Profile Pic

Lucas Fernando Geron

Software Engineer

Full Stack Developer

Ruby on Rails • React

Last updated: Jan 1, 2026
I am ambitious and proactive, always seeking challenges that allow me to grow professionally and contribute to the financial success of the company I work for. I am extremely organized and enjoy participating in important projects, whether as a leader or as an active member of the team, always working with clear goals. Good communication and respect are parts of my work routine.
Soft Skills
  • Analytical Thinking
  • Problem Solving
  • Clear Technical Communication
  • Ownership and Accountability
  • Collaboration in Cross-functional Teams
  • Continuous Learning Mindset
Core Competencies
  • Full Stack Web Development
  • API Design and Integration
  • CI/CD Workflow Design and Automation
  • Real-time Communication Systems
  • Scalable Architecture and System Design
  • AI Integration and Prompt Engineering
  • Observability and Monitoring
  • Performance Analysis
CodeMiner42

Software Engineer

Ruby on Rails

Jan 2024 — Present (+2 years)
São Paulo, SP, Brazil | Remote
CodeMiner42 Logo

I joined CodeMiner42 through their trainee program (2024/1). Over three months, I participated in training where I honed my skills by solving programming challenges and participating in a series of internal workshops and mentoring sessions. Since then, I have been assigned to support clients while continuing to contribute to CodeMiner42 blog Writing posts that include tutorials, relevant tips, summaries of events I've participated in, and current affairs.

In December 2024, I won the internal Hackathon CodeMiner where I contributed to the development of a password manager application successfully without leaking any sensitive data, a relevant challenge worth mentioning here.

Software Engineer

Ruby on Rails, Python

Sep 2025 — Dec 2025 (4 months)
New York City, NY, USA | Remote
Sentrel Logo
About the Project

Sentrel is a solution that integrates AI agents into government organizations. The product focuses on handling inbound phone calls and, through an AI agent, providing support for requested inquiries with access to internal information and the ability to respond appropriately, collect relevant data, create requests, send notifications, and escalate issues to the responsible departments when necessary.

About the Experience

At Sentrel, I worked on the full-stack engineering and development team, actively participating in decisions about the application's architecture, including technologies, database schema, hosting and monitoring services, as well as coordinating development tasks and demands for the team. The application went from scratch to production deployment in just over a month.

Main Contributions
Real-time dashboard without reload
In addition to the main application layout, I developed the core pages with real-time updates using Hotwire. The call dashboard and the live calls transcripts are updated without needing to reload the page.
RAG capabilities for the agents
Implemented functionality enabling the agent to consume information using RAG (Retrieval-Augmented Generation). The search flow leveraged keywords to improve retrieval, delivering highly accurate responses.
UI componentization
Using View Components in a Rails monolith, I created a set of reusable components to standardize the interface and accelerate development.
On-demand SMS delivery
Through Twilio integration, I implemented the ability to send limited information such as addresses, phone numbers, emails, and links via SMS.
Playground and Sandbox environments
Given that the core of the application operates via phone calls, I developed a playground environment where users could interact with the agent via text or place calls before production. A sandbox environment was also configured with partner service integrations, enabling function calling, knowledge base queries, and the use of custom credentials.
Multi-environment deployment and CI/CD
Designed and implemented CI/CD workflows for GitHub and Heroku, automating deployments. The pipeline included test verification (RSpec), code quality checks (RuboCop), vulnerability scanning (Brakeman and Audit), and coverage reporting (SimpleCov).
Usage reports and metrics
Leveraging application data, I developed metrics visualizations, including heatmaps of calls received by hour and day of the week, rankings of the most frequent topics discussed, call volume by department, and resolution rates by AI versus escalations, with multiple filtering options.
Multi-agent configuration
As each client could choose different providers for TTS (Text-to-Speech), LLM (Large Language Model), and STT (Speech-to-Text), and each agent had access to its own toolset, I designed an orchestration approach to manage these configurations reliably and efficiently.

Full Stack Developer

Ruby on Rails, React

Apr 2024 — Aug 2025 (1 year, 5 months)
Boston, MA, USA | Remote
Vanta Logo
About the Project

Vanta is a platform specialized in e-sports coaching for schools that also promotes tournaments across multiple modalities and games within local, state, and national leagues. The application provides a virtual environment that enables simultaneous streaming of players and their gameplays.

