Flutter SDK Engineer: Dart, Auth & REST for Mobile

Anythink; United States; Remote; USD 120,000 - 180,000; Part time

Job summary

Anythink is seeking a contract backend role to create a Flutter-friendly Dart SDK for our REST APIs. You will deliver authentication helpers, file storage support, and example apps, with mobile-focused docs and customer integration work.

You will publish an idiomatic Dart package to pub.dev and ensure smooth Flutter integration across iOS/Android deployments. This is a frontend-friendly backend tooling role, focused on developer ergonomics.

Qualifications

• Production Flutter and Dart experience with apps released to App Store or Google Play.
• Experience integrating REST APIs from Flutter using http or Dio.
• Strong understanding of JSON serialization and asynchronous Dart patterns (Futures/Streams).
• Experience publishing or maintaining a Dart package on pub.dev.

Responsibilities

• Develop and maintain a Flutter SDK package that wraps platform REST APIs.
• Implement authentication helpers for JWT handling, session refresh, and OAuth flows.
• Provide Flutter support for file uploads, downloads, and storage management.
• Build realistic example apps demonstrating common integration patterns.
• Write setup guides and documentation for mobile developers.
• Contribute to customer projects that integrate the platform with Flutter applications.

Skills

Flutter

Dart

REST APIs

JSON serialization

Async Dart (Futures/Streams)

Tools

http package

Dio package

pub.dev publishing

fastlane

Job description

Anythink is seeking a contract backend role to create a Flutter-friendly Dart SDK for our REST APIs. You will deliver authentication helpers, file storage support, and example apps, with mobile-focused docs and customer integration work.

You will publish an idiomatic Dart package to pub.dev and ensure smooth Flutter integration across iOS/Android deployments. This is a frontend-friendly backend tooling role, focused on developer ergonomics.