This course will focus on a few great ideas in theoretical computer science that power modern computing applications. We will cover both classical ideas in algorithm design and more contemporary ideas from optimization and their applications. We will also study new computation models, such as online learning and streaming algorithms, motivated by current large-scale applications. We will examine the role of randomness in algorithm design and theoretical computer science more generally. We will also cover modern topics, such as error-correcting codes and their role in reliable information transmission.