Johannes developed a Dynamic Tariff Provider for Octopus Energy Germany in the evcc-io/evcc repository, enabling dynamic electricity pricing data to be accessed via a GraphQL API. He designed and implemented authentication flows, rate fetching, and configuration parsing to support user-specific pricing information, laying the groundwork for cost-optimization workflows in EV charging. His approach emphasized modular backend development in Go, allowing for future expansion to additional German tariff providers. Throughout the month, Johannes focused on feature delivery, code quality, and reliability, demonstrating skills in API integration, GraphQL, and backend testing, with no major bugs reported during this period.