Fumiaki Yoshimatsu
California, United States
Summary
👤
SeniorFumiaki Yoshimatsu is a senior software engineer with 19 years of experience delivering cross‑platform applications across Android, iOS, and the web, plus backend, DevOps, and architecture work. He writes in Java/Kotlin for Android, Swift/Objective‑C for iOS, and TypeScript/JavaScript for web, with hands‑on experience in React and Next.js. He is an active contributor to the Signal Android and iOS projects, driving UI polish, bug fixes, locale handling, image support, tests, and camera UX improvements. At Hopper, he led internationalization initiatives, including an in‑app language switcher, a centralized AppLocale, and an i18n CMS built with Next.js and Google Cloud Platform tooling to streamline translations. Based in Irvine, CA, his career spans leadership and hands‑on roles at Peatix, Six Apart, AWS, and multiple startups, blending architectural vision with practical delivery and a track record of shipping scalable, localization‑driven software.
19 years of coding experience
Github Skills (15)
javas10
objective-c10
uitest10
swift10
ios10
front-end-development10
android10
xctest10
java10
testing10
image-processing9
debug8
user-interface8
debugging8
kotlin4
Programming languages (7)
Github contributions (5)
signalapp/Signal-Android
Jun 2020 - Apr 2022
A private messenger for Android.
Role in this project:
Mobile Developer (Android)
Mobile Developer (Android)Contributions:2 reviews, 41 commits, 73 PRs in 1 year 10 months
Contributions summary:Fumiaki primarily contributed to the Android application, focusing on bug fixes and UI improvements. They addressed issues related to locale display, user interface elements, and interaction behaviors within the Signal application. The user also implemented features such as lock screen fallback and improved the appearance of certain UI components in specific modes, such as RTL languages.
signalandroidkotlinmessengerjava
signalapp/Signal-iOS
Jun 2020 - Oct 2021
A private messenger for iOS.
Role in this project:Mobile Developer (iOS)
Mobile Developer (iOS)Contributions:18 commits, 24 PRs, 18 comments in 1 year 4 months
Contributions summary:Fumiaki primarily contributed to the iOS application, focusing on bug fixes and improvements to the Signal messaging app. They addressed issues related to image handling, specifically accepting HEIF/HEIC image files. The user also worked on test improvements by adding asynchronous calls and fixing tests for UI database snapshots, and handling background task deallocation. Further, the user made changes to improve the user experience with camera functionalities.
signalchatcommunicationswiftios
Find and Hire Top DevelopersWe’ve analyzed the programming source code of over 60 million software developers on GitHub and scored them by 50,000 skills. Sign-up on Prog,AI to search for software developers.