It always seems
impossible until it’s done.

MARIO ZELAYA • ENGINEER | IT | DEVOPS | PROGRAMMING | SUPPORT | QA

About.

PROFESSIONAL SUMMARY.

Dedicated Computer Science Engineer with over 14 years of experience in web development, IT, support, and technical consulting. Skilled in building and optimizing websites using WordPress with a focus on delivering user-friendly solutions. Proficient in managing VPS environments, cloud services, and IT infrastructure, with a proven ability to resolve complex technical issues and improve operational efficiency. Adept at working remotely, with strong communication skills and a commitment to driving business success through technology.

Work.

RECENT PROJECTS.

AI Automation

  • RAG assistant: Built and deployed a WhatsApp-based Retrieval-Augmented Generation assistant in n8n, integrating Chatwoot, Evolution API (WhatsApp), OpenAI models (GPT‑4.1 and GPT-5; backup Google Gemini 2.5 Pro) to automate customer interactions.
  • Infrastructure: Configure, Secured and operated a VPS Stack (Ubuntu, Docker, Coolify) on a custom domain (evolveapi.uk); implemented self-hosted Redis for message buffering, Qdrant for vector search, and PostgreSQL for persistent chat memory.
  • CRM integration: Designed and shipped a lightweight CRM API to connect the WhatsApp RAG assistant with the company’s CRM.
  • Workflow automation: Authored multi-stage n8n workflows handling text, images, audio, and files to provide real-time support across WhatsApp and WordPress.
  • Delivery: Completed the end-to-end implementation in three months, rapidly upskilling via a focused Udemy course on n8n and API automation.

Achievement: Reduced manual customer support workload by 60%, with ongoing tuning to improve response accuracy and user experience.

Web Development and deploy on Ubuntu VPS

  • Built and deployed CRM: Delivered a Laravel 12 CRM on Ubuntu VPS with Nginx, PHP, MySQL, and SSL/TLS, centralizing customer management, services, and quoting workflows for hosting operations. Continue iterative enhancements using AI-assisted development.
  • Shipped n8n/WhatsApp API: Designed REST endpoints for customer/lead management, service info, payment details, and quote generation/PDF download, secured via X-API-Token middleware; published live docs at /api/documentation with Postman collection and test script. Added advanced customer search (email, name, company, domain, phone, generic q).
  • Version control: Managed collaborative workflows with Git and Bitbucket.
  • Achievement: Increased team throughput by ~40% via faster pages and simpler workflows. Enabled WhatsApp automation through n8n using authenticated APIs, reducing manual lookups for customer/service data.

  • Developed and enhanced a Laravel 8-based clinic management application (Doctorsys) using PHP, MySQL, Nginx, and Ubuntu VPS, improving functionality for a healthcare client via AI-assisted coding.
  • Configured and deployed the Doctorsys Laravel application on an Ubuntu VPS, setting up Nginx and securing the environment with SSL.
  • Implemented Git and Bitbucket for version control, streamlining code updates and collaboration.
  • Achievement: Enhanced clinic application performance by 25% through optimized database queries and modernized UI, improving user experience for healthcare staff.
  • Demo URL: https://app2.techbit.dev/

  • Built a lightweight web application using PHP 8.0, MySQL, Bootstrap, jQuery, and Ajax, with PDO for secure database interactions.
  • Designed a MySQL database to manage patient records, improving data organization for clinic staff.
  • Created a responsive, user-friendly interface with Bootstrap, enhancing accessibility.
  • Repository: https://github.com/mariozelaya23/clinicpos
Some WordPress Projects

  • Clinic: https://uroginecologiasv.com
  • Online radio: https://radiocentroamericana.net
  • RH: https://sinergiahumana.net
  • Tech: https://ercasv.com
  • Farm: https://nutriavicola.sv
  • Workforce: https://etp.selacowdb.com
  • Farming: https://coriasa.com
  • Spare parts: https://munfresa.com
  • Textile: https://renedisv.com
  • Research: https://oquelicenter.org
  • Transportation: https://sglogisticsv.com
Other projects deployed on Ubuntu VPS and VPS management

Configure, Secured and operated a VPS Stack (Ubuntu, Docker, Coolify) on a custom domain (evolveapi.uk); implemented self-hosted Redis for message buffering, Qdrant for vector search, PostgreSQL for persistent chat memory, Chatwood and Evolution API to connect the company WhatsApp.

  • Matrix-Synapse was set up on a Linux Ubuntu server for private communication.
  • In summary, the server setup involves:
    – Installing the Matrix deb package (repository)
    – Installing matrix-synapse-py3
    – Configuring PostgreSQL
    – Configuring Nginx
    – Configuring Cerbot SSL
    – Testing the server with a client. In this case, I used the Elements app, which is similar to WhatsApp.