About the Experience

At Vanta I worked primarily as a back-end developer with frequent contributions to the front-end. It was an incredible experience where I was able to collaborate over time on several important platform features, from integrations with third-party services, improvements to the user experience, development of new features and performance optimizations.

Main Contributions
Verizon Innovative Learning Integration
I developed an OAuth-like API to securely link user accounts with VIL Integration with their Vanta Accounts, enabling exclusive access to leagues sponsored by Verizon.
Check-in System
I was responsible for implementing the backend logic for the match check-in process, which included automated reminders and real-time notifications to users. This system significantly reduced the number of forfeits, improving overall engagement and reliability of the platform.
Event Page Redesign
I was responsible for implementing the new event navigation experience based on layouts provided by the design team in Figma. My work focused on translating the visual concepts into a fully responsive and intuitive interface, ensuring consistency across devices.
Marketplace
I built a flexible marketplace module where items and content could be managed via YAML files, allowing for rapid updates without code changes. Products are managed by the marketing team through the admin dashboard, making it easy to launch new offers. The marketplace was integrated with HubSpot for purchase tracking and order management, streamlining the sales process for both users and admins.
Arena Enhancements
I implemented advanced features in the Arena module using Stream.io, such as ‘remote mute’, ‘raise hand’, and individual audio controls. Additionally, I improved the device preview and selection process, making the virtual event experience more interactive and accessible for all participants.
Demo Environment
To support the sales team, I designed and deployed a sandbox environment that allowed for safe demonstrations of the platform. This included automated data resets and a custom logger to track setup steps, ensuring each demo started from a clean state and reducing manual preparation time.
Google OAuth Integration
I integrated Google authentication using NextAuth.js, supporting multiple user roles and custom onboarding flows. Each user role required different information and registration steps, which made the authentication flow more complex and challenging to implement. By mapping out and handling these scenarios, I ensured a seamless onboarding experience for all user types. This not only simplified the registration process but also led to a measurable increase in new user sign-ups.
Quantum League
I led the redesign and implementation of most pages related to the Quantum League, a sponsored league that required extensive changes to the platform. My work included creating and customizing new components to match the league's branding, as well as adding features such as live broadcasts directly within the platform and custom ad transitions between the lobby and the arena. All these features were fully managed by the marketing team through the admin dashboard, providing greater flexibility and promoting visibility for the sponsored ads.
Queue Matchmaker System
I developed the backend for a real-time matchmaking system using Redis and Pusher, ensuring that matches were balanced and that the system could handle high traffic without performance degradation. This feature was submitted to a stress test, and the results were impressive.
General Improvements
Throughout my time at Vanta, I proactively upgraded core dependencies (Ruby, Rails, ActiveAdmin, and others), introduced impersonation features for support staff, optimized CI/CD pipelines, refactored Next.js codebase from Pages Router to App Router, for better maintainability, enforced code standards with ESLint, and set up preview deployments branches on Vercel for faster feedback during development.

Backend Developer

Ruby on Rails

Jan 2024 — Mar 2024 (3 months)
São Paulo, SP, Brazil | Remoto
Trainee 2024/01 Logo
About the Project

The Codeminer42 Trainee Program is a continuous education project lasting 3 months where we learn to solve real problems, improve research skills, teamwork, communication, and software development accompanied by experienced mentors from the company.

About the Experience

During the trainee program, I participated in weekly training sessions, programming challenges, and internal workshops and mentoring that helped me improve my technical skills and teamwork skills in software development.

Limber Software

Backend Developer

Ruby on Rails

Sep 2023 — Dec 2023 (4 months)
Pato Branco, PR, Brazil | On-Site
Limber Software Logo

Limber Software was a gateway to my professional software development experience, where I learned to work in a team, to handle deadlines and demands in a manageable way, managing and estimating deadlines for the delivery of my tasks. I also learned to open and review PRs taking into account the project and the maintainability of the code, and how to use Git resources in collaborative projects.

During my experience at Limber Software, I explored the project to the fullest, learning a lot about the standards and best practices of a mature codebase, as well as improving my skills in Ruby on Rails and other complementary technologies. I worked on various features, bug fixes and performance improvements, always striving to deliver high-quality code and contribute to the success of the product.

