficiency in Node.js OR .NET 8 / ASP.NET Core (or both)
• Solid hands-on experience with Azure cloud services: ADF, Cognitive Search, OpenAI, SQL, Cosmos DB
• Experience building RESTful APIs and microservices in regulated or high-availability environments
• Familiarity with vector databases, embeddings and RAG-based architectures
• Understanding of Agentic AI patterns: multi-agent systems, tool use, orchestration, memory layers
• Experience with containerisation (Docker / Kubernetes / AKS)
• Proficiency in SQL (Azure SQL, PostgreSQL)
• Strong understanding of security best practices: authentication, RBAC, secrets management
• Experience with CI/CD pipelines and DevOps practices on Azure
• Ability to work autonomously in a greenfield, fast-paced environment
• Fluent English — working language for all technical documentation and ceremonies
• Location - preferably Valencia, but open to other locations with availability to travel occasionally to Valencia; remote in that case.

Nice to Have

• Experience with Python / FastAPI for agent tooling layers
• Knowledge of Langchain, Langgraph or similar LLM orchestration frameworks
• Familiarity with MCP (Model Context Protocol), A2A or AG-UI protocols
• Prior experience in a hub or centre-of-excellence environment
• Background in financial services, banking or fintech
• GitHub certification
• Spanish language skills

Why Join This Team

• Founding engineer role — shape the architecture and culture of a brand-new GenAI hub from day one
• Work at the cutting edge of Agentic AI applied to real financial services use cases
• Backed by the organisations global engineering community, tooling and career development programmes
• Valencia-based hub with a collaborative, senior-weighted team
• Direct exposure to the companys transformation agenda and senior stakeholders