Marcos Souza developed and delivered Submerchant Information Handling and TaxIdentificationType support for the stone-payments/demo-sdk-android repository, focusing on enhancing payment processing and compliance for merchant onboarding. He upgraded the Android SDK to version 5.6.0.3 and aligned Gradle dependencies to v4.15.0, ensuring compatibility with modern Android development standards. Working primarily in Java and Kotlin, Marcos updated the sample application to reflect new submerchant tax identification features, preparing the codebase for expanded regulatory compliance and onboarding flexibility. His work demonstrated depth in Android development and SDK integration, prioritizing robust payment processing capabilities over bug fixes during this period.