Worked on the SatoshiPortal/bullbitcoin-mobile repository to enhance both build reliability and user transaction safety. Addressed build scripting challenges by updating Makefile logic in Dart and shell scripting, ensuring that build processes no longer fail when attempting to remove non-existent files. Improved the mobile send feature in Flutter by introducing input validation that disables the continue button unless the entered amount is greater than zero and within the wallet balance, preventing invalid transactions. These changes reduced operational risk, improved developer workflow, and strengthened user trust by making the application’s build and transaction flows more robust and maintainable for ongoing development.