Developed foundational card-present payment capabilities for Shopify by implementing default configuration management within the extensions-templates repository and introducing schema-driven validation for payments app extensions in the Shopify/cli repository. Leveraged TypeScript, JavaScript, and schema definition techniques to enable predictable configuration and safer deployments of card-present payment features. The work established a validated extension pathway, ensuring required fields are enforced and deployment mapping is accurate, which reduces misconfigurations and accelerates merchant onboarding. Collaboration across repositories strengthened the integration between extension templates and CLI tooling, resulting in end-to-end readiness for production deployment of card-present payments using robust API integration and configuration management practices.