SDE Roadmap

Interview preparation

Same topics as the roadmap — now you have to say them out loud. Mark a question done when you can answer without notes.

Interview phase topics0%
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Tech Interview Handbook

Coding, behavioral, and system-design interview playbook.

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Behavioral interview questions

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Track this phase

Also mark the four interview topics (DSA / CS / Project / Behavioral) from the roadmap when you are ready.

DSA interviews

Two Sum / pair with given sum — hashmap vs two pointers.

Arrays

Coding interview prep LeetCode — Array tag

Kadane's algorithm (maximum subarray). Can you prove the invariant?

Arrays

LeetCode — Array tag

Inorder / preorder / postorder and level order. Iterative vs recursive.

Trees

LeetCode — Tree tag

Lowest common ancestor in a BST vs a binary tree.

Trees

LeetCode — Tree tag

Number of islands / connected components — BFS vs DFS.

Graphs

LeetCode — Graph tag

Detect a cycle in a directed graph (course schedule).

Graphs

LeetCode — Graph tag

Climbing stairs / house robber — identify the recurrence out loud.

DP

LeetCode — Dynamic Programming tag

0/1 knapsack or coin change. What is the dimension of the DP?

DP

LeetCode — Dynamic Programming tag

Search in a rotated sorted array.

Binary Search

LeetCode — Binary Search tag

Binary search on the answer (Koko eating bananas).

Binary Search

LeetCode — Binary Search tag

Longest substring without repeating characters.

Sliding Window

LeetCode — Sliding Window tag

Minimum window substring. When do you shrink the left pointer?

Sliding Window

LeetCode — Sliding Window tag

CS fundamentals

Process vs thread. Can two threads in a process crash each other?

OS

Process vs Thread

What is a deadlock? Give the four conditions.

OS

Deadlock in OS

Mutex vs semaphore.

OS

Operating Systems — GeeksforGeeks

Explain ACID with an ATM withdrawal example.

DBMS

ACID properties

What is an index? When would you not add one?

DBMS

Indexing in DBMS

Isolation levels and dirty vs phantom reads.

DBMS

PostgreSQL Transaction Isolation

TCP vs UDP. Give one product that should use each.

CN

TCP vs UDP

What happens when you type google.com in the browser?

CN

What happens when you type a URL

HTTPS vs HTTP. What does TLS give you?

CN

What is HTTPS?

Encapsulation vs abstraction, in one example.

OOP

OOPs Concepts in Java

Composition vs inheritance. When do you pick each?

OOP

OOPs Concepts in Java

Explain any two SOLID principles with code-level examples.

OOP

SOLID Principles

Project interview

Why did you choose this architecture?

Project

Why this database?

Project

What happens if traffic increases 10x?

Project

What was your hardest bug?

Project

How did you improve performance?

Project

Why did you choose this technology?

Project

Where are the single points of failure?

Project

How do you authenticate users, and where is the session stored?

Project

Behavioral

Tell me about yourself.

Behavioral

Behavioral interview questions

Why this company?

Behavioral

Behavioral interview questions

Tell me about your biggest challenge.

Behavioral

Behavioral interview questions

Tell me about a conflict with a teammate.

Behavioral

Behavioral interview questions

Tell me about a failure.

Behavioral

Behavioral interview questions

Tell me about a time you showed leadership.

Behavioral

Behavioral interview questions

Which project are you most proud of, and why?

Behavioral

Behavioral interview questions