Eduardo Lopez, Developer in San Antonio, TX, United States
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Eduardo Lopez

Verified Expert  in Engineering

Full-stack Developer

San Antonio, TX, United States
Toptal Member Since
June 11, 2024

Eduardo is a full-stack developer with 5+ years of experience in JavaScript, specializing in React, Node.js, NestJS, and TypeScript. He also has expertise in Flutter, Laravel, Express.js, and Next.js. With an antifragile mindset, Eduardo adapts and remains resilient, fostering a high-performance culture, blending technical and strategic expertise, and applying best practices and optimization techniques. After revamping a legacy system—he cut load times by half and boosted user engagement by 30%.


Torq Holdings, Inc
Flutter, JavaScript, IT Security, Laravel, PHP, Leadership, React, Node.js...
Clevertech (DBA Lumenalta)
JavaScript, Node.js, Express.js, React, Redux, Redux-Saga, Redux Toolkit...
JavaScript, TypeScript, MongoDB, Mongoose, React, Express.js, Node.js...




Preferred Environment

Slack, Jira, JavaScript

The most amazing...

...thing I've done is revamp a legacy system with React, Node.js, Laravel, and Flutter—reducing load times by 50% and boosting user engagement by 30%.

Work Experience

Lead Developer

2023 - PRESENT
Torq Holdings, Inc
  • Led the complete UI overhaul to a minimalist interface, enhancing user experience and onboarding processes.
  • Enhanced stability by implementing event tracking tools and a credit-card-free trial system, increasing app usage and engagement.
  • Developed advanced features, including in-app tutorials, a notification system, and split payment, improving functionality and user satisfaction.
  • Collaborated closely with marketing and customer support teams to analyze data and drive targeted improvements.
  • Introduced continuous integration, event tracking, and improved payment verification systems for reliability and efficiency.
  • Transformed the menu design, introduced a sidebar and customizable company logos, and redesigned the project, estimate, map, and invoice sections for enhanced usability and coherence.
Technologies: Flutter, JavaScript, IT Security, Laravel, PHP, Leadership, React, Node.js, DevOps, AWS DevOps, CI/CD Pipelines, API Integration, Architecture, Stripe, APIs, Full-stack Development, Google Workspace, Stripe API, MySQL, Stripe Checkout, Stripe Payments, Stripe Marketplace, NGINX, Full-stack, Mobile Development, Data Integration, Dart, HTML, CSS, Progressive Web Applications (PWA), Firebase, Web Development, Web Architecture, Technical Leadership, Front-end, Front-end Development, React Query, Google Cloud Platform (GCP), Analytics, Tailwind CSS, i18n, Communication, Google Cloud

JavaScript Engineer

2022 - 2023
Clevertech (DBA Lumenalta)
  • Developed and structured features to meet client requirements, increasing user satisfaction and retention.
  • Improved the performance of several projects by analyzing the codebase, identifying areas for optimization, and implementing targeted solutions.
  • Demonstrated strong leadership skills by collaborating with team members to solve complex problems and taking on additional responsibilities to ensure project success.
  • Created and maintained workflows to implement new features and update the old ones with an organized and structured code.
  • Reduced website loading time by 20% by applying best practices in code conventions and optimization techniques, resulting in decreased bounce rates and increased user engagement.
  • Created and maintained workflows using industry-standard tools to implement new features and update existing ones with an organized and structured codebase, improving maintainability and scalability.
  • Adapted quickly to each client's specific needs, delivering projects that met and exceeded their expectations.
Technologies: JavaScript, Node.js, Express.js, React, Redux, Redux-Saga, Redux Toolkit, API Integration, Stripe, APIs, Full-stack Development, Stripe API, MySQL, Stripe Checkout, Stripe Payments, Docker, Full-stack, Mobile Development, Data Integration, Next.js, HTML, CSS, Progressive Web Applications (PWA), Web Development, MERN Stack, Web Architecture, Vue, Front-end, Front-end Development, IndexedDB, React Query, Ionic, Tailwind CSS, i18n, Testing, Communication, Jest, Sequelize, Styled-components

Back-end and Full-stack Developer

2020 - 2023
  • Achieved a faster and more efficient service by designing and implementing a microservices architecture to reduce the amount of data received and request-response time.
  • Developed a conferencing system using BigBlueButton on the back-end and server side, effectively handling the conference feature required by the platform and improving user engagement.
  • Created a tracking system that monitored working time and took screenshots regularly, using efficient algorithms to ensure optimal system performance.
  • Enhanced the functionality and user experience by implementing an online editor to create and edit documents in the platform by forking directly into a library and analyzing and modifying it to customize the behavior.
  • Delivered robust, high-performing solutions by leveraging a tech stack that includes React, Node.js, Express.js, and TypeScript.
Technologies: JavaScript, TypeScript, MongoDB, Mongoose, React, Express.js, Node.js, REST APIs, API Integration, Stripe, APIs, AWS Lambda, Full-stack Development, Lambda Functions, Google Workspace, Stripe API, Stripe Checkout, Stripe Payments, NGINX, Full-stack, Data Integration, HTML, CSS, Firebase, Web Development, MERN Stack, Web Architecture, Front-end, Front-end Development, Encryption, React Query, Google Cloud Platform (GCP), Analytics, i18n, Communication, Jest, Styled-components, Google Cloud

