Big Tech - Coding Interviews

The coding interview process at MAANG companies has become both a dream and a nightmare for many aspiring engineers. Before writing this post, I had numerous discussions with friends working at such companies. In this guide, I will cover preparation, LeetCode, optimal solutions, overcoming struggles, and other essential strategies to succeed.

Don't just read this post—act on it! If you don’t, this could be you in the interview 👇🏻

Coding Rounds

During this stage, your skills beyond algorithms will be tested. Interviewers assess multiple competencies, including:

• Technical Competence: Writing clean, efficient, and maintainable code.
• Problem-Solving: Breaking down complex problems into manageable parts and finding optimal solutions.
• Ability to Work Under Pressure: Handling time constraints and high-pressure scenarios.
• Communication Skills: Clearly articulating thoughts, explaining reasoning, and responding effectively to feedback.
• High Standards: The best performers across these categories receive job offers because top tech firms seek only the best candidates.

Your Recruiter is Your Best Friend

It might sound exaggerated, but from my personal experience, your recruiter is there to help you succeed. They’re not your enemy; they want you to pass all interview stages, land the job, and enjoy free meals at your dream company.

If you have questions, don’t hesitate to ask. Recruiters can provide preparation resources and even connect you with people in the role you're applying for. Always be proactive in seeking guidance.

The Actual Coding Round

Feeling nervous? Butterflies in your stomach? Brain stuck on HashMap? Congrats, it's just the beginning.

You will typically have 45 minutes to solve problems. Sometimes, the interviewer will start with an easy question to warm you up. However, you must efficiently manage time, ask clarifying questions, propose solutions, and write code within the given timeframe.

Example Problem:

Read a file and calculate the frequency of each word in it.

Sounds simple, right? But panic can take over, leading to random thoughts:

DP, HashMap, Linked List, RAM, Directed Graph, MOM, WHY AM I SO DUMB?!

Instead of spiraling, stay calm and prepare yourself properly.

Confirm Your Understanding

Interviewers won’t just throw you into a problem without some ambiguity. It’s your job to ask clarifying questions:

• “What format is the input file? JSON or CSV?” Assumptions don’t help—get confirmation.
• “How large is the file? Can it fit into memory?” Handling a 30GB file line-by-line requires different logic than reading a small file at once.
• “Are there Unicode characters?” A seemingly minor detail that can cause major issues if overlooked.
• “What’s the expected output format?” Are you returning a dictionary, writing to a file, or outputting JSON?

Writing down input constraints during the discussion helps avoid mistakes later.

Check Input Bounds

Understanding input and output boundaries is crucial. If you're working with an integer array, ask:

• Is the array sorted?
• Can it contain negative numbers?
• Can it be empty?
• Are values signed or unsigned integers?

These questions demonstrate analytical thinking and prevent unnecessary errors.

Think Out Loud

Verbalizing your thought process is essential. It might feel awkward, but interviewers want insight into your approach. If you go silent and start writing code immediately, they have no idea what you're thinking.

Discuss Potential Limitations

Every solution has trade-offs. If you're using generators to handle large files efficiently, mention that they don’t allow backtracking. Showing awareness of such limitations highlights your depth of understanding.

Start Coding

Once your interviewer gives you the thumbs-up on your solution, it's time to write some real code! Here's what to expect:

• You'll usually get a basic text editor - no fancy colors, no auto-complete, no error highlighting. It's like writing on a digital napkin! 😅
• Pick a language you're super comfortable with. If you know Java like the back of your hand but only learned Python last week, stick with Java! This is not the time to show off new skills.
• Create helper functions when they make sense. For example, if you're solving a problem with arrays, maybe write a separate function that handles the array sorting or searching part. This keeps your main code clean and shows you think in organized chunks.
• Use clear variable names like customerCount instead of just c. Add helpful comments for tricky parts. Your interviewer should be able to read your code like a good book - easy to follow and understand!

Pro Tip: Clean, readable code says a lot about how you think. Messy code = messy thinking. Clean code = clear thinking. Which impression do you want to make?

Preparation Process

Before diving into LeetCode problems, make sure you have a solid foundation in data structures and algorithms. You should be able to code up common ones (like sorting algorithms or a linked list) in 5-10 minutes without breaking a sweat.

Here's how to build that foundation:

• Focus on truly understanding concepts, not just memorizing solutions. Ask yourself: "Could I explain this to a 10-year-old?"
• When you look at example solutions, analyze each line of code like a detective. What is it doing? Why is it necessary? Could it be improved?
• If you struggle with a problem, don't just move on. Revisit and re-implement solutions until they feel natural, like tying your shoes.
• Space out your practice - try a problem again after a few days to make sure the solution stuck in your brain.

Memorization? Really?

Yes, sometimes memorizing standard solutions is actually smart! Would you criticize a chef for memorizing a classic recipe? Or a musician for memorizing chord progressions?

Knowing common patterns by heart (like two-pointer technique or binary search) saves precious interview time for the unique parts of the problem. It's not "cheating" - it's being efficient with your brain power!

If this post was helpful, don't forget to share it with friends who are preparing for their own tech interviews. Good luck, and may the algorithms be ever in your favor! 🍀

© References:

• Inspired by Shafiqa Iqbal’s Medium post
• Advice from friends
• Personal experience