If you’re preparing for FAANG interviews in 2025 (like me right now 👀), you’ve probably asked yourself:
“Why the heck are they still asking me about reversing a linked list when nobody in real life codes that from scratch?”
Fair question. But the answer is deeper than just “because tradition.” Let’s break it down.
🚀 1. DSA shows how you think under pressure
At FAANG-level interviews, you’re not being hired to write just code. You’re being hired to:
- Break down a vague problem
- Find multiple ways to solve it
- Pick the best one under constraints
DSA problems are the fastest way to test this.
For example:
- Two Sum problem – Do you brute force, or do you immediately see the hashmap optimization?
- Graph traversal – Do you BFS or DFS? Can you explain why?
It’s less about solving Two Sum itself, more about showing that your brain defaults to “optimize and scale.”
🏗️ 2. Real-world systems secretly run on DSA
Most devs don’t directly implement heaps, tries, or segment trees at work.
But… the systems you’re building on top of do.
Examples:
- Google Search → Tries, inverted indexes, heaps.
- Netflix Recommendations → Graph algorithms, dynamic programming tricks.
- Databases (MySQL, MongoDB) → B-Trees, Hash Indexes.
- Load balancers → Queues, hashing, priority scheduling.
If you understand the DSA under the hood, you’ll design better systems because you know the trade-offs.
⏱️ 3. Interview Time is Limited
A full system design interview needs 45–60 minutes.
So how do they test raw problem-solving in a short span?
→ Throw you a DSA problem.
In 20–30 minutes, they can see:
- Can you handle edge cases?
- Do you write clean code under pressure?
- Do you think about time and space complexity?
It’s basically the unit test for your brain.
💡 4. Senior Engineers Still Use DSA Thinking
At SDE-3+ level, you’re not coding linked lists every day.
But you are doing:
- “How do we reduce query time from O(n) to O(log n)?”
- “Should we shard this DB by hash or range?”
- “Can we cache results in a trie-like structure for autocomplete?”
That’s just DSA thinking applied to real-world scale.
🏆 5. FAANG Needs a Consistent Global Filter
Imagine trying to interview thousands of candidates across the world.
DSA provides a universal, fair filter:
- Doesn’t matter which framework you’ve used.
- Doesn’t matter if you were a freelancer, startup dev, or from a Tier-3 college.
- Everyone can be judged on the same foundation: problem-solving.
🔑 Takeaway
In 2025, yes — we have AI copilots, LLMs, auto-complete everything.
But DSA is still the quickest way for FAANG to test your brain’s OS.
If you’re prepping (like me), don’t just grind LeetCode blindly.
👉 Learn why an approach works, and how it connects to real-world systems.
That’s the difference between a LeetCode grinder and an engineer FAANG wants to pay 50LPA+ for.
✍️ Personal Note
I’m currently preparing for 50LPA+ SDE roles myself, and this blog is where I’ll share everything I learn along the way — from DSA to System Design to backend engineering. Writing about it helps me understand things deeper, and hopefully, it helps you too if you’re on the same journey.
Stay tuned — more blogs coming soon 🚀