Backend Developer

Ruby on Rails

Sep 2023 — Dec 2023 (4 months)
Pato Branco, PR, Brazil | Remote
WayV Logo
About the Project

WayV is an enterprise-level and industrial form management platform. The application allows the creation and distribution of customized forms, with various field types, conditional logic, and response validation. Forms can be answered in stages, publicly or privately, and responses are stored in a non-relational way, allowing flexibility in the structure of the collected data.

About the Experience

I contributed to the platform's development by implementing improvements to the form questions' settings, adding conditional validation rules as well as validation of the responses. Throughout the work period, I prepared a report with more than 25 possible improvements, presenting the problem to be solved, the solution that should be applied, and the benefits of each for the repository/product.

Self-Employed

Full Stack Developer

Ruby on Rails

Nov 2022 — Sep 2023 (11 months)
Guarapuava, PR, Brazil | On-Site
Self-Employed Logo

After 7 years working as a manager at a graduation company, I decided to change careers and pursue my passion for software development. Since then, I have been working as a freelance backend developer, primarily focusing on projects with Ruby on Rails.

I completed my degree and turned my final project into a product. I ventured into the world of start-ups in search of practical experience and learning, where I was able to enhance my technical and business skills.

BioLab

Software Engineer

Ruby on Rails, React

Sep 2023 — Dec 2023 (4 months)
Pato Branco, PR, Brazil | On-Site
BioLab Logo
About the Project

BIOLAB was a start-up conceived to offer a training platform and simulated training for biomedical professionals. The platform aimed to provide a broad collection of clinical cases and medical reports, as well as the corresponding microscopic samples, allowing professionals to improve their diagnostic and laboratory analysis skills in a virtual environment.

About the Experience

I prepared the documentation for an application that will be developed, with artifacts such as: database schema, user interface (UI/UX) prototypes, requirements gathering, and product roadmap. I also prepared the material used to present the project in investment rounds and the plan to enter and scale product sales to the target audience.

FORMAgestor

Full Stack Developer

Ruby on Rails

Apr 2023 — Dec 2023 (9 months)
Pato Branco, PR, Brazil | On-Site
FORMAgestor Logo
About the Project

FORMAgestor is a web application developed to be used by the commercial sector of graduation companies, proposing significant improvements in the way of managing their negotiations through the proper registration of information in the system. By registering both successful and unsuccessful negotiations, the application enables the extraction of valuable market statistics and insights about the graduation market.

About the Experience

I implemented significant improvements to the application described below (Graduation Project), making it fully responsive, optimizing database queries, tests, validations, and resources with hotwire. I made the application scalable and implemented an administrative dashboard for customer and license control, enabling shared use of the platform for customers who operate as franchises. I also developed some curricular enrichment projects using various technologies such as landing pages, blog with image gallery, task list, record management through APIs, among others.

Graduation Project

Full Stack Developer

Ruby on Rails

Nov 2022 — Jun 2023 (8 months)
Guarapuava, PR, Brazil | On-Site
Graduation Project Logo
About the Project

Based on my experience in the graduation market, where I worked for 7 years as a manager of a graduation company, I developed the project that was carried out as a Final Course Project at UTFPR, developing an application capable of managing negotiations and mapping classes for graduation companies. Given the market potential, this project became the FORMAgestor product.

About the Experience

I developed a Ruby on Rails application, from problem conception to production launch. The application has Docker support, AWS S3 integration, and uses the main Ruby Gems, and was hosted on Heroku. The application has test coverage and CI/CD configuration.

Technology in Internet Systems

U.T.F.P.R - Campus Guarapuava

July 2015 - June 2023
Graduated

Suspended in 2018/2 and resumed in 2022/2 due to pandemic.

Bachelor of Computer Engineering

U.T.F.P.R - Campus Pato Branco

July 2011 - December 2013
Dropout

Course geared towards hardware and not much towards software.

English Proficiency: B2

Startup Weekend Pato Branco

Techstars • 2023

54 Hours

Investment in Real Estate Funds

Suno Research • 2022

10 Hours

Excel + Power BI

Outstanding Student

Softgraf Guarapuava • 2022

70 Hours

Training for Leaders

Kellen Kretschmer Training • 2021

20 Hours

Complete Course of Rub

OneBit Code • 2020

5 Hours

Communicate

Outstanding Student

Kellen Kretschmer Training • 2019

24 Hours

Laravel 8.0

Especializa T.I • 2018

6 Hours

Social Media Strategist

Plugcitários • 2018

12 Hours