Heliacer developed a new JSON Block Definitions interface for the google/blockly repository, focusing on extensibility and backward compatibility with legacy block styles. Using TypeScript and the Blockly framework, Heliacer designed the interface to allow developers to define block structures in JSON, streamlining block creation and maintenance. The implementation included robust error handling and validation to ensure reliability when processing block definitions. Heliacer also created and updated unit tests to cover both the new interface and compatibility scenarios, ensuring comprehensive test coverage. The work demonstrated a solid understanding of interface design and careful attention to maintainability and future-proofing within Blockly.