// signature.kt

Android
engineer
since 2010.

I build apps that millions of people use every day. Lately it's Kotlin, Jetpack Compose, and occasionally venturing into iOS via KMP. Currently based in Halifax, Nova Scotia.

// 01
val rafael = Engineer(
  name = "Rafael Tonholo",
  role = "Senior Android Engineer",
  based = "Halifax, Canada",
  stack = listOf(
    "Kotlin", "Compose", "KMP",
    "Coroutines", "Hilt", "AI",
  ),
  shipping = true,
)
// try one of the methods ->
rafael.currentlyBuilding()
rafael.writing()
rafael.hire()
// 00

Selected work

4 projects2021 - present
COMMERCIALOPEN SOURCE
- thunderbird-for-android.kt2025 - present
Thunderbird for Android
Mozilla's open-source email client coming to Android. Compose-forward, privacy-first, built in the open with the K-9 Mail community.
OSSfully open source
Mozillaaffiliated
Composemodern UI
KotlinJetpack ComposeK-9 MailOSSread case study
COMMERCIAL
- bleacher-report.kt2022 - 2025
Bleacher Report
Three years on the Android app of a top sports-media platform. Compose migrations, CI/CD overhauls, and the careful stability work that keeps apps in production at scale.
-50%release lead-time
10M+monthly users
3 yrson the app
KotlinComposeCI/CDread case study
COMMERCIAL
- pinterest.kt2021 - 2022
Pinterest
Led modularization and dynamic-feature delivery on a 9-year-old codebase. Cut clean-build time by 65% and shipped the first Play Feature Delivery integration on the app.
-65%clean build time
30feature modules
9 yrsof legacy code
KotlinPlay Feature DeliveryDaggerread case study
OPEN SOURCE
- svg-to-compose.kt2023 - ongoing
SVG to Compose
A command-line tool to convert SVG or an Android Vector Drawable (AVG) to Jetpack Compose Icons.
222GitHub stars
12contributors
v2.2.1current release
KotlinCLIComposeread case study
// 01

Currently

working on

A Kotlin to GDScript transpiler for Godot.

Bringing Kotlin's type safety, expressive syntax, and compiler tooling directly to Godot by transpiling into clean, idiomatic GDScript without heavyweight native bindings.

off the clock
// hiring_me.sh

If you're building something mobile, we should talk.

rafael@tonholo.devbook 30 min