What algorithms should you know as a software developer?

Honestly, in the vast majority of cases, you don't need to write your own sorting algorithms, because the standard library is probably faster. The only time I *have*, it was because I wanted a stable sort in C#, while List.Sort in C# is unstable. That said, it's still worth it to know a few, both because you never know when you'll wind up in a weird position where you need to write one, and because they're frequently good algorithms for understanding concepts. (e.g. merge sort is basically the archetypical recursive algorithm)

Sorting algorithms are critical in software development. Seeing items by price on Walmart, finding book titles by putting them in alphabetical order, or organizing your contact book by last name all use sorting algorithms under the hood. Know these inside out, because you'll need them!

While you dont write your own sorting algoritms when you are developing the application, it is very important to know and understand how different algorithms work. It is critical to understand the time and space complexity of different algorithms as it ultimately contribute to the performance and reliability of your application.

If you have a programming application, one way or the other the sorting will be used with or without our knowledge, most of the programming languages have utility functions that handle the sorting, but knowing how it works helps in a few customization scenarios.

Don’t waste time building your own sorting algorithms. The best of the best algorithms are built in and available via .sort() or “ORDER BY”. Spend time optimizing system performance in other ways.

"Just Google it!" Well, under the hood, Google uses a searching algorithm to find what you're looking for from billions of potential search results in a fraction of a second. Imagine if Google had to look through every webpage to find what you needed...you'd be here for a long time. Thank the power of searching algorithms for being able to search for an example of binary search in seconds.

It's important to point out that binary search requires a sorted collection that's quick to access by index. Also, hashsets and hashmaps use search algorithms that aren't either linear or binary, and are among the most efficient algorithms for storing and retrieving data.

Linear search can be simplest form but could take O(n) time space. If we have a sorted input binary search can perform better in Logarithm time O(log(n) )complexity.

From a search algorithm perspective it can be very useful to know the “Nested set model”. You can google the term in order to go deep into theory and/or technical detail for real implementation of this search model.

In Java, we have default hashcode method which is the simpler example of hashing algorithm. It can be override with custom implementation. In case we need to use employee object as a key in a Map, we can define hashcode on a unique field to have minimal collisions optimizing the performance.

Hashing converts variable data in length, size, and type into a small (256-bit) Unique ID optimized for fast key-value pair lookups. Also used to verify file contents have not been changed by bad actors.

Are recursive algorithms a must-know? Yes and No Yes because it’s essentially the backbone of some major algorithm concepts like Dynamic Programming, most Graph algorithms and also linked list operations. But would I use it in real time software? Not happily. It’s usually not very time optimized. Besides it also creates a stack in the heap memory and there can be some side effects that might break the system especially when there are concepts like concurrency involved.

Think of recursive algorithms as the Swiss Army knives of programming! Not only are they super handy for solving problems that can be broken down into smaller, bite-sized pieces, but they also teach us a way to think that's incredibly useful in real life. Just like how fractal patterns appear in nature and organizations, recursion helps us understand systems that have multiple layers. So, when you get the hang of recursion, you're not just learning to code better—you're also boosting your problem-solving skills in a way that's applicable far beyond the keyboard. It's a win-win!

In industry, while it’s important to understand how these algorithms work, they’re usually implemented for you. So make sure you brush up on them, but don’t fret too much!

95% of projects don't have the need to know or do any complex algorithms, only basic algorithms are needed. And most of the time the specific programming language provides the necessary functions that does the job. An example: Instead of building our own sorting algorithm, we can just use the built in sorting function that a certain programming language provides.