# Sergio Xalambrí

Full-Stack Web Developer · Lima, Peru (UTC−5) · Remote

[hello@sergiodxa.com](mailto:hello@sergiodxa.com) · [sergiodxa.com](https://sergiodxa.com) · [github.com/sergiodxa](https://github.com/sergiodxa) · [linkedin.com/in/sergiodxa](https://www.linkedin.com/in/sergiodxa/)

Full-stack web developer since 2013, building with TypeScript, React, Remix and React Router. I build the web app at Daffy and maintain open-source libraries with 3M+ npm downloads a month combined, used across the Remix and React Router ecosystem. I care about the Web Platform, progressive enhancement and APIs other developers find obvious.

## Experience

### Web Developer, [Daffy](https://www.daffy.org) (formerly Silverback Ventures)

_2021 – Present_

- Build the web app of Daffy, a donor-advised fund that grew into a top-10 DAF in the U.S. with more than 16,000 accounts.
- Migrated the app from Next.js to Remix in nine months with no feature freeze, running both in one server with shared sessions while routes moved over one at a time.
- Designed a Remix backend-for-frontend over the Rails API, with a schema-validated API client, generated PDF donation reports and Open Graph images.
- Extracted the patterns into Remix Utils, Remix Auth strategies and remix-i18next, now open-source libraries other teams build on.

### Frontend Lead, [Able](https://able.co)

_2018 – 2021_

- Led the frontend architecture of an internal product being prepared for public launch, building with React against a Rails backend.
- Wrote the initial frontend curriculum for Codeable, Able’s full-stack bootcamp, and taught its React course.

### Support Engineer, [ZEIT](https://vercel.com) (now Vercel)

_2017 – 2018_

- Helped customers deploy to Now and adopt Next.js, building sample apps for their use cases.
- Worked on the documentation of ZEIT’s API, so customers could learn the platform without a support ticket.

### Frontend Developer, [Platzi](https://platzi.com)

_2015 – 2017_

- Built the live classes system, discussions, the video player and React server rendering on the Django platform of a YC-backed online school.
- Open-sourced Pulse Editor, Platzi’s Markdown editor, and Pulse, its Electron desktop app; taught web development courses.

## Open source

- [Remix Utils](https://github.com/sergiodxa/remix-utils): Utilities for routes, responses, server-sent events, CSRF and more. (1.6M downloads a month, 2.3k stars)
- [Remix Auth](https://github.com/sergiodxa/remix-auth): Authentication for Remix and React Router apps, with dozens of strategies. (650k downloads a month, 2.2k stars)
- [remix-i18next](https://github.com/sergiodxa/remix-i18next): Translations for Remix and React Router apps with i18next. (700k downloads a month)
- [The @sdxc packages](https://sdxc.dev): 130+ packages and a CLI for full-stack apps on Web Platform APIs and Cloudflare Workers.
- [Contributor](https://github.com/sergiodxa): Remix, React Router, Next.js, SWR and micro.

_Figures from GitHub and npm, October 2026._

## Talks and writing

- [The Remix Way](https://www.youtube.com/watch?v=o07u1oKE6VA): Remix Jam 2026, Toronto, 2026
- [Remixing How We Give](https://www.youtube.com/watch?v=eh6FfHFpYMM): Remix Conf Europe 2022, 2022
- [Hundreds of articles and tutorials](https://sergiodxa.com): sergiodxa.com, 2013 – Present

## Skills

- **Languages and frameworks:** TypeScript, JavaScript, React, Remix, React Router, Next.js, Node.js, Bun
- **Platform:** Cloudflare Workers, D1, KV, Durable Objects, Express, Rails APIs, SQL
- **Practices:** Authentication (OAuth 2.0, OpenID Connect, passkeys), testing with Vitest, accessibility, progressive enhancement, library and API design, technical writing

## Education

- **Self-taught:** Web development courses at Mejorando.la, now Platzi (2013 – 2015).

## Languages

- **Spanish:** native
- **English:** fluent