Hi! 👋 I'm
Joan Manrubia

Senior frontend engineer with 6+ years of experience. Skilled in crafting high-performance and accessible large-scale web applications to elevate the user experience and deliver measurable impact.

Experience

Download my resume here to see more details!

  • Senior Frontend Engineer

    Adevinta Canada @ Kijiji
    Toronto, ON
    Apr 2024 - Jun 2025

    Improved user engagement on web platform (500K+ daily sessions) through modern React/Next.js development and A/B-tested features. Led a 3.42% boost in replies via redesigned filters, and mentored teammates.

  • Frontend Engineer

    Adevinta Canada @ Kijiji
    Toronto, ON
    Aug 2022 - Apr 2024

    Delivered user features end-to-end with a mobile-first approach using React, TypeScript, and Next.js. Improved test coverage by 8%, led A/B experiments, and ensured performance, accessibility, and platform stability during international ownership transfer.

  • Frontend Engineer

    Adevinta Spain @ Milanuncios
    Barcelona, ES
    Dec 2020 - Sep 2022

    Contributed to a multidisciplinary squad delivering publishing and ads features, using A/B testing and feature flags for progressive rollouts. Followed a pyramid testing strategy and supported the evolution of an internal open-source design system.

  • Mobile Full-stack Engineer

    Mitto
    Barcelona, ES
    Sep 2019 - Dec 2020

    Built web and mobile apps in a fast-paced startup that raised $2M seed funding, using React, React Native, and Node.js. Improved UX and system maintainability through Domain-Driven Design and modular backend architecture.

  • Frontend Developer

    Klosions TIC
    Barcelona, ES
    Apr 2017 - Sep 2017

    Developed custom static and dynamic websites for clients using PrestaShop and WordPress, integrating modern payment gateways to enable seamless online sales.

Projects

Screenshot of CELPIP Wizard project

CELPIP Wizard

Designed to help students prepare for the CELPIP language test through interactive exercises and AI-powered feedback. The platform provides a personalized learning experience that simulates the actual test environment.

  • React
  • Next.js
  • Typescript
  • Tailwind UI
  • Server Actions
  • Prisma
  • Supabase
  • Vercel AI SDK
  • OpenAI
Screenshot of Catmapper project

Catmapper

A decentralized real estate marketplace built on Ethereum blockchain that allows users to tokenize, buy, sell, and trade real estate properties as NFTs with integrated escrow functionality.

  • React
  • Next.js
  • Tailwind CSS
  • Solidity
  • Wagmi
  • Hardhat
  • Ethers
  • Viem
Screenshot of DeFi Dashboard project

DeFi DashboardWork in progress

A modern, responsive DeFi dashboard built with Next.js, featuring real-time portfolio tracking, wallet integration, and multi-language support. Connect your wallet to view your portfolio balance with interactive charts, manage your assets, and track your transaction history.

  • Next.js
  • Tailwind CSS
  • React Query
  • Wagmi
  • Viem
  • Shadcn UI
  • Recharts
  • RainbowKit
  • i18next
Screenshot of Wandapp project

Wandapp

As a frontend engineer, alongside with a backend engineer and two product managers, we built the initial version of the platform that enables pet trainers to manage calendar appointments and track each dog’s training progress.

  • React
  • Next.js
  • TypeScript
  • React Query
  • Prisma
  • Supabase
  • Tailwind CSS
Screenshot of Video2GIF project

Video2GIF

A tool that allows users to upload a video and convert it into a GIF. It uses ffmpeg to convert the video into a GIF.

  • React
  • Next.js
  • Chakra UI
  • ffmpeg
  • Framer Motion