Alex A. Barrios R.

Senior Web Developer & Security Expert

Contact

@alexertech@mastodon.social
LinkedIn
www.greyhat.cl

Skills

Ruby on Rails React Java & Spring Python & Django AI/ML AI/LLM Integration AI Mentoring PHP & Laravel JavaScript Node.js HTML/CSS PostgreSQL MySQL MongoDB AWS GNU/Linux App Security PenTesting (OSCP, OSWE, OSCE, OSWP) OWASP LLM Top 10 Wireless Security Agile Jira

Education

Computer Science (B.S.)

Instituto Universitario de la Frontera (IUFRONT)

Thesis: "A Game Implementation of the AI PathFinding Algorithm and the Finite States Machine"

Mérida, Venezuela | 2005 | G.P.A: 19 out of 20

Certifications

Offensive Security Web Expert (OSWE)

Credential ID: OS-AWAE-24429

Offensive Security Certified Expert (OSCE)

Credential ID: OS-CTP-03125

Key Courses

Software Security

Provider: University of Maryland (Coursera)

Hardware Security

Provider: University of Maryland (Coursera)

Professional Summary

As a Senior Web Developer with over two decades of experience, I specialize in crafting robust backend systems with a primary focus on Ruby and Ruby on Rails. My expertise extends to leading development teams and architecting scalable solutions. I am also proficient in Java, Python, and PHP, and possess strong capabilities in front-end development using JavaScript, React, and Node.js. My database proficiency includes PostgreSQL, MySQL, and MongoDB.

Beyond web development, I possess a significant background in cybersecurity, holding multiple Offensive Security certifications (OSWE, OSCE, OSCP, OSWP). This dual expertise allows me to not only create efficient applications but also to ensure they are secure by design. My experience extends to leveraging cloud platforms like AWS, including Lambda, S3, and EC2 management.

Currently, I am keenly focused on expanding my knowledge in Artificial Intelligence, particularly with Large Language Models (LLMs), and their potential applications in creating smarter, more adaptive software solutions and enhancing cybersecurity measures.

Work Experience

Senior Ruby On Rails Backend Developer / Ruby Team Lead-Manager

Current

BallastLane Applications

Remote | April 2022 – Present

  • • Led and mentored a Ruby development team, guiding architecture, enforcing coding standards, and supporting developer growth.
  • • Improved team processes and collaboration, coordinated with stakeholders for continuous delivery, and drove innovation.
  • • Actively contribute to the company's AI initiatives as a mentor, guiding developers in the effective and secure integration of AI and Large Language Models (LLMs), including practical application of the OWASP LLM Top 10 principles.
  • • Upgraded applications and managed production deployments with minimal downtime, optimizing database indexing and query performance.
  • • Migrated monolithic Paperclip file storage to ActiveStorage, added integration tests, streamlined storage, and reduced maintenance.
  • • Executed complex Ruby (2.7.5 to 3.3.8) and Rails (5 to 7.2) migrations with minimal disruption.
  • • Developed AWS Ruby Lambdas, integrated S3 with ActiveStorage, and deployed custom API endpoints on EC2 for scalable cloud operations.

Entrepreneurship (Personal Project)

Greyhat Chile

Santiago, Chile / Worldwide | August 2018 – Present

  • • Lead research and develop insightful content focusing on life, web technologies, work-life balance, and significantly, the integration and impact of Artificial Intelligence in modern applications.
  • • Delivered Ruby on Rails solutions for client projects, including e-commerce and RESTful API integrations.
  • • Increased RSpec test coverage from 65% to 90%, improving application reliability.
  • • Mentored developers as a Ruby on Rails instructor and online tutor on coding best practices.

Ruby on Rails Developer

Taller Technologies / Braintree Venmo at PayPal

Remote / US | July 2021 – December 2021

  • • Developed new features for Braintree / Venmo payment applications using Ruby on Rails.
  • • Utilized VIM/TMux, Pair Programming, and Python for automation in development workflows.

Vulnerable Machine Engineer / Senior Student Administrator

Offensive Security LTD

Remote / Worldwide | February 2016 – June 2021

Vulnerable Machine Engineer:

  • • Developed training applications in Ruby on Rails, ReactJS, Laravel, Java Spring, Django, and Node.js with PostgreSQL, MySQL, and MongoDB.
  • • Managed AWS servers and provided remote lab administration for Linux, Unix, and Windows.
  • • Researched and developed exploit/attack vectors in Python for cybersecurity training.

Senior Student Administrator:

  • • Mentored over 8,000 hours, training students for OSCP, OSCE, OSWP, and OSWE certifications, focusing on hands-on techniques.
  • • Offered guidance on offensive security methods, best practices, and problem-solving.

Senior Software Engineer

Bithaus Chile

Santiago, Chile | July 2015 – January 2016

  • • Maintained J2EE applications with PostgreSQL databases as a Senior Java Developer.
  • • Administered Amazon EC2 servers and assisted with Datadog monitoring implementation.

Founder / Entrepreneurship

Alexertech of Alex B.

Mérida, Venezuela | March 2008 – April 2015

  • • Provided Full Stack Development and Training in Java, JSP, PHP, JavaScript, CSS, XML & XSLT, PostgreSQL, MySQL.
  • • Developed a virtual classroom for IT Security and Software development courses for over 700 students, with automated student administration.