Even seasoned engineers can encounter unexpected challenges when building with Apache Flink, often leading to performance bottlenecks or stability issues. This session confronts three critical, yet common, mistakes that frequently trip up Flink users and significantly impact pipeline health. Attendees will learn how to effectively navigate Kafka connector migration rules to prevent uncontrolled state growth, optimize serialization to eliminate throughput-sapping Kryo fallbacks, and implement strategies for even load distribution across their Flink clusters. The talk offers practical, actionable insights, empowering developers to avoid these pitfalls and build truly robust, high-performance Flink applications.