jeruko
Portrait of Joan Ruiz.

Available for freelance projects

Joan Ruiz. Software Developer & Task Automation.

I build mobile apps, fast MVPs, lightweight backends and games for startups and small companies. If you have something to build, I'm available for freelance work.

Write to me · [email protected] See the work

Selected work

Four things I've built.

01Android app · 2026 – present

WakeCast

A social alarm. Every morning, a friend's voice wakes you up.

Problem
An alarm is the same sound every morning, and nobody enjoys it. WakeCast swaps the ringtone for a voice clip a friend recorded for you.
What I did

Everything, solo: the idea, the React Native app, the Firebase backend and a native Kotlin module. I worked with Claude Code from start to finish: I decided what to build and designed the architecture, the agent wrote the code, and I checked what it produced.

What's in it: groups where one person records each day, missions like “sing them the hour”, ratings with comments and a monthly recap.

Stack
  • React Native
  • Firebase
  • Kotlin (native module)
  • Claude Code
Result
From idea to launch-ready in three months.
WakeCast on Google Play
  • WakeCast alarm ringing at 06:30 with a friend's photo, a snooze button and “swipe up to turn off”.
  • Screen revealing which friend recorded today's alarm, with the audio clip and a five-star rating.
  • Group screen for a six-member group showing who recorded today and who records tomorrow.
  • Alarm editor with a time picker set to 07:00, a label, a group and repeat days.
  • Alarm list with a notice that five people are waiting for you to record their alarm.
  • A mission delivered as a chat: “Sing them the hour”, with Decline and Accept buttons.
  • Ratings screen for a recorded alarm: 4.6 stars on average and comments from friends.
  • Monthly recap naming the group's early bird, with a chart of average alarm times.

02Research game · Umeå University · Apr – Jul 2026

Stable Bridge

A research game on spatial reasoning, for web and Android.

Stable Bridge level in a jungle: a miner with a lantern stands on a structure of stone blocks, with a crystal on the far side and hint, undo and pause buttons.
  • A level inside a lava cave with the miner, stone blocks and a crystal.
  • “Level 4 complete” panel showing hints used, total transformations and a 1 to 7 difficulty rating.
  • Level map: a winding desert path with numbered level markers.
Problem
At Umeå University's Department of Computing Science I worked on a game to study spatial reasoning. It had to run on web and Android, give hints from a tutoring agent, and record how people play.
What I did
  • Integrated the symbolic tutoring agent, which hints at which piece to use and where to place it.
  • Built the pipeline that turns the Python solver's output into around 300 playable levels.
  • Set up the Supabase (PostgreSQL) database that stores player moves and difficulty ratings.
  • Designed a custom pathfinding algorithm that simplified the game logic, with no special cases.
Stack
  • Unity
  • C#
  • Supabase (PostgreSQL)
  • Web + Android
Result
Around 300 levels, out on Google Play. I'm co-author of two papers: Advances in Cognitive Systems 2026 and Spatial Cognition 2026 (poster). The code is private.
Stable Bridge on Google Play

03Game · Bachelor's thesis · 2025 – 2026

Spaghettoni

A platformer about an artist and his workshop, suspended in space.

Spaghettoni: a tiny dark figure with bright eyes stands on a ledge among giant paint pots, brushes and the legs of an easel.
  • A cave passage in silhouette with a paint pot and brushes; the tiny figure walks along the floor.
  • A cavern lit in green, with the figure jumping over a glowing green platform.
  • A vertical shaft lit in red, full of floating shards, with a flask on a ledge.
Problem
Tell a bizarre story, an artist and his workshop floating in space, through platforming and exploration. And make it solid enough to present as my bachelor's thesis.
What I did
I designed and built it as a personal project in Godot with C#. A tiny figure among giant paint pots and brushes, and each area lit in its own colour.
Stack
  • Godot
  • C#
Result
Presented as my bachelor's thesis at Universitat Jaume I. Grade: 9.7 out of 10.
Spaghettoni on itch.io

04Game · itch.io

The Forest Heart

A pixel-art platformer in a purple forest.

What the screenshots show: you run, jump and aim your way through a purple forest, with a health bar, an energy bar, orbs to collect and one very large heart.

Problem
[PLACEHOLDER: what the game is about and why I made it (jam, coursework or personal project)]
What I did
[PLACEHOLDER: my role, and whether I worked alone or in a team]
Stack
[PLACEHOLDER: engine and language]
Result
[PLACEHOLDER: year and outcome (jam placing, grade or release)]
The Forest Heart on itch.io
The Forest Heart: a pixel-art purple forest with earth platforms, wooden walkways, purple creatures and glowing orbs; health and energy bars sit top left.
  • Start of level 1, with signposts teaching how to run, aim and jump.
  • A dark scene where a purple glow surrounds a tree and the character stands on a wooden platform.
  • A giant red heart set into the forest wall, with the character beside it.

Services

What I can build for you.

  • Mobile apps

    Apps built with React Native, plus native code when the platform asks for it. So far I've shipped on Android.

  • MVPs in a few weeks

    A first version small enough to finish and real enough to test with users. We cut the scope together, then I build it.

  • Lightweight backend

    The database, sync and server side a small product needs, on Supabase (PostgreSQL) or Firebase. Managed services, so there are no servers to look after.

  • Games

    Prototypes, small complete games, and games with a purpose such as research or teaching. Unity or Godot, in C#.

Contact

Have something to build? Write to me.

Tell me what you need in a couple of lines. I'm available for freelance projects, and I work in English, Spanish or Catalan.