Applying for a software engineering job can mean you will be asked all sorts of questions. During the initial interview, the questions will probably be pretty straightforward, such as ‘Tell us about a project you successfully completed’ – use our Interview like a STAR post to prepare to answer those. Once you clear the first step of interviewing, the next tier is usually a coding and/or system design interview, as they are common and fairly standard in the industry at the moment. Preparing for coding interviews can be nerve-wracking as there is a lot of much to keep in mind. To beat other candidates, you need to know what to expect and be fully prepared for the challenges. We’ve got you covered—with these tips, you will ace any coding interview!
Pick your language
As most companies will allow you to code in the language of your choice, make sure to use the language you are most familiar and comfortable with. Remember, that the coding interview is all about getting something working, ASAP. A tip from a candidate, who received offers from Google, Meta, and Airbnb: “Personally, Python is my choice for coding algorithms during interviews. It is succinct and has a massive library of functions and data structures. One of the top reasons I recommend Python is that it uses consistent APIs that operate on different data structures, such as len(), for … in … and slicing notation on sequences (strings, lists, and tuples). You can achieve a lot with minimal syntax in Python”. Great piece of advice, but again – use the language of YOUR preference to maximize your chance to succeed.
Know your fundamentals
First, the absolute must-haves, in order:
- Trees (especially Binary Search Trees)
- Big O Notation
- Hash Tables
- Object-Oriented Design/System Design
- Algorithms: Breadth First Search/Depth First Search, Binary Search, Merge Sort and Quick Sort
You are almost guaranteed to have questions related to these topics, so make sure you refresh your knowledge. Understanding how to write more efficient algorithms and why they’re more efficient is helpful at every level!
Master through practice
There are a few sites where you can practice for online coding tests. LeetCode is the most well-known. Here you can search for topics by keyword and sort the problems by difficulty level. A great advantage is that the system supports numerous languages – from C and C++ to Kotlin, Python, and JavaScript. You can write and run your code for the solution in the editor window, and can supply any test cases you desire. In LeetCode you will be able to see the runtime in milliseconds and memory in megabytes for each of your solutions. This lets you compare different ways of solving a problem against yourself, which leads you in the direction of thinking about how to program more efficiently in general.
Another platform to test your coding skills is Codility. Here you can refresh your knowledge about Prefix Sums, Sorting, Searching, Stacks and Queues, etc. The system is straightforward to use, and it also analyzes your submitted code cautiously, providing you with a detailed report regarding the time and space complexity of your code.
Be consistent
The problems you can expect to face in your coding interview can usually be solved many ways. To guide and structure your thinking, you would want to use a consistent answer framework – we find the Amazon approach quite useful. As it suggests, break down the problem into manageable steps and tackle them in a logical order. In short, the approach is as follows:
- Clarify – Explore the edges of the problem.
- Plan – List potential solution approaches, pick the one that is the most appropriate, and lay out the high-level steps to get to it.
- Implement – Now, write that code! Try to write clearly, structure the code well, consider boundary conditions or empty inputs, etc. Make your code modular and eliminate duplicate code. If you realize you’ve forgotten an important function, simply go back and insert it.
- Test & optimize – Utilize your assessment time wisely , so you’ll have enough time left to validate your code, giving you a better chance at success. Additionally, testing is an essential skill for employers to measure in an interview. Not only do software engineers write unit tests nearly every day on the job, but if you can write good unit tests, you probably have a strong understanding of what your code is trying to do.
Finally, a positive mindset and good physical health are of utmost importance when it comes to performing at your top level. So, rest well the night before your interview, do not overthink and approach the coding interview as an opportunity for growth – regardless of its outcome.
Best of luck and may the odds be ever in your favor!
