Senior React Native Engineer-Canada

Zazz; Toronto; On-site; CAD 140,000 - 180,000; Full time

Job summary

Zazz is seeking a lead mobile engineer to drive delivery on high-complexity React Native screens and integrations. You will own payment integration, identity flow, and push notification architecture, while guiding the team through architecture and code standards.

Expect pairing with client engineers and leading reviews. The role requires deep React Native experience, strong TypeScript skills, and hands-on work with Hermes, Expo SDK, and native bridging to maintain TurboModules.

Qualifications

• 8+ years in mobile engineering with production React Native.
• 5+ years hands-on React Native in production.
• Experience with React Native 0.76+ and the New Architecture (Bridgeless, TurboModules, Fabric).
• Strong TypeScript, comfortable with strict mode.
• Hands-on with Hermes engine and Expo SDK 52 prebuild.
• Direct experience with TanStack Query and Zustand.
• Detox authorship for end-to-end mobile tests, iOS and Android.
• Prior integration of Apple Pay and Google Pay (tokenised payment handles).
• Prior integration of Auth0 or equivalent OIDC identity in mobile.
• Prior implementation of APNs and FCM push notifications, including token migration on version upgrades.
• Universal Links and App Links deep-link routing.
• Comfortable reading and writing native iOS (Swift/Obj-C) and native Android (Kotlin/Java) for bridging.
• Prior experience with iOS Keychain and Android Keystore for secure token storage.

Responsibilities

• Deliver highest-complexity screens and integrations across three delivery waves.
• Set engineering patterns, reference implementations, and code standards for the team.
• Pair with the client's engineers on paired-programming and knowledge transfer.
• Own payment integration, Auth0 identity flow, and push notification architecture at code level.
• Lead pull request reviews.
• Contribute to Architecture Decision Records.
• Support the four self-sufficiency exercises during hypercare (deploy hotfix, onboard from KB, restore during simulated P1, extend using established patterns).

Skills

React Native

TypeScript

Hermes

Expo SDK

Push notifications

Auth0 / OIDC

Apple Pay / Google Pay

APNs / FCM

Native bridging (iOS/Android)

TurboModules / Fabric

Code reviews

Tools

Detox

TanStack Query

Zustand

Job description

Role summary.

Lead engineer on the delivery team. Owns the highest-complexity screens and integrations.

Responsibilities.

• Deliver highest-complexity screens and integrations across three delivery waves.
• Set engineering patterns, reference implementations, and code standards for the team.
• Pair with the client's engineers on paired-programming and knowledge transfer.
• Own payment integration, Auth0 identity flow, and push notification architecture at code level.
• Lead pull request reviews.
• Contribute to Architecture Decision Records.
• Support the four self-sufficiency exercises during hypercare (deploy hotfix, onboard from KB, restore during simulated P1, extend using established patterns).

Must-have technical experience

• 8+ years mobile engineering, minimum 5 years hands-on React Native in production.
• Direct production experience with React Native 0.76+ and the New Architecture (Bridgeless, TurboModules, Fabric).
• Strong TypeScript, comfortable with strict mode.
• Hands-on with Hermes engine and Expo SDK 52 prebuild.
• Direct experience with TanStack Query and Zustand.
• Detox authorship for end-to-end mobile tests, both iOS and Android.
• Prior integration of Apple Pay and Google Pay (tokenised payment handles).
• Prior integration of Auth0 or equivalent OIDC identity in mobile.
• Prior implementation of APNs and FCM push notifications, including token migration on version upgrades.
• Universal Links and App Links deep-link routing.
• Comfortable reading and writing native iOS (Swift or Objective-C) and native Android (Kotlin or Java) at the level required to author or maintain TurboModules bridging native SDKs into React Native.
• Prior experience with iOS Keychain and Android Keystore for secure token storage.

Migration and replatform experience (required).

• Direct experience on at least one mobile replatform from native to React Native, in production.
• Understanding of auth token migration, push token re-registration, cached data reconciliation on first launch after replatform.

Industry background (preferred).

• Regulated Canadian mobile experience (public sector, transportation, financial services).
• Bilingual (English and French) app delivery experience.