What is DSA and Why do recruiters ask DSA questions during interviews?
What is DSA?
DSA is an abbreviation for Data Structures and Algorithms. It is also sometimes referred to as PSDS - Problem-Solving Data Structures. DSA is used to solve problems and teaches developers how to design efficient code. The amount of memory and time consumed by the code can be used to assess its quality.
The more efficient the code is, the less memory it consumes and the faster it operates.
Why is DSA important?
A person with good DSA skills will have better and more efficient ways to issue resolution than someone who is unfamiliar with DSA concepts.
DSA may not directly apply to your career, but it is the foundation of computer science. If you have mastered DSA, you will undoubtedly be a better software developer. As a result, it's best to learn it carefully at the start of your IT career.
How do companies use DSA?
Companies use DSA in mainly two ways -
- Online Screening
- Personal interviews
In both scenarios, you, as a candidate, must write code to address a DSA-based problem.
Websites such as HackerRank, LeetCode, and CodeForces provide enormous collections of issues ranging from easy to medium to challenging. Anyone can sign up for these websites and solve challenges by creating code in any primary programming language, honing their PSDS skills.
Many organizations utilize their websites to set interview questions. These websites have powerful evaluation tools for checking your programme for various test cases and plagiarism.
1. Online Screening
DSA is used by businesses to screen candidates. A corporation may receive 500 applications and must choose between 20 candidates.
DSA coding assessments are used to screen candidates objectively.
By doing so,
1. The organization spends 1-2 hours solving a problem on HackerRank and receiving automatic leaderboard performance data.
2. Applicants spend no more than 2 hours travelling to the next step of the interview.
Without doing so,
1. The company requests that all 500 applicants construct a project in 12 hours.
2. The organization must create automatic evaluations for this project, which will take their engineers 20+ hours to complete.
3. rejected applicants have squandered 12 hours of their valuable time.
How are coding assessments fair ?
1. The candidates' coding abilities are evaluated.
2. The difficulty level of the issues set determines the depth of DSA knowledge.
Yet, there are several drawbacks to this way of screening candidates.
Unless robust proctoring methods are employed, anyone can take the online test.
2. Problem Difficulty
The difficulty of the challenges increases steadily as the number of candidates grows.
This is because employers do not want all candidates to have the same score; instead, they require a stack rank.
As a result, online coding evaluations may become too complex, exceeding what is required for the job.
2. Personal Interviews
Other than coding aptitude and DSA knowledge, the personal interview rounds aim to test the candidate's following skills:
They assess your ability to ask the correct questions, come up with multiple answers, cover all elements of the problem, make the right trade-offs, and so on.
The ability to debug
The interview will also assess whether you can structurally debug the code when encountering problems.
In other words, firms typically look for the final output of the code they have developed during online examinations.
During personal interviews, the interviewer is more interested in your problem-solving approach.
In this round, well-prepared interviewers rarely ask common leetcode challenges.
They will provide increasingly realistic problems to you to see how you handle them.
Even if asked to tackle complex problems, interviewees are more interested in how you approach the problem than in the final result.
How effective are these interviews?
DSA interviews do a very fair estimation of your
- Cognitive abilities
- Problem-solving abilities
- Coding abilities
- Debugging skills
Debugging abilities are particularly evaluated during personal interviews.
PSDS has evolved into a filtering criterion for which everyone over-prepares.
Many firms end up asking some of the most common questions, and because they are common, if you have prepared for the exact same topic, you will be able to answer it.
In the process, the idea of evaluating the candidate's cognitive, problem-solving, and coding talents is gone.
Studying several significant 400+ leedcode problems can sometimes be enough to pass online screening rounds.
To address this, organizations continue to increase the level of difficulty of the questions so that they can distinguish between applicants who have prepared in advance by solving a large number of issues and those who have honestly solved the problem on the spot.
As a result, DSA interviews have become five times more challenging than what is required to become a successful software engineer.
How much DSA do you really need to study ?
- Implementation problems
- Level 1: Arrays, Strings, LinkedList, Simple implementation problems
- Level 2: Hash, Queue, Stack, Trees application
- Level 3: Graph, DP, Recursion
Practicing and expanding your knowledge in DSA will be essential for acing interviews.
Make sure to invest a significant amount of time in this before applying for jobs.
Thankfully, we at sysiit have professional subject matter experts who will teach you not just the subject but also will make your learning journey enjoyable with their decades of teaching experience and will go the extra mile to assist you in getting your dream job.
Have any questions about this article? Feel free to ask our Subject Matter Expert at 905-629-3000