Fabio Espinosa, Developer in Valencia, Spain
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Fabio Espinosa

Verified Expert  in Engineering

Full-stack Developer

Location
Valencia, Spain
Toptal Member Since
September 3, 2021

Fabio is a full-stack JavaScript developer with five years of experience architecting complex software systems and building everything from databases to user experiences. He worked at CERN in Switzerland for three years with an MIT contract developing applications for classifying and producing data certification results. In his spare time, Fabio works for losestudiantes.com, a student social network designed to share posts, ask questions, and rate universities, programs, professors, and courses.

Full-stackWebSocketsCode ReviewTypeORMDevOpsJavaScriptCSSNode.jsReactPostgreSQLREST APIsSQLJSXNext.jsSequelizeMattermost

Portfolio

Los Estudiantes
React, Next.js, NestJS, PostgreSQL, HTML, Full-stack
CERN
JavaScript, Node.js, Express.js, React, Next.js, Redis, Kubernetes, PostgreSQL...

Experience

Node.js - 5 yearsReact - 5 yearsNext.js - 4 yearsTypeScript - 3 yearsNestJS - 3 yearsGraphQL - 3 yearsD3.js - 3 yearsKubernetes - 2 years

Availability

Part-time

Preferred Environment

Node.js, React, Next.js, D3.js, GraphQL, Redis, Kubernetes, TypeScript, NestJS, Amazon Web Services (AWS)

The most amazing...

...project I've developed is the central website in charge of data certification in the Large Hadron Collider (LHC) at CERN.

Work Experience

CTO

2016 - PRESENT
Los Estudiantes
  • Developed the site from the ground up to reach and maintain itself in the top 1,000 sites in Colombia. This included databases, caching, the back and front end, DevOps, and UI/UX.
  • Used SEO best practices to make the search engine traffic the #1 channel.
  • Deployed Mattermost open-source chat system for a 'chat per class' used by professors and students. White-labeled the mobile apps and published them to both major iOS and Android app stores.
  • Created 'bar chart race' visualizations to display graduate salaries for all the 345 universities on the site with D3.js and React, using a dataset of over 2.4 million records.
  • Migrated the front and back end, together with some associated services—Redis and Mattermost—to Kubernetes.
  • Implemented a blogging-type system for students to create their own blog.
  • Handled granular autoscaling during peak traffic periods.
Technologies: React, Next.js, NestJS, PostgreSQL, HTML, Full-stack

Software Engineer

2018 - 2020
CERN
  • Designed and developed the central application owning data certification in the CMS experiment, including databases, the back and front end, DevOps, and UX/UI. It handles and aggregates tens of millions of records and is used 24/7 during data taking.
  • Led the migration of four services in my unit to Kubernetes, ensuring high availability and observability.
  • Led a team to develop a functional and visually appealing user interface for visualizing each subsystem detector's status during data taking. The interface uses React and D3.js.
  • Designed and developed numerous visualizations for displaying luminosity losses per subsystem in the CMS experiment using React and D3.js.
  • Designed an event sourcing schema to track changes in data labeling per subsystem in the CMS experiment.
  • Used 'JSON logic' to create static rules which assigned automatic quality attributes to data segments in the CMS experiment.
Technologies: JavaScript, Node.js, Express.js, React, Next.js, Redis, Kubernetes, PostgreSQL, Code Review, Source Code Review, APIs, HTML, Full-stack, Python, CSS, CI/CD Pipelines, DevOps

Los Estudiantes

https://losestudiantes.com
A student social network designed to share posts, ask questions, and rate universities, programs, professors, and courses. The platform handles peak traffic periods when students are required to choose which courses to take.

I built the site from the ground up, marketed it, and used SEO tactics to make it to the top 1,000 sites in Colombia.

University List

A website where you can find and rate all the universities in the world.

For this side project, I built the whole site from the ground up, deployed it in Kubernetes, and marketed it in international environments. I also pulled photos of every university from Wikipedia and Flickr using their geolocation and displayed them on the correspondent profile.

Los Estudiantes Mobile Chat App

A mobile chat app designed to serve as a 'Slack' for students to interact with their classmates and professors with a channel for every university course using Mattermost.

I compiled and published the React Native open-source app to both major iOS and Android app stores.
2012 - 2018

Bachelor's Degree in Industrial Engineering

Universidad de los Andes - Bogotá, Colombia

2012 - 2018

Bachelor's Degree in Software Engineering

Universidad de los Andes - Bogotá, Colombia

MARCH 2015 - PRESENT

Tackling the Challenges of Big Data

Massachusetts Institute of Technology

Libraries/APIs

Node.js, React, REST APIs, D3.js

Tools

Sequelize, JSX, Expo, Arena Rockwell Simulation, React Apollo, Mattermost

Frameworks

Next.js, Express.js, NestJS, Tailwind CSS, React Native

Languages

JavaScript, GraphQL, TypeScript, SQL, HTML, CSS, Python, Java

Paradigms

DevOps

Storage

PostgreSQL, Redis

Platforms

Kubernetes, Amazon Web Services (AWS)

Other

APIs, TypeORM, Full-stack, Startups, WebSockets, Minimum Viable Product (MVP), Code Review, Source Code Review, CI/CD Pipelines, Architecture, Simio, Big Data, Apollo Server, Apollo, Web Scraping

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