User feedback is becoming an increasingly important source of information for requirements engineering, user interface design and software engineering in general. Nowadays, user feedback is largely available and easily accessible in social media, product forums or app stores. Over the last decade, research has shown that user feedback can help software teams: (a) better understand how users are actually using specific product features and components, (b) faster identify, reproduce and fix defects, and (b) get inspirations for improvements or new features. However, to tap the full potential of feedback, there are two main challenges that need to be solved. First, software vendors must cope with a large quantity of feedback data, which is hard to manage manually. Second, vendors must also cope with a varying quality of feedback as some items might be uninformative, repetitive or simply wrong. This chapter summarizes and pipelines various data mining, machine learning and natural language processing techniques, including recent Large Language Models, to cope with the quantity and quality challenges. We guide researchers and practitioners through implementing effective, actionable analysis of user feedback for software and requirements engineering.