In this module, you’ll learn about what factors can cause a machine or program to act slowly. You’ll dive into ways of addressing slowness by identifying the bottleneck that might be causing the slowness. You’ll learn about tools to identify which resources are being exhausted, including iotop, iftop, and activity monitor in MacOS. Next, you’ll learn how computers use resources, and understand the differences between CPU, RAM, and cache in order to help you find the possible causes for slowness in our machines or scripts.Next up, you’ll learn how to write efficient code, then explore profilers to help you identify where your code is spending most of its time. Next, you’ll dive into data structures and understand which ones are right for you to use. These include lists, tuples, dictionaries, sets, and expensive loops. Then, you’ll dive into complex slowness problems and how utilizing concurrency and adding a caching service can improve the execution of your code. Finally, you’ll understand how using threads can make the execution of your code much quicker.

In this module, you’ll get introduced to the age old question, “Why has my program crashed?” You’ll learn how to troubleshoot system crashes and application crashes, what tools can be used to help identify the cause of the crash, and what log files to look at in order to find what might have gone wrong. Next, you’ll dive into investigating why code crashes, and what you can do to prevent that from happening. Then, you’ll explore what happens when an unhandled error occurs and throws an exception. You’ll learn about several debugging techniques, which will help you identify these errors and exceptions. Finally, you’ll explore the concept of handling crashes and incidents at a much larger scale. You’ll delve into a scenario where a large eCommerce site will throw an error 20% of the time. Once that issue has been fixed, you’ll understand the importance of communication and documentation during these incidents, and how writing a post mortem can prevent issues from happening again.

In this module, you’ll learn how to manage your applications. You’ll dive into some common issues that may cause your application to crash. You’ll also understand what memory leaks are, and how to troubleshoot and prevent them. Up next, you’ll run down managing disk space; you’ll see some scenarios of how this happens and how to identify what process or application is taking up all your disk space. Then, you'll learn what network saturation is, how it can be caused, and some useful tools and techniques to solve a network saturation problem. Next, we’ll shift from managing applications to managing your time. You’ll get tips on how to prioritize tasks, estimate how long a particular task will take before finishing, and communicate expectations when dealing with important tasks. The final lesson delves into how to deal with hard and complex problems by breaking it down into small, digestible chunks while keeping your eyes on a clear goal. You’ll learn that using proactive approaches, like continuous integration, can help you with future issues that might come up. You’ll also explore how to plan for future resource usage by making good use of monitoring.