Full-stack Developer

2019 - 2020
  • Adapted the back end to switch from MySQL to MongoDB, enhancing the scalability and performance of the database system better to handle the increasing volume of user data and transactions.
  • Designed and implemented a robust user authentication system, ensuring secure access and protecting sensitive user information.
  • Developed a seamless payment processing system, integrating various payment gateways to facilitate smooth and secure transactions.
  • Implemented a comprehensive order tracking feature, enabling users to monitor their orders in real-time, improving customer satisfaction and engagement.
  • Ensured the platform was fully responsive and mobile-friendly, providing an optimal user experience across different devices and screen sizes.
  • Delivered a scalable architecture that supported future expansion and growth, allowing the platform to adapt to increasing user demands and new feature integrations.
  • Worked closely with cross-functional teams to design, develop, and deploy critical features, fostering a collaborative environment that contributed to the successful delivery of the project.
Technologies: Angular, Node.js, Express.js, MongoDB, MySQL, Ionic, Testing, Sequelize

At TORQ, I led the development and maintenance of a cutting-edge application designed to streamline team management and collaboration.

I was responsible for implementing key features, including recurring invoice payments and enhancing the app's functionality for managing subscriptions and automated payments. Utilizing Flutter for mobile development and Laravel for the back end, I ensured seamless performance across iOS and Android platforms. I also integrated Material UI to provide an intuitive and visually appealing user interface, significantly improving the user experience. My efforts in optimizing performance and conducting thorough testing resulted in successful releases of versions for the stores, exceeding user expectations and garnering positive feedback for usability improvements. Additionally, I developed a robust microservice architecture using Node.js with Express to handle socket connections, enabling real-time communication within the app. By leveraging Redis for connection management and RabbitMQ for message brokering, I created a scalable and resilient system that efficiently supports high volumes of concurrent users.

Led the development and implementation of several key features for Zellim, a business management platform designed to enhance organizational productivity and communication.

• Collaborative document system: I created a section similar to Notion, enabling collaborative document editing based on company permissions. This feature enhanced team collaboration by allowing real-time editing and document sharing.
• Conferencing system: I developed a robust system using BigBlueButton (BBB) and integrated Jitsi for video conferencing capabilities. I also facilitated the seamless integration of these systems within the platform, ensuring a reliable and efficient communication tool.
• Unified email integration: I established a mail connection between Google and Outlook, providing a unified email experience within the app. This integration allowed users to manage all their emails from a single source, improving productivity and streamlining communication.
• Calendar synchronization: I implemented calendar functionalities to handle events and sync them with Google Calendar. This allowed users to manage and synchronize their schedules within the app, ensuring all events were up-to-date across platforms.

Team Management Dashboard and App Enhancement for FitGMR
Developed and enhanced various components of FitGMR, a platform designed for managing and improving the performance of esports teams.

• Team management dashboard: I created a comprehensive dashboard to manage teams using React, GraphQL, and Node.js with Express. I enhanced the dashboard's user interface by adding a sidebar for quick access to various options, improving navigation and user experience.
• App optimization: I worked on the FitGMR app using React Native to fix several bugs, significantly improving the app's stability and performance. I also added new features to handle team performance, providing users with valuable tools to track and enhance their teams' productivity and success.


I led a full-stack development solution that connected customers with food companies and allowed them to order food from home.

I led the development of this solution, utilizing Node.js and Express.js on the back end and Angular, HTML, and CSS on the front end. I collaborated with my team to design and implement critical features such as user authentication, payment processing, and order tracking to provide an efficient and effective platform that met the needs of both customers and food companies.

Throughout the development process, I utilized best practices in web development to ensure the platform was responsive, mobile-friendly, and optimized for search engine visibility. Ultimately, my team and I delivered a scalable architecture that allowed for future expansion and growth of the platform, providing a seamless and enjoyable user experience.
JUNE 2024 - JUNE 2027

CompTIA Security+ ce Certification



Web Fundamentals Learning Path



Introduction to Cyber Security



Pre-Security Learning Path



APIs and Microservices



JavaScript Algorithms and Data Structures



React, Node.js, REST APIs, React Query, Stripe, Stripe API, Vue, Redux-Saga, Google APIs, Google Calendar API, Socket.IO, PayPal API


Mongoose, Stripe Checkout, Sequelize, Slack, Jira, Redux Toolkit, NGINX, GitLab CI/CD, RabbitMQ, Prisma


Express.js, React Native, Tailwind CSS, Redux, Flutter, Laravel, Next.js, Ionic, Jest, Angular


Mobile Development, Web Architecture, Testing, DevOps, Microservices


JavaScript, TypeScript, HTML, CSS, PHP, GraphQL, Dart


MySQL, MongoDB, PostgreSQL, Data Integration, Redis, IndexedDB, Google Cloud


Amazon Web Services (AWS), Firebase, Docker, BigBlueButton, AWS Lambda, Google Cloud Platform (GCP)

Industry Expertise



Full-stack, API Integration, Progressive Web Applications (PWA), APIs, Full-stack Development, Web Development, MERN Stack, Front-end, Front-end Development, Communication, Styled-components, Architecture, Google Workspace, Stripe Payments, Technical Leadership, Encryption, Analytics, i18n, Security, IT Security, Leadership, AWS DevOps, CI/CD Pipelines, Jitsi, Microsoft Graph API, Lambda Functions, Stripe Marketplace, eCommerce

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