Mobile Developer Intern

Our engineering, trust and safety, and customer support teams work across offices in Phoenix and several other countries. Since 1986, the company has expanded from listings into payments, shipping and seller financing.

Overview

We use React Native for the customer app and Kotlin for a couple of older Android modules. You will mostly work in React Native. We are headquartered in Phoenix and have been hiring remotely since 2020. The internship is fully remote. Interns join our Phoenix team on daily calls and get a named mentor. You will need at least 4 hours of overlap with US Central time. Please make sure you have a quiet place to work and a solid internet connection.

Responsibilities

• Set up push notifications and deep links using Firebase Cloud Messaging
• Fix crashes reported in Firebase Crashlytics, starting with the most frequent ones
• Reduce app size and startup time by removing unused packages and assets
• Build new app screens in Flutter or React Native from Figma designs
• Review analytics events in Firebase to make sure new screens are tracked correctly
• Manage app state with Provider, Riverpod, Bloc or Redux, following the existing pattern

Requirements

• Based in Japan for the duration of the internship
• Currently enrolled in a bachelor's or master's degree, graduating 2026 or 2027
• Available for the full internship period
• Eligible to work in Japan
• Good written English for daily updates
• Some exposure to Firebase (Auth, Firestore or Cloud Messaging)
• Comfortable with Git and Android Studio or VS Code
• At least one app you built, shared as an APK, a store listing or a GitHub repo

Duration: 6 months

Start date: Dec 2026

Stipend: $2,250 - $2,400 monthly

Perks

• Mentorship
• Company laptop
• Flexible hours

Duration: 6 months. Start: Dec 2026.

Demo job created on 11jobs for testing and demonstrations. It is not an actual opening at Cobblegate HQ.