Sergio J.
Full-stack Javascript Developer
Frontend developer with 8+ years of experience, specializing in Vue.js and modern JavaScript/TypeScript ecosystems. Freelancing since 2018, building web applications for clients worldwide. Proven track record of inheriting complex legacy codebases and delivering clean, maintainable Vue 3 migrations. Currently integrating AI tooling (Cursor, Claude Code) into development workflows to accelerate delivery while maintaining code quality. Working knowledge of backend technologies (Node.js, NestJS, PHP/Laravel) when full-stack support is needed. Skills Vue 3, Vue 2, Composition API, Options API, TypeScript, JavaScript, Vuetify, Pinia, Vuex, Vue Router, TanStack Query, VueUse, Vite, Webpack, npm, Git, Vitest, Unit Testing, Component Testing, UI & Data Visualization Vuetify, Material Design, Chart.js, Responsive Design, CSS, SCSS/Sass, Ionic (Mobile Development), Auth0, OAuth, REST APIs, Axios, WebSockets, Stripe, Node.js, Express, NestJS, PHP, Laravel, MongoDB, MySQL, Cursor, Claude Code, AI assisted development, AI workflows. Speak spanish and english. Flexible schedule.
Earnings and projects
Last 6 months ÷ 6
Last 6 months: $34k
Billed in all: $272,411$272k
$17k in the last 6 months
Across 3 contracts
Across 28 contracts
Earnings, last 30 days
Skill rankings: Top 0.59% in Slack
Top 1% in 2 of 14 skills, ranked by MRR among everyone on Upwork with the skill.
- Chart.js97 freelancers · 🇪🇸 #1Top 3%🇪🇸#1 of 1
- #4ECMAScript 6155 freelancers · 🇪🇸 #1Top 3%🇪🇸#1 of 1
- #8Vuetify362 freelancers · 🇪🇸 #1Top 2%🇪🇸#1 of 1
- #17Vuex523 freelancers · 🇪🇸 #1Top 3%🇪🇸#1 of 1
- #18Slack3,033 freelancers · 🇪🇸 #1Top 0.59%🇪🇸#1 of 29
- #56ExpressJS5,651 freelancers · 🇪🇸 #3Top 0.99%🇪🇸#3 of 23
- #145Front-End Development8,892 freelancers · 🇪🇸 #3Top 2%🇪🇸#3 of 53
- #174API Development6,848 freelancers · 🇪🇸 #2Top 3%🇪🇸#2 of 39