I design and build web products end to end: the database policy, the API, and the last easing curve on the button.

Joan Solé

Fullstack developer at TheEtailersScroll
Portrait of Joan Solé
(About)

I’m Joan, a developer in Barcelona building generative AI products at TheEtailers. I like the parts nobody screenshots: row-level security, request budgets, a page that comes back in 64 milliseconds. And the parts everybody notices: type, motion, and how a button feels under your thumb.

Education
Computer Engineering at FIB, Universitat Politècnica de Catalunya.
Languages
Catalan and Spanish, native. English, C1.
Workflow
Claude Code as my main tool, backed by a knowledge base of decisions, incidents and lessons that every project feeds.

Selected work

(04)

01SaaS · TheEtailers2026

Picgenio

AI product photography and video for e‑commerce brands.

  1. 01Video generator with a model cascade: Kling first, Google Veo as the fallback.
  2. 02Multi-scene storyboards generated in parallel and stitched together in the browser.
  3. 03Background generation that survives navigation and reloads.
  4. 04Guided onboarding and the partner landing pages.

Fullstack developer
Next.js · Prisma · PostgreSQL · Gemini · Veo · Kling · Stripe

Visit picgenio.ai
picgenio.ai
Picgenio homepage

02Client · University2026

QusAP

A learning platform with instant automatic grading, replacing a legacy Access system at a UPC school.

  1. 01Used every week by 132 students since September 2026.
  2. 02A live class froze at 282 requests per second. One query per heartbeat later, an 80-student simulation ran with zero errors on 4% of one core.
  3. 03Course page cut from 3.5 MB to 0.41 MB; repeat navigation from 400 ms to 64 ms.
  4. 04Row-level security on all 35 tables. The grading engine runs inside Postgres.

Sole developer
Next.js 16 · Supabase · Postgres RLS · Edge Functions · Stripe · next-intl

Visit qusap.com
qusap.com
QusAP homepage

03SaaS · TheEtailers2026

Traingenio

Corporate training generated with AI: documents in, narrated lessons, quizzes and exams out.

  1. 01Built Motiongenio, which turns PDFs and slide decks into branded motion-graphics videos rendered with Remotion.
  2. 02AI script, voice narration, captions and extra languages in one pipeline.
  3. 03The learner area: AI-generated daily quizzes, final exams and progress tracking.

Fullstack developer
Next.js 16 · Remotion · Gemini · Prisma · Supabase

04Client · Nightlife2026

Club ticketing

Ticket sales and door control for a 1,000-capacity club, replacing a commercial platform.

  1. 01Online sales, promoter links, a door app that keeps working offline and a live dashboard.
  2. 02QR codes signed with HMAC. The key never leaves the database.
  3. 03Check-in is a single Postgres function.
  4. 04605 tests, including integration tests against a real database.

Sole developer
Next.js 16 · Expo · Supabase · Postgres 17 · Stripe · Wallet passes

Also built

(03)
  • Council voice agentTheEtailersA phone agent for Santa Coloma de Gramenet city council. Residents book, change or cancel bulky-waste pickups by voice, in Catalan or Spanish. Sole developer of the agent and its broker to the council's booking system.ElevenLabs · Next.js · 7 webhooks
  • TalaiaUniversity · FIB–UPCWhere and when to watch the night sky in Catalonia. Team of six: Scrum master for the first sprint, design system, map and visibility index.Expo · MapLibre · PostGIS
  • RumiPersonalA digital pet running on a local LLM. Its memory is an Obsidian vault; it dreams, and it forgets.Ollama · Node · Swift

What I do

Product engineering across the whole stack. I’m at my best where interface craft and solid systems have to meet.

  1. 01

    Interface and motion

    Design systems, type and motion that feel considered. WebGL when it earns its place, never as decoration for its own sake.

    React · Next.js · Tailwind · GSAP · three.js · Remotion

  2. 02

    Backend and data

    Postgres first. Row-level security, logic in functions, migrations that ship before the code, tests against a real database.

    Node · PostgreSQL · Supabase · Prisma · Stripe

  3. 03

    Mobile

    Expo and Swift, from HealthKit and GPS to offline door scanners and home-screen widgets.

    Expo · React Native · Reanimated · SwiftUI

  4. 04

    AI products

    Image, video and voice pipelines with fallbacks that hold up in production, plus local models when the data should stay home.

    Gemini · Veo · Kling · ElevenLabs · Ollama

Experience

(Contact)

Let’s talk.

Hiring, building something, or curious how the dithering on this page works? My inbox is open.

joansolejimenez@gmail.com