guillermo.casanova.b@gmail.com
Guillermo Casanova Photo

Hi, I'm Guillermo 👋

Senior Full Stack Engineer with over 4 years of experience specializing in high-performance web applications with React, Next.js, Node.js, TypeScript, and TailwindCSS. Proven track record of improving page load speeds and SEO, also shipping features for platforms serving thousands of users. Focused on leveraging modern tools to build fast, scalable, and business-centric products in a remote role.

My skills

Check some of my projects! (4)

Project screenshot for Crypto Prices

Crypto Prices

Crypto Prices with details and graphs, using the CoinGecko API.

React (NextJS) • TypeScript • TailwindCSS

Project screenshot for Anime Base

Anime Base

Anime Website where you can find a list of top rated Animes.

React (NextJS) • TypeScript • TailwindCSS

Project screenshot for Pokédex

Pokédex

Pokédex with details and pagination, using the PokéAPI.

React (Vite) • Typescript

Project screenshot for Tesla Store

Tesla Store

Tesla Store with authentication and shopping cart.

React (NextJS) • TypeScript • NextAuth

EXPERIENCE

Senior Full Stack Engineer

Jun. 2024 - Present

Freelance (Remote)

  • · Managed end-to-end project delivery for international clients, using asynchronous communication to ensure alignment across multiple time zones.
  • · Drove a 12% increase in conversion rate by re-engineering the front-end with new React/Next.js components, improving overall page load speed by over 30% through image optimization and lazy loading.
  • · Implemented a quality-first development lifecycle by architecting a comprehensive testing strategy with Vitest and React Testing Library. This reduced critical production bugs by 60% and increased code coverage to 90%, cutting manual testing time by 50%.

Stack: React, Next.js, TypeScript, Vitest, React Testing Library, JavaScript

Web Software Engineer (MACH, BCI Bank)

Oct. 2021 - Sep. 2024

Santiago, Chile (Remote)

  • · Architected and delivered the company's first internal operations platform using React, Next.js, and TailwindCSS, launching the MVP in under 2 months.
  • · Accelerated deployment time by 54% by migrating the entire CI/CD process from AWS pipelines to GitHub Actions, reducing the average build times from 15 to 7 minutes.
  • · Architected and shipped critical platform services for MACH Business B2B website, including a role-based access control (RBAC) system and a dynamic QR generation API to enable new commercial features.
  • · Enhanced developer efficiency by creating a reusable component library with 45+ components, standardizing design patterns across the team, and accelerating feature development.
  • · Drove a more predictable development cycle, achieving a consistent 87% sprint completion rate by identifying and resolving technical bottlenecks, which streamlined team workflows and minimized carryover.

Stack: React, NextJS, TypeScript, Tailwind CSS, Vitest, Shadcn UI, AWS, Firebase, Git.

EDUCATION

Self-taught learning (Udemy, YouTube, Vercel Courses, etc.)

2017 - Present

Online

  • · JavaScript, TypeScript, React, NextJS, NodeJS, Git, Modern Web Practices, etc.

Bachelor of Computer Science Engineering

Mar. 2017 - Dec. 2020

Duoc UC, Santiago, Chile

  • · Completed Bachelor of Computer Science Engineering program.

CERTIFICATES

Scrum Foundation Professional Certificate (SFPC)

Feb. 2021

CertiProf International

  • · Validated foundational knowledge in Scrum principles and practices.

LifeLong Learning Certificate (LLL)

Aug. 2021

CertiProf International

  • · Committed to continuous professional development and learning.

Scrum Fundamentals Certified (SFC)

Mar. 2021

SCRUMstudy

  • · Certified understanding of Scrum framework fundamentals.

Six Sigma Yellow Belt Professional Certificate (SSYBPC)

Feb. 2021

6sigmastudy

  • · Certified in Six Sigma methodologies for process improvement.

TOEIC Bridge

Dec. 2019

ETS

  • · International Advanced English Certificate, demonstrating proficiency in English communication for professional environments.