Timing is everything. If a system does not respond in a timely manner then: at best, its value is greatly diminished; and at worst, it is effectively unavailable. Reactive systems need to meet predictable response time guarantees regardless of load or datasets size, even in the presence of burst traffic and partial failure conditions.

In this talk we will explore what is means to be responsive and the fundamental design patterns required to meet predictable response time guarantees. Queueing theory, Little's Law, Amdahl's Law, Universal Scalability Law - we'll cover the good bits. Then we'll explore algorithms that work with these laws to deliver timely responses from our applications no matter what gets thrown at them.