Design proposals are at the heart of how open source projects evolve, and OpenTelemetry is no exception. This panel brings together contributors with a range of roles in the project, including governance and technical committee members, specification sponsors, and implementation maintainers. We will explore how OpenTelemetry handles design through OTEPs (OpenTelemetry Enhancement Proposals), semantic convention proposals, and new feature additions, both in the specification and implementations. The discussion will cover prototyping, design review, community engagement, and communicating changes. While focused on OpenTelemetry, many of the lessons and challenges such as building consensus, maintaining momentum, and balancing innovation with stability apply broadly to any open source project.