Systems like Hadoop, Spark, Kafka, Impala, and Tensorflow have made it easier than ever for enterprises to create or migrate apps to the big data stack. Thousands of apps are being generated every day in the form of ETL and modeling pipelines, business intelligence and data cubes, deep machine learning, graph analytics, and real-time data streaming. However, the task of reliably operationalizing these big data apps involves many pain points. Developers may not have the experience in distributed systems to tune apps for efficiency and performance. Diagnosing failures or unpredictable performance of apps can be a laborious process that involves multiple people. Apps may get stuck or steal resources and cause mission-critical apps to miss SLAs. This talk with introduce the audience to these problems and their common causes. We will describe best practices to find and fix these problems quickly, as well as prevent such problems from happening in the first place.