David Coelho, Developer in Odivelas, Portugal
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David Coelho

Verified Expert  in Engineering

Software Developer

Location
Odivelas, Portugal
Toptal Member Since
May 26, 2020

David brings over 12 years of experience in web development, with a strong foundation in launching ventures that attract VC interest. He excels in sectors such as fitness, healthcare, fintech, eCommerce, and social media, showcasing a talent for innovation.

Portfolio

Shield AI
Agile Software Development, Amazon DynamoDB, Amazon Web Services (AWS), React...
One World Identity, LLC
React, HTML5, GraphQL, Apollo, Bootstrap, SCSS, MongoDB, MongoDB Atlas, Realm...
Endeavor
Cypress, Context API, Styled-components, TypeScript, React, Front-end...

Experience

Availability

Full-time

Preferred Environment

Slack, MacOS, Visual Studio Code (VS Code), Jira, Git, IntelliJ IDEA, Teams, iTerm2

The most amazing...

...thing I’ve developed is a reactive web application that covers millions of users per month without any performance issues.

Work Experience

Senior Full-stack Engineer

2021 - 2024
Shield AI
  • Architected the foundational framework of the application, setting the standards and best practices for seamless collaboration across the team.
  • Spearheaded the development of the front end for a pioneering AI platform, leveraging React, GraphQL, and MUI to create an immersive user experience.
  • Undertook critical technical decisions to engineer an out-of-the-box solution that aligned with both scalability demands and stringent project timelines.
Technologies: Agile Software Development, Amazon DynamoDB, Amazon Web Services (AWS), React, Node.js, TypeScript, Python, Java, Spring Boot, Jest, React Testing Library, Cypress, CI/CD Pipelines, GraphQL, MUI CSS, AWS Lambda

Senior Full-stack Developer

2020 - 2021
One World Identity, LLC
  • As a Senior Full Stack Engineer at One World Identity, LLC, I led the creation of an innovative web application, skillfully utilizing React, Bootstrap, Apollo, among other technologies, to craft a seamless, engaging user experience from the ground up.
  • Engineered a robust back-end service leveraging MongoDB Atlas to support a cutting-edge GraphQL server, ensuring scalable, efficient data handling and manipulation for complex application needs.
  • Orchestrated a seamless CI/CD pipeline between GitHub and Heroku, facilitating smooth transitions across development, staging, and production environments, which ensured rapid, reliable deployment cycles and enhanced product reliability.
Technologies: React, HTML5, GraphQL, Apollo, Bootstrap, SCSS, MongoDB, MongoDB Atlas, Realm, JavaScript, Front-end, Full-stack, MEAN Stack, Express.js

Front-end Developer

2020 - 2020
Endeavor
  • At Endeavor, I led the development of a cutting-edge MVP, harnessing the power of React/TypeScript and its advanced side-effect libraries to create a robust, scalable solution.
  • Pioneered the use of React hooks and the context API to construct both functional and foundational components, ensuring a seamless and efficient development process.
  • Dramatically enhanced web performance, elevating our Lighthouse score from 15 to over 60 through strategic code-splitting and meticulous codebase optimization, delivering a faster, more responsive user experience.
Technologies: Cypress, Context API, Styled-components, TypeScript, React, Front-end, MERN Stack

Ruby on Rails Developer

2020 - 2020
Clarity Diagnostics LLC
  • Spearheaded the development of client and admin portals for COVID-19 health assessments at Clarity Diagnostics LLC, leveraging Ruby on Rails and MySQL to deliver vital, user-friendly digital solutions in critical healthcare contexts.
  • Enhanced system reliability and performance by diagnosing and resolving bugs, along with optimizing MySQL queries and procedures, ensuring high efficiency and robust data management.
  • Elevated user experience by refining UI/UX through sophisticated JavaScript, SCSS, Bootstrap, and ERB template integrations, creating intuitive and visually appealing interfaces for both healthcare professionals and clients.
Technologies: SCSS, JavaScript, Bootstrap, MySQL, Ruby on Rails (RoR), Full-stack

