AuraSeason
A native iOS utility that visualises the progress of seasons, years, months, days, and personal milestones across widgets and Live Activities.
Tech: SwiftUI, SwiftData, WidgetKit, ActivityKit, RevenueCat, App Intents
Hi, I'm Mateusz.
I'm a product builder
based in Warsaw, Poland.
By day Product Owner at Assembly Global.
By night I make small, AI-powered tools and apps.
Bridging the gap between product strategy and rapid engineering.
In the past year, I've shipped native iOS apps, a full-stack SaaS product, and AI-powered publishing tools. Luma Breathwork reached a 13.3% App Store conversion rate and keeps evolving, AuraSeason is live on the App Store, and Daily Word turns a daily content ritual into a full product pipeline.
Currently open to new projects & roles
Recent Projects
Dopóki Życie Trwa
A dark, brutalist editorial magazine about discipline, stoicism, and the body. WebGL shaders, cinematic scroll animations, Sanity CMS, and newsletter — built solo in two weeks.
Tech: Next.js 16, React 19, Sanity CMS, Three.js / R3F, GSAP, Tailwind CSS 4
Luma Breathwork
A breathwork app for iPhone and Apple Watch, expanded with watch support, Health integrations, richer stats, stronger haptics, and ongoing product updates.
Tech: SwiftUI, watchOS, HealthKit, WatchConnectivity, SwiftData, Swift Charts
Daily Word
A Polish daily readings product combining scraping, AI summaries, generated visuals, caching, and newsletter delivery into one calm daily experience.
Tech: Next.js 16, React 19, Supabase, Gemini API, Groq, Cheerio, Resend
Lemmi Studio
A tool that turns raw app screenshots into ready-to-use App Store visuals, marketing copy and landing pages. Built to help indie developers who ship fast but don't have time for design or copywriting.
Tech: Node.js, React, Supabase, Gemini API, Stripe
Feeling Journal
Emotion tracking app for iOS that helps users reflect on emotional patterns with weekly AI-generated summaries. Built from idea to App Store in one week.
Tech: SwiftUI, SwiftData, CloudKit, Gemini API
Calm Now
A minimal, calming box breathing experience built in two weeks to explore focused UI design and StoreKit paywalls.
Tech: SwiftUI, SwiftData, CloudKit, StoreKit
What others say
"Incredible app. Simple, clean, and gets straight to the point. The Apple Watch integration is flawless and it actually helps me calm down during busy workdays. Highly recommend!"
App Store ReviewLuma Breathwork user
My Process
I don't just write code – I focus on solving user problems and delivering business value fast:
1. Spot a real problem with measurable impact
2. Design a lean, "good enough" MVP
3. Build rapidly leveraging AI and a modern stack
4. Ship early, gather data, and iterate
Bridging the gap between a Product Owner's product strategy and an engineer's execution.
Stack
Languages
Python · Swift · SQL · JavaScript
Frontend & Backend
React · React Native · Next.js · Express.js · FastAPI · Flask · Firebase · Supabase
AI & Data
OpenAI · Gemini · Anthropic Claude · Perplexity · BigQuery
Automation
n8n.io · Make.com · Postman
Development Tools
VSCode · Xcode · Cursor · Git · GitHub · Docker
Product & Design
Figma · JIRA · Notion · Hotjar