From Playlists to Search Engines: The Everyday Power of Data Structures and Algorithms

By: Emma Dafoe

If you’ve ever taken a computer science class, you’ve likely heard of data structures and algorithms, or DSA for short. DSAs are often working behind the scenes in systems that we use every single day. Before we dive into the countless real-world applications of DSAs, let’s review what they are. DSAs, as the name implies, combine two systems: data structures and algorithms.  

Data structures are methods of organizing data.⁷ If you had a bunch of information about your family history, for example, you could use a family tree as the data structure to organize it all and make it easier to interpret.⁷ Within databases, data structures determine how data is organized, stored, and accessed,⁶ and, if you’re listening to music as you read this article, you’re benefiting from the data structures used to make playlists.³  

Figure 1: Family Tree as a Data Structure (Image Credits: W³ Schools⁷ ).

Algorithms, on the other hand, are instructions on how to solve a problem or achieve a goal.⁷ For instance, following a recipe is an algorithm with the goal of baking a cake.⁷ Algorithms are used in e-commerce to sort product listings⁴ and in search engines to find web pages that match the question asked,⁴ to name a few examples.  

While both components are powerful on their own, data structures are more useful with algorithms that can manipulate them, and algorithms need data to work with.⁷ This symbiotic relationship allows us to efficiently organize data and solve specific problems.^1,7 When data structures and algorithms combine, the applications are innumerable. In machine learning and artificial intelligence, algorithms are essential for pattern recognition, learning, and decision-making, while data structures allow for the storage and processing of large amounts of data.⁴ You’ve probably heard of the “Instagram algorithm” that determines which posts you see. This is actually a collection of algorithms that work together, looking at the posts you like, your interaction history, information about the post, and more,⁵ to present you with posts you’re likely to enjoy. Given the large amount of data contained within a social media network, data structures are essential to organize it so that algorithms can assess it and use it to solve problems or achieve goals. DSAs are also used in databases, video games, GPS systems, cryptography, and so much more.² You can take your knowledge of DSAs and apply it to almost every area of software development.²  

So, the next time you're staring bleary-eyed at countless lines of code, searching for the single comma that’s causing everything to break, rest assured that what you’re learning is extremely important and largely transferable to many different areas of technology.  

Sources: 

1. Geeks for Geeks. DSA Tutorial - Learn Data Structures and Algorithms. https://www.geeksforgeeks.org/dsa/dsa-tutorial-learn-data-structures-and-algorithms/.  

2. Geeks for Geeks. Why Data Structures and Algorithms Are Important to Learn? https://www.geeksforgeeks.org/dsa/why-data-structures-and-algorithms-are-important-to-learn/.  

3. Medium. From Beats to Nodes: Building Dynamic Playlists with Linked Lists. https://medium.com/@jahnavivetukuri/from-beats-to-nodes-building-dynamic-playlists-with-linked-lists-6d4a0db12a96.  

4. Medium. Real-world Applications of Data Structures and Algorithms. https://medium.com/@beyond_verse/real-world-applications-of-data-structures-and-algorithms-364ded5bf65c.  

5. Mosseri, A. Shedding More Light on How Instagram Works. Instagram, June 08, 2021. https://about.instagram.com/blog/announcements/shedding-more-light-on-how-instagram-works  

6. PingCAP. SQL Data Structures Explained. https://www.pingcap.com/article/sql-data-structures-explained/.  

7. W³ Schools. Introduction to Data Structures and Algorithms. https://www.w3schools.com/dsa/dsa_intro.php.