Lead Developer

2018 - 2020
Nagarro
  • As Lead Engineer at Nagarro, I spearheaded optimization initiatives that slashed page load times from three seconds to under one second, significantly enhancing application performance through meticulous architecture evaluation and improvements.
  • As Lead Engineer at Nagarro, I spearheaded optimization initiatives that slashed page load times from three seconds to under one second, significantly enhancing application performance through meticulous architecture evaluation and improvements.
  • Championed coding excellence within the team by mentoring colleagues on best practices and conducting rigorous code reviews, fostering a culture of quality and precision in software development.
Technologies: Apollo, GraphQL, Google Cloud Platform (GCP), MongoDB, Node.js, Express.js, React, JavaScript, Front-end, Full-stack, MEAN Stack

Full-stack Developer

2017 - 2018
TheRightMargin
  • Engineered a dynamic RoR/Node.js/Express.js/React/PostgreSQL application for TheRightMargin, specializing in enhancing productivity tools for writers across desktop and mobile platforms.
  • Concentrated on developing intuitive features for managing milestones, tasks, and goals, tailored specifically to the needs of writers, ensuring a seamless and efficient workflow.
  • Delivered comprehensive full-stack development solutions, from crafting responsive React components for the front end to robust back-end architecture, driving optimal performance and user experience.
Technologies: SCSS, Material UI, Material Design, Google Material Design, TypeScript, PostgreSQL, Ruby on Rails (RoR), Ruby, Express.js, Redux-Saga, Redux, React, Front-end, Full-stack, MEAN Stack, React Redux

Web Application Developer

2015 - 2017
Brandle
  • Spearheaded front-end development for Brandle Management Tool, an enterprise-grade social media inventory and compliance platform, using Rails/JavaScript, Ruby on Rails, and MongoDB, enhancing digital asset management.
  • Played a pivotal role in architecting and coding significant sections of the application, leveraging Ruby on Rails and JavaScript, to ensure robust functionality and user experience.
  • Innovatively designed compliance features and algorithms for analyzing social media profile metadata, alongside developing customized forms for efficient data collection from enterprise employees, streamlining compliance, digital presence management.
Technologies: Bootstrap, MongoDB, Ruby on Rails (RoR), Ruby, Node.js, Angular, ECMAScript (ES6), JavaScript, Front-end, Full-stack, MEAN Stack, Express.js, React Redux

Software Engineer

2011 - 2015
Blue Screen IT Solutions
  • Spearheaded comprehensive front-end and back-end services, seamlessly integrating diverse technology stacks to meet business objectives.
  • Expertly configured and managed development infrastructure, including MEAN/LAMP servers, to architect robust, scalable websites.
  • Utilized a broad spectrum of modern web technologies to craft cutting-edge, functional web solutions, driving innovation and efficiency.
Technologies: Amazon Web Services (AWS), PostgreSQL, MySQL, MongoDB, REST, DigitalOcean, PHP, Ruby, Node.js, AngularJS, Front-end, Full-stack, MEAN Stack, Express.js, React Redux

Social Media Governance and Web Presence Management Solution

https://www.brandle.net/
In my pivotal role at Brandle, I led the front-end development of the Brandle Management Tool, an enterprise-level solution designed to streamline social media inventory and compliance. This innovative tool, built on the robust foundations of React, Ruby on Rails, and MongoDB, revolutionizes how businesses manage their digital footprints.

I was instrumental in coding significant aspects of the application, from defining compliance parameters to implementing sophisticated algorithms for analyzing social media profile metadata. My work also extended to developing customized forms for efficient data collection from enterprise employees, ensuring a comprehensive approach to social media management and compliance. This project not only showcases my technical prowess but also my commitment to delivering solutions that address complex business challenges in the digital age.

Work and Stay Protected Against COVID-19

https://claritydiagnostics.com/
For Clarity Diagnostics LLC, I played a crucial role in developing state-of-the-art client and administrator portals tailored for COVID-19 health assessments, utilizing the powerful combination of Ruby on Rails and MySQL. My contribution was pivotal in streamlining the health assessment process during a critical time.

I significantly enhanced system performance and user experience by identifying and resolving bugs, and by optimizing MySQL queries and procedures. This optimization ensured the portals operated smoothly and efficiently, facilitating a faster response to health assessments.

