Contract Full Stack Java Developer Jobs in New Haven, CT

We're looking for an experienced mobile engineer to help build and improve the Subway app on iOS and Android — the app millions of guests use to order food, manage their loyalty rewards, find nearby restaurants, and check out with their preferred payment method.

You'll work in a collaborative product team alongside designers, product managers, and other engineers, shipping features that are fast, reliable, and polished. App performance is a core priority: every change is expected to maintain or improve speed metrics we track rigorously.

Our mobile stack in plain terms:

Framework

React Native (cross-platform iOS & Android) + Expo

Language

TypeScript (strict mode) — strongly typed throughout

State Management

Redux Toolkit for app-wide state; MMKV for fast local storage

Navigation

React Navigation

Payments

Adyen, Apple Pay, Google Pay

Auth

AWS Cognito (token-based login/session management)

Testing

Jest, React Native Testing Library, Maestro (end-to-end)

CI/CD

GitHub Actions, Expo Application Services (EAS), Fastlane

Error Tracking

Sentry

Feature Flags

LaunchDarkly (controls which features are live for which users)

Analytics

Adobe Experience Platform, Quantum Metric

• Build and maintain app features across the full stack of the mobile experience — ordering, menu, cart, checkout, payments, loyalty, and store locator.
• Write clean, well-tested TypeScript following our established coding standards, with automated checks (linting, formatting, architectural boundary rules) running on every commit.
• Connect the app to backend services and third-party tools: our ordering API, authentication, payment processors, fraud detection, feature flags, and analytics.
• Work with product managers, designers, and backend engineers to turn requirements into working software — joining sprint planning and reviews, implementing against Figma designs, aligning on API contracts.
• Review code from teammates and incorporate review feedback on your own pull requests; all PRs go through CI checks and peer review before merging (no direct pushes to main).
• Debug and fix issues on both iOS and Android using crash reporting tools, native logs, and device/simulator builds.
• Write and maintain tests — unit, component, performance (we track render and time-to-interactive budgets), and end-to-end flows tested on real devices via BrowserStack.
• Help keep our build and release pipelines healthy: automated builds, beta testing distributions, and production releases to the App Store and Google Play.
• Document your work — code comments, architecture decision records, and notes in our project management system.
• Participate in Agile ceremonies: standups, sprint planning, refinement, and retrospectives.
• Stay current with the React Native ecosystem and contribute to team-wide improvements, including our ongoing migration to the React Native New Architecture (better performance and native integration).

WHAT WE’RE LOOKING FOR

Required:

• 6–9 years of professional software engineering experience.
• Strong commercial experience building cross-platform mobile apps with React Native and TypeScript.
• Solid understanding of React Native architecture: state management (Redux), navigation, performance optimization, and local storage.
• Experience calling REST APIs and working with token-based authentication flows.
• Familiarity with the native side of React Native — iOS (Swift/Objective-C) and Android (Kotlin/Java) builds, native modules — or genuine enthusiasm to learn.
• Practical experience with mobile testing: unit tests, component tests, and end-to-end flows.
• Experience shipping apps to the App Store and/or Google Play.
• Clear communicator who works well in a collaborative, cross-functional team.
• Bachelor’s degree in Computer Science, Engineering, or a related field — or equivalent hands-on experience.

Nice to have:

• Payment integrations (Adyen, Apple Pay, Google Pay).
• Feature flag systems (e.g., LaunchDarkly).
• Mobile analytics or error tracking (Sentry, Adobe Experience Platform, Quantum Metric).
• CI/CD for mobile: GitHub Actions, Expo EAS, Fastlane, BrowserStack.
• Internationalization (i18n) and multi-language app support.
• Privacy and consent frameworks (e.g., OneTrust).
• SSL/certificate pinning for mobile API security.

HOW WE WORK

We use Agile delivery in two-week sprints, tracked in Azure DevOps. Design specs come from Figma. Architecture decisions and technical docs live alongside the code in the repository. We value code quality, thoughtful review, and incremental improvement over big-bang rewrites.

Pull requests go through automated CI checks (tests, linting, build validation) and at least one peer review before merging. We treat the CI pipeline as a quality gate, not a formality.