Explore techniques and best practices for evolving protobuf contracts without breaking downstream callers in microservices architecture. Learn what constitutes a breaking change and discover tactical approaches to maintain service contract integrity. Dive into proto design patterns that minimize the need for API contract breaks. This 16-minute conference talk by Ryan Michela from Salesforce, presented at a CNCF event, covers topics such as semantic versioning, proto style, service contracts, and managing contract changes. Gain insights on cohesion, three-module layout, and multiple contract versions to improve microservices deployment and avoid lockstep deployments.