Lucas Vieira, Developer in Florianópolis - State of Santa Catarina, Brazil
Lucas is available for hire
Hire Lucas

Lucas Vieira

Verified Expert  in Engineering

Software Developer

Florianópolis - State of Santa Catarina, Brazil
Toptal Member Since
May 30, 2019

Lucas is a full-stack engineer experienced with the latest JavaScript technologies including React, React Native, GraphQL, and TypeScript. He cares a lot about code quality and strives to write highly maintainable, scalable, and testable applications. Lucas likes solving all sorts of problems and will quickly adapt and learn new skills to overcome them.


Amazon Web Services (AWS), C, Java, Swift, React Native, GraphQL, TypeScript...
Run The Realm
Firebase, Java, Swift, TypeScript, React Native
PostgreSQL, Java, MongoDB, React, Meteor, Node.js




Preferred Environment

Vim Text Editor, Tmux, Linux, MacOS

The most amazing...

...project I've worked at, was building services for eCommerces. During a Black Friday the services would receive over 800,000 requests per minute.

Work Experience

Full-stack Software Developer

2017 - PRESENT
  • Created and maintained a React Native app that I rewrote from Ionic.
  • Developed an Apple Watch app using Swift and integrated it with React Native.
  • Built GraphQL and REST APIs with Node.js and TypeScript.
  • Integrated Apple and Google to sell subscriptions within the app.
  • Developed, maintained, and scaled a PostgreSQL database.
  • Integrated the React Native app with sensors like GPS and accelerometer. Wrote native code (Java and Swift) to make it work while the app is in the background.
  • Designed serverless APIs using API Gateway and Lambda from AWS.
Technologies: Amazon Web Services (AWS), C, Java, Swift, React Native, GraphQL, TypeScript, React, Node.js, Mobile Development, REST

Software Developer

2019 - 2020
Run The Realm
  • Built a React Native app for iOS and Android using Firebase for the back-end.
  • Worked with Android and iOS native APIs like GPS and Audio.
  • Integrated push notifications in the app and built a little framework to schedule them.
  • Developed user authentication with Facebook, Google, and Apple through Firebase.
  • Integrated Firebase - Firestore, Storage, Firebase Cloud Messaging, Crashlytics, Analytics, and Functions.
Technologies: Firebase, Java, Swift, TypeScript, React Native

Software Developer

2017 - 2018
  • Worked remote from Brazil to Norway. The five-hour time-zone gap wasn't a problem.
  • Maintained a Meteor app with React in the front end.
  • Helped with a migration from the Meteor back end to a Java back end and from MongoDB to PostgreSQL.
  • Built E2E tests using WebdriverIO.
  • Worked with reactive technology (the client and server talked through WebSockets to keep data in sync).
Technologies: PostgreSQL, Java, MongoDB, React, Meteor, Node.js

Software Developer

2014 - 2017
  • Oversaw the build and maintenance of several web apps, from the web server to the front end.
  • Maintained Node.js web servers that could scale up to handle more than 800,000 requests per minute.
  • Built a whole product from scratch from designing the database schema and building the back-end APIs to the JavaScript that runs on the client-side.
  • Worked with a lot of different teams up to 18 developers using agile methodologies.
Technologies: Amazon Web Services (AWS), Scala, AngularJS, Node.js

Assertion Library
Chai is an assertion library for Node.js. The app is very popular and has over 6,000 stars on GitHub.

I worked as one of the core maintainers of this open-source project.

Nimble is a clinician's assistant in their pocket. It allows clinicians to communicate with other physicians and nurses at a hospital.


Joga is a mobile app designed to track and improve the user's soccer skills using their smartphone or smartwatch. The app delivers a complete analysis of the player's performance on the field or on the court.


FIXME is a web app built on top of GitHub's API. The goal is to list all the issues of all the projects you are following on GitHub and sort them by the last update time so you can start fixing the oldest problems first.

It's also open source, the source code can be found here:

Joga Pro
Joga Pro uses GPS-tracking devices to track professional soccer players in the field and provide analytics in a cloud-based platform.

Data Validation with TypeScript

A little framework that I built for doing data validation using TypeScript. The framework makes it very easy to validate data and can be used for forms or validating some inputs to an API.

I plan to transform the framework into an open-source library in the near future.

Belief is an initial Promise implementation. The purpose of this library is to show that Promises are just JavaScript and to prove to myself that I could implement it.


Node.js, React, Chai, Ramda, Lodash, REST APIs, React Redux


Mocha, Vim Text Editor, Tmux, Git, Expo, AWS CLI


Spark, React Native, Express.js, Redux, Next.js, Jest, AngularJS, Angular


PHP, JavaScript, TypeScript, GraphQL, Java, Swift, Python, SQL, C, Scala


PostgreSQL, MongoDB, Amazon DynamoDB, Amazon S3 (AWS S3)


Scrum, Functional Programming, Object-oriented Programming (OOP), Mobile Development, REST


Firebase, Linux, MacOS, Meteor, Amazon Web Services (AWS), AWS Lambda, Android, iOS


Shell Commands, Software, Serverless, Amazon API Gateway

Collaboration That Works

How to Work with Toptal

Toptal matches you directly with global industry experts from our network in hours—not weeks or months.


Share your needs

Discuss your requirements and refine your scope in a call with a Toptal domain expert.

Choose your talent

Get a short list of expertly matched talent within 24 hours to review, interview, and choose from.

Start your risk-free talent trial

Work with your chosen talent on a trial basis for up to two weeks. Pay only if you decide to hire them.

Top talent is in high demand.

Start hiring