Hello, I'm

Nicolas Guevara (Tostti)

GenAI Engineer | Full-stack developer

From models to systems that actually work.

About

GenAI engineer with a senior full-stack background. Focused on building RAG systems, LLM-integrated architectures, and production-ready applications. Studies how models behave, where they fail, and how to make them reliable and secure. Treats AI as an engineering discipline, where outcomes depend on solid implementation and informed human judgment.

Experience

  1. Avenga

    Córdoba, AR

    1. Senior Software Engineer

      Now

      Sep 2025 – Present

      Working full-time for a customer in the banking industry, developing the DS library for a new product and implementing AI features and reusable agent skills for the team.

      • React
      • TypeScript
      • Claude
  2. Wazuh Inc.

    Remote

    1. Staff Software Engineer

      Jan 2024 – Sep 2025

      Led a team of 3 developers responsible for the development and maintenance of the Wazuh Dashboard, the web interface of the Wazuh platform. Managed the team, designed and developed new features, fixed bugs, worked on package generation workflows, and supported community users.

      • TypeScript
      • JavaScript
      • React
      • Node.js
      • Python
      • Bash
      • Linux
      • Docker
      • GitHub Actions

    2. Software Engineer

      Sep 2022 – Jan 2024

      Developed and maintained the Wazuh Dashboard, the web interface of the Wazuh platform. Built new features, fixed bugs, and supported community users.

      • TypeScript
      • JavaScript
      • React
      • Node.js
      • Python
      • Bash
      • Linux
      • Docker

    3. IT Security Engineer

      Apr 2022 – Sep 2022

      Supported Wazuh customers with deploying and configuring the Wazuh platform, as well as troubleshooting their issues. Worked through Jira tickets, emails, and remote sessions, and also supported community users.

      • Python
      • Bash
      • Linux
      • Docker
  3. Córdoba Hosting

    Córdoba, AR

    1. Full-Stack Engineer

      Jun 2018 – Apr 2022

      Developed and maintained websites for different clients using different technologies and frameworks. Built new features, fixed bugs, and provided support to clients.

      • React
      • JavaScript
      • Node.js
      • PostgreSQL
      • PHP
  4. Legislatura de la Provincia de Córdoba

    Córdoba, AR

    1. IT Support Technician

      Apr 2016 – May 2018

      Provided support for the building's networks and infrastructure, as well as end users across different offices. Troubleshot issues and installed and configured new hardware and software.

      • Bash
      • Windows

Technologies

Languages

  • TypeScript
  • JavaScript
  • PHP
  • Python

Frameworks & Runtimes

  • React
  • Node.js

Infrastructure & Tooling

  • Bash
  • Docker
  • GitHub Actions
  • Linux
  • Windows

Databases

  • PostgreSQL
  • MongoDB
  • Redis

AI / GenAI

  • Claude
  • OpenAI
  • LangChain
  • LangGraph
  • Ollama

Get in Touch

Have a project in mind, want to collaborate, or just want to say hello? Fill out the form and I'll get back to you as soon as possible.