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Santiago VacasSV

Santiago Vacas

Supermalter

Senior Software Engineer · Cloud & AI Solutions

€360/day
5 projects
Almería, ES
8-15 years

Average response time: 1 hour

Freelancer profile translated to English.
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About Santiago

Senior Full Stack Engineer | Applied AI and Process Automation | Cloud & DevOps

  • I design and build solutions that integrate AI and automation into real business processes: fewer manual tasks, more efficient processes, and faster decisions. Over 9 years delivering stable, scalable, and maintainable products in technology, energy, health, retail, industry, education, and public administration.
  • My value is not just writing code: I lead the project from start to finish, from understanding the need of a non-technical business user to getting it running in production.

What I do

  • Applied AI and agents: RAG architectures, agentic workflows, and LLM integration into business processes (LangChain, LangGraph, OpenAI). Conversational and voice agents (ElevenLabs), custom MCP servers in Python, and large-scale OCR and document processing pipelines.
  • Automation and integration: Orchestration with n8n and Make, API integrations (REST/SOAP), webhooks, payment gateways, and data synchronization between disparate systems.
  • Full stack and mobile: React, Next.js, Angular (v8–v19) and Tailwind; Node.js (NestJS, Express), Python (FastAPI, Django), and PHP (Laravel); multi-tenant SaaS and apps published on the App Store and Google Play. PostgreSQL, MySQL, MongoDB, Redis.
  • Data: Data pipelines, ELT, and analytical modeling with Snowflake, Databricks, and dbt.
  • Cloud & DevOps: Deployment on AWS and Azure, Docker, Kubernetes, Terraform (IaC), CI/CD with GitHub Actions.
  • Security: OAuth2, JWT, Keycloak, and cybersecurity best practices.

How I work

  • Global technical vision, architectural clarity, and results orientation. I move with ease in corporate environments with multiple stakeholders, propose solutions with my own judgment, and lead initiatives from start to finish with little supervision. My goal: to turn a business need into an intelligent and automated solution that generates real and measurable impact.
  • Spanish

    Native or bilingual

Remote only
Primarily works remotely

Experience

  • Alfanar Energía España SLU.
    Malt logoOn Malt
    Project Summary – HRMODULE (Alfanar Energía España SLU)
    ENERGY AND UTILITIES
    March 2026 - May 2026 (2 months)
    Working on this project has been a very positive and technically interesting experience. During development, multiple backend and frontend challenges were successfully resolved within an architecture based on Python/Django (DRF), React, Docker, and Azure.

    Complex integrations with external APIs and Web Services were implemented, including connection with the payroll API for obtaining company cost through a custom authentication flow, as well as the creation of an intermediate layer in Django for bidirectional timesheet synchronization with external time tracking systems.

    Additionally, new full-stack functionalities were developed such as an advanced and interactive matrix organizational chart, adapted to non-hierarchical business structures, along with new PDF report generation templates integrated into the existing architecture.

    On the frontend, user experience was significantly improved through dynamic tables with advanced sorting optimized for performance and pagination, in addition to refactoring and standardization tasks to leave a cleaner, more maintainable, and scalable codebase.

    Communication throughout the project was excellent, allowing for fluid collaboration and rapid resolution of the various technical challenges that arose.
    Python Docker External API Integration Backend Service Development Database Management
  • Minsait (Grupo Indra), vía Malt
    AI Architect — RAG Architectures and Agentic Systems
    March 2026 - Today (5 months)
    Consulting as a freelance AI Architect on generative AI projects in a corporate environment. Design and implementation of RAG (Retrieval-Augmented Generation) architectures, agentic workflows, and LLM integration into business processes.
    Technical work: developing pipelines with LangChain and LangGraph, designing agentic workflows, integrating language models, and optimizing cost/performance in agent and RAG architectures. Developing an application with React (frontend), Python (backend), and PostgreSQL as the database. Collaboration in a corporate environment with multiple technical and business stakeholders.
    Stack: Python, React, PostgreSQL, Docker, LangChain, LangGraph, RAG architectures, LLM integration, agentic workflows.
  • Top Doctors
    Development of an AI Voice Agent for Call Reception and Appointment Management
    March 2026 - June 2026 (3 months)
    Design and development of an AI conversational voice agent to automate call reception and appointment management for a medical scheduling platform. The agent handles calls autonomously 24/7: it understands the user's request, checks real-time availability against the client's scheduling system (Ofimedic), and confirms the appointment immediately, without receptionist intervention.
    Technical work: custom development of an MCP server in Python that connects the agent (ElevenLabs) with the client's existing system via its API (SOAP/REST), managing availability and appointment synchronization, and optimizing the timing between the model's response and audio playback to achieve a natural and fluid conversation. Result: elimination of lost calls during peak hours and complete automation of a process that previously required constant human attention.
    Stack: Python, MCP (custom server), ElevenLabs, SOAP/REST APIs, Ofimedic integration.
    Python AI Agent External API Integration Backend Service Development Software Architecture

Reviews

5.0

Out of 5 ratings

L

Larry

System Development Engineer - Alfanar Energía España SLU.

Reviewed on 5/7/2026

Excellent work! Santiago met all deadlines and exceeded my expectations regarding the quality of the deliverables. Very professional and detail-oriented. Highly recommended!
D

David

Director - Onezix S.L

Reviewed on 2/27/2026

We continue to work with Santiago, and the experience is excellent. He stands out for his high proactivity, his ability to propose improvements and new modules with technical judgment and product vision. Communication is fluid and constant, he meets agreed deadlines, and the quality of the delivered code is very high. He is a reliable, problem-solving professional with great involvement in the project. Totally recommended.

Recommendations

IR
Broadway HouseBH
DP
+4
Ismael Renard and 6 other people have recommended Santiago

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Education

  • Azure DevOps
    Udemy
    2021
    Certificación orientada a la gestión completa del ciclo de vida del desarrollo mediante Azure DevOps, abarcando control de versiones, integración y despliegue continuo (CI/CD), automatización de pipelines, gestión de proyectos Agile y administración de entornos cloud. El curso proporciona las bases prácticas para implementar metodologías DevOps en Azure, optimizando la colaboración entre desarrollo, operaciones y entrega continua de software.
  • Microcomputer and Network Systems
    Francisco Javier de Burgos
    2015
    Formación técnica orientada a la instalación, configuración y mantenimiento de sistemas informáticos, redes locales y servicios básicos de infraestructura TI. Incluye competencias en hardware, software, seguridad, administración de sistemas operativos, redes LAN/WAN y soporte técnico, asegurando el correcto funcionamiento y la conectividad de entornos empresariales.

Skill set

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