Follow a structured SDE interview preparation roadmap: spend the first 6–8 weeks on core DSA topics like arrays, strings, hashing, linked lists, trees, graphs and dynamic programming, then move to CS fundamentals (OS, DBMS, OOPs, computer networks), system design basics and behavioural questions in the final month. Aim for 150–250 quality problems solved by pattern rather than by memorising solutions, and keep the last 2–3 weeks for revision plus a few mock interviews under real time pressure.

Focus on depth over breadth: SDE-2 panels test system design, LLD, scalability trade-offs and mature problem-solving on top of coding. DSA interview questions and answers for experienced candidates usually lean towards complex graph and DP variations and optimisation discussions rather than textbook definitions. Block fixed study hours around your job, be ready to justify the technical decisions in your own projects, and practise system design out loud with a peer or mentor.

Pick one language and get genuinely fluent in it, then go topic by topic: arrays and hashing, two pointers, sliding window, binary search, stacks and queues, linked lists, trees, heaps, backtracking, graphs and dynamic programming. Solve problems by recognising patterns, always state time and space complexity, and revisit problems you failed after a few days instead of only moving forward. Consistent 1.5–2 hours daily beats weekend binge-solving.

Use a repeatable framework: restate the problem, ask clarifying questions about input size and edge cases, state the brute-force approach, and then optimise while explaining your reasoning out loud. Interviewers evaluate how you think, so narrate your trade-offs, confirm the complexity before coding, dry-run your solution on an example, and stay open to hints. A wrong attempt with clear communication usually scores better than silence.

Fresher rounds typically cover arrays and strings (reversal, anagrams, subarray sums), hashing problems, linked list operations, stack and queue applications, binary search, basic tree traversals, recursion and easy-to-medium graph or DP questions. Instead of mugging up answers, learn the underlying pattern behind each question, because interviewers modify the statement to check whether you truly understand it. Explaining your approach clearly matters as much as writing working code.

Most product companies, including Amazon, allow you to code in any mainstream language, so depth in one language matters more than which language you pick. That said, DSA interview questions in Java are popular among Indian aspirants because Java's built-in collections like HashMap and PriorityQueue make implementations fast during interviews. Use whichever language you can write bug-free code in under pressure, and avoid switching languages weeks before your interviews.

DSA interview questions on GeeksforGeeks are a strong starting point, especially for company-wise previously asked questions and standard patterns, but they are rarely enough on their own. Interviewers now frame variations that sheet-based preparation may not cover, so combine it with LeetCode-style pattern practice, system design for experienced roles, and mock interviews. Use GFG to understand how a problem is expected to be solved, then re-solve it yourself without looking at the solution.

For SDE interview preparation on GitHub, look for well-maintained repositories that curate topic-wise DSA sheets, company-wise question lists, system design notes and interview experience write-ups. Pick one curated list and complete it fully instead of hopping between multiple sheets, and always re-implement solutions yourself rather than just reading them. Many of these repositories also include solutions in multiple languages, which helps you compare approaches for the same problem.

If you look up the mock interview meaning, it simply refers to a simulated interview conducted under real conditions — a timed coding round, a system design discussion or a behavioural round with someone playing the interviewer. It exposes gaps that solo preparation hides, such as how you explain your thinking, handle follow-up questions and manage time pressure. Many candidates who know the material still fail their first interviews simply because they never rehearsed in a realistic setting.

Very useful — a mock interview for freshers works mainly as pressure training. Freshers often know the theory but freeze when a stranger probes their solution or when the clock is running. A mock helps you practise thinking aloud, recovering when stuck, and structuring answers to questions like "tell me about yourself" and project explanations, so that your first real interview is not your first-ever attempt.

Free options for mock interview practice online for free include peer mocks with friends or seniors, community groups where members interview each other, and AI tools that ask questions and critique your responses. Free mocks are great for building volume, but the quality of feedback depends on who is playing the interviewer — a peer may miss things an experienced engineer would catch. So use free mocks for regular practice and add one or two mocks with an experienced professional closer to your actual interview dates for sharper feedback.

A mock interview with AI is excellent for daily reps — it can generate unlimited questions, force you to think aloud and give instant feedback. What it cannot fully replicate is a human interviewer's unpredictability: probing follow-ups, subtle reactions and nuanced judgment of your communication. The best approach is to use AI mocks for frequent, low-stakes practice and supplement them with a few mocks conducted by experienced engineers under realistic conditions.

Practice under exam conditions: set a timer, avoid hints and auto-complete, and speak your solution out loud while coding, because that mirrors the actual interview. The strongest way to practice interview questions is spaced repetition — redo failed problems after 3–4 days, keep an error log of patterns you miss, and rotate topics weekly so nothing goes stale. Ending each week with a mock interview keeps both your recall and your communication sharp under pressure.

It depends on your current level and discipline. An SDE interview preparation course is worth it when you need structure, personalised feedback and accountability — for example, if you keep postponing preparation, get stuck without direction, or keep getting rejected at the same stage. Self-study works if you are consistent and can honestly evaluate yourself. Whatever you choose, judge any program on the mentor's real interview experience, one-on-one feedback and mock interview quality, not on the number of recorded lectures.

SDE interview prep for Amazon needs two parallel tracks: strong DSA — usually two coding rounds with medium-level problems — and deep preparation on Amazon's Leadership Principles, because behavioural answers are evaluated almost as strictly as coding. Prepare 8–10 real stories from your projects or work in the STAR format, since the Bar Raiser round specifically probes ownership, data and depth in your examples. For SDE-2 roles, add system design and LLD practice to this plan.