Spring Boot is a widely used framework for Java web apps and micro-services. Optimizing its performance is crucial for handling heavy traffic and improving user experience. Key techniques include enabling Class Data Sharing (CDS) to speed up startup times, configuring threads in controllers and the database access layer, implementing caching to reduce database load, utilizing batch processing for large data sets, enabling lazy loading to defer unnecessary data fetching, and compressing or minifying payloads to enhance performance.