Moreover, I refined the user interface and experience by meticulously adjusting styles and employing JavaScript, SCSS, Bootstrap, and ERB templates. These enhancements made the portals not only more visually appealing but also more intuitive and user-friendly, ensuring that users could navigate the health assessment process with ease and efficiency. My work contributed to a more effective and engaging platform, supporting Clarity Diagnostics LLC in their mission to deliver crucial health assessment services during a global pandemic.

Endeavor Virtual Performers

http://www.endeavorco.com
At Endeavor, I spearheaded the development of a groundbreaking Minimum Viable Product (MVP), leveraging the advanced capabilities of React/TypeScript and its sophisticated side-effect libraries. This initiative was pivotal in demonstrating the project's feasibility and potential impact, setting a solid foundation for further development and innovation.

I was instrumental in engineering the core functionality of the platform, utilizing React hooks and the context API to build both functional and crucial components. This approach not only streamlined the development process but also ensured that the application was scalable, maintainable, and ready to meet the evolving needs of our users.

A significant milestone in this project was my success in boosting the application's performance, evidenced by a remarkable increase in the Lighthouse performance score from 15 to over 60. This achievement was made possible through strategic code-splitting and a thorough cleanup of the codebase, resulting in a faster, more efficient, and user-friendly product. This enhancement not only improved user satisfaction but also positively impacted SEO rankings, making the Endeavor MVP a more competitive and attractive solution in the marketplace.

Sports Card Investor

https://www.sportscardinvestor.com
For Sports Card Investor, I engineered a comprehensive digital ecosystem, crafting both a web and mobile application to revolutionize the way sports card investing is approached. My role encompassed full-stack development, utilizing React and ANTD for a seamless front-end experience, coupled with Express and PostgreSQL for robust back-end services on the web platform.

In parallel, I pioneered the development of the mobile application, employing React Native for a responsive front-end interface and architecting the back-end with AWS Lambda functions, Node.js, Express, and PostgreSQL. This blend of technologies ensured a fluid, consistent user experience across devices, catering to the diverse needs of sports card investors.

A key achievement was my adept management of the deployment pipeline across development, staging, and production environments. This strategic approach enabled smooth transitions and continuous integration of new features and fixes, ensuring the platforms remained cutting-edge, secure, and highly available for users. My contributions have significantly propelled Sports Card Investor into a leading position in the digital realm of sports card investment, offering unparalleled tools and insights.

Languages

ECMAScript (ES6), GraphQL, JavaScript, SCSS, Java, TypeScript, HTML5, CSS3, SQL, Ruby, PHP, Python, Solidity, C++

Frameworks

Angular, Express.js, Material UI, Spring Boot, Ruby on Rails (RoR), Redux, Bootstrap, NestJS, Koa, Loopback, Jest, Angular Material, React Native, Ionic, Django, Jasmine, AngularJS, Cypress, Next.js, MUI CSS

Libraries/APIs

React, Node.js, Redux-Saga, React Redux, Formik, MobX, Immutable.js, Vue 2, Socket.IO, RxJS, NgRx, Context API, Antd, Web3.js, React Testing Library

Paradigms

REST, MEAN Stack, Reactive Programming, Agile Software Development, Test-driven Development (TDD)

Storage

MongoDB, MySQL, PostgreSQL, NoSQL, Redis, Elasticsearch, Realm, Amazon DynamoDB, Databases

Other

Material Design, Styled-components, Single-page Applications (SPA), Front-end Development, Front-end, Full-stack, MERN Stack, Enzyme, Apollo, Third-party APIs, Minimum Viable Product (MVP), API Integration, Google Material Design, Serverless, Data Visualization, Blockchain & Cryptocurrency, Smart Contracts, Teams, iTerm2, Algorithms, Architecture, CI/CD Pipelines

Tools

Redux Thunk, Git, Angular CLI, GitLab CI/CD, RSpec, Cucumber, Jira, Slack, Zoom, Shell, MongoDB Atlas, IntelliJ IDEA

Platforms

Google Cloud Platform (GCP), Firebase, Heroku, Web, Amazon Web Services (AWS), Docker, MacOS, DigitalOcean, AWS Lambda, Ethereum, Visual Studio Code (VS Code)

2008 - 2011

Bachelor's Degree in Computer Science

Technical University of Lisbon - Portugal

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