Senior Backend Developer

ISG International Service Group; Valencia; Híbrido; EUR 60.000 - 90.000; Jornada completa

Descripción de la vacante

ISG International Service Group is building a pioneering Generative AI hub in Valencia. You will be among the founding backend engineers, shaping the architecture and infrastructure for an AI-powered platform that redefines financial processes with secure data pipelines and scalable services.

You will implement RESTful microservices, data ingestion, vector search, and multi-agent orchestration while collaborating with a senior, globally distributed engineering team.

Formación

• 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.

Responsabilidades

• Design and build the backend services and APIs that power the Generative AI platform using Node.js or .NET 8.
• 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 via Azure Cognitive Search and LightRAG.
• Create agent tooling using Langchain, Langgraph, FastAPI, A2A, AG-UI and MCP.
• Implement the AIDA orchestration and coordination layer using Mastra.
• Ensure 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 ML.
• Manage secrets and configuration securely via Azure Key Vault.
• Contribute to engineering culture: code reviews, docs, architecture decisions and best practices.

Conocimientos

Backend development

Node.js

.NET 8

Azure cloud

REST APIs

Microservices

AI platform

English fluency

Autonomy

Herramientas

Azure Data Factory

Azure Cognitive Search

Azure OpenAI

Azure Machine Learning

Cosmos DB

Azure SQL / PostgreSQL

Docker / Kubernetes

Langchain / FastAPI

Descripción del empleo

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 organisation's 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 organisation's 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
• 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
• 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
• Node.js or.NET 8 (ASP.NET Core, Entity Framework Core)
• 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

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

Platform & DevOps

• Azure Key Vault — secrets and keys management

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

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 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