Joaquín Mussi
Frontend Engineer · Architecture & performance · Remote
I think about the product before the code.
Let's talkCareer
the same projects, ordered by time2 companies · 8 projects · 19 coursesLa Mutual de AMR
Jun 2022 – present · RemoteFrontend Engineer
Nov 2023 – presentLeading frontend architecture for internal platforms used by thousands of people, across insurance, healthcare and investment products.
- Redesigned the core web architecture, significantly cutting load times
- Defined the technology stack and engineering standards across frontend and .NET APIs
- Built full-stack applications with Next.js, React, TypeScript and .NET
- Introduced reusable component systems that eliminated duplicated UI code across products
- Established code review standards and mentored junior developers on architecture and best practices
FullStack Engineer
Aug 2022 – Nov 2023Built a platform for large-scale financial data processing and visualization. Architected component systems and API integrations for an investment product. Migrated e-commerce platform from CSHTML to Next.js, improving maintainability. Modernized legacy Angular applications to Next.js architecture.
Frontend Engineer
Jun 2022 – Aug 2022Built responsive UIs across three internal products. Implemented component systems with Next.js, TypeScript, Chakra UI and SASS.
It-techgroup
Feb 2022 – Jul 2022 · Part-timeFrontend Developer
Feb 2022 – Jul 2022Built responsive interfaces with React, Tailwind CSS and Styled Components. Implemented UI animations with Framer Motion. Delivered production-ready frontends integrated with external APIs.
See the 8 projectsSee less
Investment portfolio tool (spec-driven, SDD + TDD)
La Mutual de AMRI designed and drove the full development process of an investment portfolio tool combining generative AI with real engineering rigor: specification first (SDD), tests as a contract before implementation (TDD). This isn't “just prompting a chatbot” — it's a pipeline where every line of code comes from a verified requirement and gets validated before touching production, non-negotiable when what's on the line are financial calculations.
Next.js · TypeScript · SDD · TDD
Web3 payments platform
It-techgroup · Feb 2022 – Jul 2022Web3 platform with cryptocurrency payments. Built pixel-perfect UI with Styled Components based on Figma designs and integrated game interaction logic.
Styled Components · React.js · Axios
Booking platform
La Mutual de AMRWeb platform for cabin reservations. Served as technical lead, responsible for architecture selection, supporting trainees, and leading frontend migration from Angular to Next.js 15 with Bootstrap styling.
Next.js · Bootstrap · React.js
Financial data platform
La Mutual de AMRWeb application for processing and massive data visualization. Developed login with form validation using ChakraUI, connected backend APIs for data visualization, and ensured responsiveness across devices.
ChakraUI · React.js · Next.js · GraphQL
Digital wallet
La Mutual de AMRVirtual wallet web project. Led architecture selection, frontend development and backend integration with Zustand, Next.js 14, Sass, and NextAuth. Also led backend migration from ASP.NET Core to a RESTful .NET API.
ASP.NET · Next.js · Sass · React.js · C# · Zustand · Axios
Investment platform
La Mutual de AMRWeb platform for investment management. Created reusable components, adapted the site to multiple devices, consumed backend APIs, styled with SASS, and contributed to backend changes with C# and .NET.
ASP.NET · Next.js · Sass · React.js · Zustand
Company-wide UI component library
La Mutual de AMRReusable UI component library adopted across every product in the company, unifying design and eliminating duplicated UI code between teams.
Next.js · TypeScript · React.js
E-commerce migration from Razor to Next.js
La Mutual de AMRMigrated an e-commerce platform from ASP.NET Razor (CSHTML) to Next.js, modernizing the frontend architecture and improving maintainability.
Next.js · ASP.NET · React.js
About me
I've been working in frontend for over four years, and what interests me most is the part nobody sees: the architecture decisions that decide whether a system scales or becomes impossible to maintain.
Today I lead frontend architecture decisions for internal platforms used by thousands of people. The last redesign I led cut load times significantly.
I work mostly with Next.js, React and TypeScript. When needed I integrate .NET APIs and backend services, but my focus stays on the frontend.
Much of what I do involves systems that outgrew their original architecture: migrations from Angular and CSHTML to Next.js, reusable component systems, and code review standards so the team doesn't repeat the same mistakes.
I started Systems Engineering in 2020 and left in 2021. It was not giving up: it was a decision about how I wanted to learn. Since then I have taught myself against real problems — which is exactly what I do at work every day.
Languages
Credentials · 19See less
- TypeScript Fundamentals CoursePlatzi · Oct 2022
- Unit Testing with Jest in React CoursePlatzi · Sep 2022
- State Machines in React.js CoursePlatzi · Sep 2022
- Introduction to C# CoursePlatzi · Sep 2022
- CSS Transformations and Transitions CoursePlatzi · Sep 2022
- Advanced React CoursePlatzi · Sep 2022
- .NET Fundamentals CoursePlatzi · Aug 2022
- Introduction to Databases and SQLEducaciónIT · Oct 2022
- Introduction to Information SecurityEducaciónIT · Jun 2022
- MySQL EssentialLinkedIn Learning · Jun 2021
- Advanced JavaScript: Best PracticesLinkedIn Learning · Jun 2021
- Web Development Fundamentals: Full Stack or Front-endLinkedIn Learning · Jun 2021
- JavaScript EssentialLinkedIn Learning · Jun 2021
- ReactJS CourseCodeaRock · Mar 2022
- JavaScript CourseCodeaRock · Jun 2021
- HTML for BabiesCodeaRock · Jun 2021
- Introduction to Programming with JavaScript CourseOthers · Feb 2021
- Introduction to Programming in Python CourseOthers · Dec 2020
- HTML Fundamentals CourseOthers · Aug 2020
NorteAR
Own productUnder construction · Next.js · TypeScriptManagement system for service SMEs that measures real margin, not revenue.
See the full panel
01
Problem
A service business invoices well and by month's end there is nothing left. The system shows sales; what it does not show is how much stock was consumed to produce each of those sales — the tube of colour that yields a few applications, the product that was thrown out, the appointment that cost more than it charged.
Almost every management system measures what comes in. Very few measure what was spent so it could come in. And without that, "we sold more" and "we earned more" are the same sentence — until they stop being.
Recommendations
what the people who worked with me said4 people“Joaquín is a very capable person, persistent in pursuing goals even when they are difficult or require learning new things to achieve them. He knows when to ask for help and when to offer it to others, and is not afraid to propose and implement improvements whenever he finds them.”
“Without a doubt a great person I had the pleasure of working with, collaborating side by side on the development of an online casino where I was able to witness his outstanding React.js skills firsthand.”
“Joaquin is a very tenacious developer and excels at learning new skills.”
“Joaquín is an excellent professional, always willing to learn new things. A great teammate, charismatic and always ready to help everyone.”
Blog
technical notes4 notesWhere AI-driven development and LLM-based systems are heading, seen from a frontend engineer's day-to-day.