Hi, I'm Luiz
👋
iOS engineer building consumer apps used by millions at work, and indie apps on the side.
LMjust launched Ritus

About

I got into iOS through a research scholarship at PUCRS and the Apple Developer Academy in 2021. Since then I've gone from founding engineer at a startup to building consumer apps used by tens of millions, while shipping my own apps like Noira Cam on the side. I share what I'm building with 22K+ people on LinkedIn, Instagram, TikTok, and GitHub, plus the occasional YouTube video. For coffee, filmmaking, and side projects, read more about me.

Want to know more about me?

Work Experience

T

TELUS Digital & WillowTree

Jan 2024 - Present
iOS Engineer
• iOS Engineer on consumer apps used by millions daily • DRI for end-to-end Search redesign and Analytics on one of NYC's most-downloaded apps • Core redesign team: major screen updates and new features from concept to production • Previously: shared SDK/UI system on an app with 90M+ downloads and 23M+ MAU; accessibility work that influenced native platform components
W

WillowTree

Jan 2023 - Jan 2024
iOS Engineer
• Started as iOS Developer Intern at WillowTree/Poatek; owned major parts of the internal mobile app • Built production features with UIKit and SwiftUI; introduced Coordinators and Clean Architecture • Contributed to a large-scale insurance application • CI/CD, unit & snapshot testing, and SOLID principles in a production engineering environment
F

Fervvo

April 2021 - Jan 2023
Founding Engineer
• Founding Engineer at an events-management startup • Led Flutter mobile development from prototype and UX/UI to App Store launch • Sole software engineer: architecture, implementation, testing, and publishing • Worked with entrepreneurs, innovation hubs, and investors on product and growth
A

Apple Developer Academy

Jan 2021 - Jan 2023
iOS Engineer (Scholarship)
• 2-year scholarship in multidisciplinary, real-world app development teams • Built multiple iOS apps with Swift, SwiftUI, UIKit, Combine, and ViewCode • MVVM architecture with a focus on accessibility and user-centered design • Strong foundation in UX/UI, product thinking, and collaborative problem-solving
S

Solinftec

Apr 2022 - Sep 2022
iOS Software Engineer
• SwiftUI development for a native app streamlining farm operations • APIs, WebSocket communications, satellite maps, and real-time push notifications • Improved usability and performance for agribusiness field teams
D

DaVInt Lab

Jan 2020 - Jan 2021
Software Engineering Scholarship
• Built automation to collect 10 years of climate news from major Brazilian media outlets • Reduced manual data work by 90%+ • Enabled n-gram and sentiment analysis for research on climate change media coverage in Brazil

Education

P

Pontifical Catholic University of Rio Grande do Sul

2019 - 2023
Bachelor's Degree of Software Engineering
Projects

I like building things

iOS apps, websites, and side projects I've shipped along the way.

iOS Apps

Apps I've built.

Websites

Sites I built and keep live

SwiftShelf

SwiftShelf

A community-driven library of production-ready SwiftUI components.

SwiftDS

SwiftDS

A SwiftUI design system with 100+ accessible components, plus SwiftBoard to browse them as a website.

Writing

Latest from the blog

How I build my apps, plus whatever I'm learning. Feedback is always welcome.

NEW
Nov 2, 2026

Why I Started Shipping the Apps I Built for Myself

Most of my apps started as things I built just for me. This year I started asking why they were only on my phone.

Oct 26, 2026

A TabNews Crash That Depended on the Xcode Version

Notes on a TabNews crash that only happened in builds made with Xcode 26.5, how I found it, and how I fixed it.

Oct 17, 2026

RAG on iOS: Grounding an On-Device LLM in Your App's Own Content

How I built retrieval-augmented generation 100% on the iPhone for Ritus, my coffee app: structure-based chunking, BM25 plus embeddings, Reciprocal Rank Fusion, a prompt budget for a 4k window, Apple's Foundation Models, and an eval that caught four real bugs.

Aug 26, 2026

Building SwiftDS and SwiftBoard: A Design System and a Playbook for SwiftUI

Two unrelated ideas, a SwiftUI design system package and a Playbook-style gallery for iOS, that ended up becoming one project. How SwiftDS and SwiftBoard work, and why they fit together.

Support My Work

If my projects helped you out, a coffee goes a long way toward keeping things like SwiftShelf free and open source.

Buy Me a Coffee
Contact

Get in Touch

Want to chat? Connect with me on LinkedIn or send me an email at contato@luizmello.dev. Happy to chat.