When you type a few characters into a search box and suggestions immediately appear, it is easy to assume that the application is simply filtering a list of strings. For a small dataset, that might actually be enough. But imagine a system containing millions of products, search queries, usernames, locations, commands, or other terms. Now … Read more
Imagine you are running a backend service that has thousands of tasks waiting to be processed. Some tasks are normal. Some are urgent. Some have been waiting for a long time. Some consume significantly more CPU than others. Now suppose your worker has capacity to process only one task at a time. Which task should … Read more
If you have worked on a backend application, chances are you have used a hash table even if you didn’t explicitly think about it. A Dictionary<TKey, TValue> in C# is a hash table. A cache backed by Redis relies heavily on key-based lookup. A database index is designed around the same broader idea: make finding … Read more
Arrays and strings are usually among the first topics we learn when starting with data structures and algorithms. At first, the problems seem straightforward: Then the problems start getting interesting. You are given a large array and asked to find a particular subarray. You need to process millions of events and identify activity within a … Read more