Matrix-Synapse Server URL: https://nuntius.uk/_matrix/static/

  • Joplin was installed as an alternative to using a commercial note-taking application.
  • In summary, the Joplin installation involved:
    – Configuring the docker-compose.yml file
    – Configuring PostgreSQL
    – Configuring Nginx
    – Configuring Cerbot SSL

Joplin Server URL: https://joplin.nuntius.uk/

  • In summary, the OpenVPN installation involved:
    – Download and install the OpenVPN script file.
    – Configure the OpenVPN installer.
    – Create a new OpenVPN user and download the configuration file.

  • In summary, the N8N installation involved:
    – Configuring the docker-compose.yml file
    – Configuring Nginx
    – Configuring Cerbot SSL

N8N Server URL: https://n8n.techbit.dev/  (allowed access to ONLY one IP)

  • In summary, configure WordPress websites on a VPS involves:
    – Install PHP and necessary extensions
    – Adjust PHP Settings
    – Install MySQL
    – Install Nginx
    – Create WordPress folder
    – Create MySQL WordPress database
    – Setup wp-config.php including database Settings
    – Set folders permissions
    – Configuring Nginx
    – Configuring Cerbot SSL

Websites URL:

  • https://techbit.dev/
  • https://getdoctorsys.techbit.dev/
  • https://mzelaya.techbit.dev/

Work Exp.

Server Net Hosting – Remote, Colombia – Laravel Developer and Tech Consultant

April 2025 – Present

Server Net Hosting – Remote, Colombia – AI Automation and Integration Engineer

June 2025 – Present

CLINEFEM – Remote, El Salvador – Tech Consultant and Laravel Developer

August 2024 – March 2025  

LOGICUBE – Chatsworth, California – Senior Technical Support & Applications Specialist

February 2021 – July 2024

CLINEFEM Clinic – Remote Project, El Salvador – Web Developer and Tech Consultant

January 2022 – July 2022

SELACO – Cerritos, California – IT Program Analyst II

August 2020 – February 2021

Hosting de El Salvador – Remote, El Salvador – Web Developer and System Administrator

May 2018 – July 2020

Soluciones Eficaces – San Salvador, El Salvador – IT System Administrator

January 2014 – May 2018

Outsourcing Services International | OSI – San Salvador, El Salvador – Software Quality Assurance Engineer

January 2013 – January 2014

Rulesware – San Salvador, El Salvador – Software Quality Assurance Engineer

January 2012 – January 2013

Hipotecario Bank (Banco Hipotecario de El Salvador) – San Salvador, El Salvador – Tech Support Specialist

January 2011 – January 2012

Skills.

  • Git – 4 Years

  • Docker – 3 Years
  • Jira – 4 Years
  • SQL Server – 7 Years

  • AI – 3 Years

  • MySQL – 7 Years

  • Active Directory – 5 Years

  • Python – 5 Years

  • IT – 8 Years

  • Robot Framework – 4 Years

  • Technical Support – 7 Years

  • Bash – 7 Years

  • PHP – 4 Years

  • Laravel – 2 Years

  • Linux – 10 Years

  • WordPress – 10 Years

  • N8N – 1 Year

  • API Integration – 1 Year

  • REST API – 1 Year

Courses.

Course Description: Build LLM Apps & AI-Agents with n8n & APIs
Automate Everything: n8n, LLMs, OpenAI API, Deepseek, Ollama & RAG! Business & Private AI Agents; More than just ChatGPT.

Course description: 

  • Develop and debug code in the C programming language
  • Discover the foundations of computer programming and Linux, the command line, manage processes, files and memory, compile C code with Linux
  • Interpret, analyze, and implement important computer algorithms
  • Observe, manipulate, and optimize computer memory using pointers in the C programming language

Course description: Learn data structures and algorithms to build robust applications with Python and SQL in 16 weeks. Use DevOps tools and deploy to the Amazon AWS, Microsoft Azure and Google clouds.

Course Description:

  • Use robot Robot Framework test automation tool plus libraries like Selenium Webdriver, API, Database, XML, Files, etc.
  • Execute Robot Framework automated tests from a command window, batch files, Jenkins, and Windows task scheduler.
  • Understanding of HTML Tags & Attributes, CSS, and Bootstrap.
  • Automate complex interactions across multiple web applications.

Course Description: From managing global settings to configuring advanced security, this course details the process of successfully managing an enterprise implementation of Office 365. Learn how to adjust user and subscription settings, configure Exchange mailboxes and groups, set up SharePoint sites, manage Microsoft Teams, and perform advanced configurations, such as multifactor authentication and PowerShell scripting.

Contact.

LET’S TALK.

  • Phone number: 310-709-6573
  • Email: mariozelaya23@gmail.com
  • LinkedIn: https://www.linkedin.com/in/mario-zelaya-1abb12155