Android PIN Payment Gateway

I need a developer who can wire the CBL mobile payment gateway into my existing Android app and make sure every transaction is confirmed by a simple PIN code entry. All payments will be initiated and completed on the device, so the flow has to cover token generation, hand-off to CBL’s API, callback handling, and clean error messaging for the user.

You may work in Kotlin or Java, but the final module must drop into an Android project running API 24+. I will supply the merchant keys, sandbox credentials, and UI guidelines.

Please observe standard PCI-DSS practices, encrypt every sensitive field in memory, and log only what is safe for debugging.

Acceptance criteria
• A reusable Android module (AAR or Gradle library) that exposes initialise(), charge(), and refund() methods
• Custom PIN screen (4–6 digits, client-side validation) that couples seamlessly with the gateway’s auth request
• Sample Activity demonstrating a successful payment and a handled failure state
• Brief setup guide and inline code comments

If you have completed similar mobile gateway integrations, especially with PIN-based verification, let me know—code samples or a quick demo APK would be ideal.