Plannot Android & iOS
Sports club management in one place: training schedules, the club roster, attendance and invitations. Coaches take the register, admins look after members and venues, and athletes see their week. English and Portuguese.
Senior Android & Kotlin Multiplatform Engineer
Heya, I'm Rui,
aka Eyther. 👋
I build mobile apps with Kotlin and Compose Multiplatform, mentor the next wave of engineers, and tank for my friends in video games.
- Playing
- RuneScape
- Building
- Plannot & Mr. Weble
- Exploring
- Using AI without outsourcing my thinking
- Practising
- Guitar, tennis and the gym
01 / About
An engineer who likes to understand things.
I have a degree in Software Engineering and I try my best to live up to the title. I've been writing Android apps since 2019, and since 2025 I've been going deep on Kotlin Multiplatform: shared logic, native UI where it matters.
I like owning my features end to end, working closely with product and design, and leaving codebases a bit more modern and testable than I found them. I also mentor graduates, which is one of the best parts of the job: explaining something out loud is the fastest way to find out whether you actually understand it.
Away from work I tinker with everything: computers I've taken apart far too many times, home servers, open-source side projects. Curiosity is the common thread.
7+years building Android apps
1+years building with Kotlin & Compose Multiplatform
2side projects shipping now, plus 1 in maintenance
02 / Experience
The quest log.
The short version, newest quest first.
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Mindera
-
Senior Android & Kotlin Multiplatform Engineer @ Sainsbury's
- Now: moving the codebase to Clean Architecture, MVVM and Jetpack Compose, together with the team.
- Mentoring students through Kotlin Multiplatform projects.
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Senior Android & Kotlin Multiplatform Engineer @ Kingfisher Group
- One shared Kotlin Multiplatform codebase behind the B&Q and TradePoint apps, with native UI on each platform.
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Android Engineer @ YNAP Group
- Android apps for Net-A-Porter, Mr Porter and The Outnet. Brought in Jetpack Compose and improved the CI/CD pipeline.
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Hole19
-
Android Engineer
- Helped move a golf GPS app from legacy MVP to MVVM, Flow and Compose, and worked on Wear OS.
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Mindera
-
Android Engineer @ Waitrose
- Part of the team modernising the Waitrose app with Compose, Navigation and Flow, and moving CI/CD from Jenkins to Bitrise.
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Android Engineer @ Smartbox
- My first real project: the Smartbox and Smartbox Partner apps.
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Android Intern
- Built an internal HR and utility app from scratch.
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Education: degree in Software Engineering, 2016 – 2019.
Team sizes, stacks and everything in more detail: my CV (PDF) →
03 / Projects
Things I made on purpose.
Side projects and open source.
Mr. Weble Studio for two
My web studio, run in partnership with my girlfriend. Simple pages, complete solutions and custom builds for small businesses, from a photographer's portfolio to a law firm and an events venue.
Loom Open source
An Android app I designed and built entirely on my own: architecture, Compose UI, design, testing and deployment. Now being converted to Kotlin and Compose Multiplatform so it can target iOS too.
04 / AI
The Grind. ⛏️
I use AI every day, so I'm the squishy part that has to understand the slop. Training in public so you can make sure I "make no mistakes".
The routine
- A small engineering decision every weekday, answered from memory before any AI sees it.
- No-AI Wednesdays: tickets by hand, plus a lab on how Kotlin and Compose work inside. My take on No AI Fridays.
- An AI reviews my reasoning afterwards, and the result earns XP on a RuneScape-style 1 to 99 skill tree.
The skill tree
Loading the skill tree…
05 / Off the clock
The side quests.
The things that keep me me.
⚔️ WoW Forever: paladin tank, reporting for duty
I'm unreasonably excited to go back to the game I love so much, the one that wandered away from its roots. Give me a shield, a hammer and a dungeon group to keep alive, and I'll feel like a teenager again. FOR THE ALLIANCE!
--days
--hours
--min
--sec
until Azeroth calls · launch reported for 4 Nov 2026
Guitar
Slowly getting better, loudly.
Tennis
Hoping I do better at code than I do on the court.
Gym & health
Working on my health lately: the gym, alongside the tennis.
Retro gaming
I've dusted off my PS1 and PS2, but lately it's mostly the Steam Deck: I don't have much space for the big machines.
Tinkering
I've taken my computers apart more times than I can count. I started building my own home media server too, then paused it: the ready-made solutions are so much better and hassle-free.
Better cities
Public transit, streets designed for people, and high-speed rail. Infrastructure is my nerdiest non-code obsession.
Open source
I try to open source all my personal apps, rather than contributing actively to other people's projects.
06 / Contact
Say hi.
Want to talk Kotlin, KMP, side projects, trains or guitars? Reach out.