String Hashing and Rabin-Karp: Pattern Matching for Interviews
Learn string hashing and Rabin-Karp pattern matching for coding interviews with a clear rolling hash walkthrough and collision rules.
3 min read
The DSA Tracker Journal
Prep smarter, not longer.
The DSA Tracker Journal is a free blog on DSA interview prep: strategy, sheet comparisons and role-based roadmaps, written by the developer behind the tracker that reorders 370 curated problems around the role you are actually preparing for.
Dijkstra vs BFS vs Bellman-Ford
Learn how to choose between Dijkstra, BFS, Bellman-Ford, and 0-1 BFS for coding interviews with concrete rules and a worked example.
4 min read
Mock Interview Practice for DSA
Stop solving problems in silence. To master DSA interviews, you must explain your logic out loud while coding, forcing your brain to bridge the gap.
3 min read
DP on Grids: Unique Paths, Minimum Path Sum and Obstacles
Master grid dynamic programming by focusing on state transitions derived from allowed moves rather than memorizing patterns for unique paths or path sums.
3 min read
How to Use Hashing and Merkle Trees for Secure Web3 Interviews
Web3 interviews prioritize smart contract security and cryptography over standard DSA. Focus on Merkle trees and hashing to pass technical screenings.
3 min read
Sliding Window Maximum and the Monotonic Deque
Master the sliding window maximum using a monotonic deque on DSA Tracker. Learn how indices enter and leave once for optimal linear time.
3 min read
Stack vs Queue vs Deque: Which Data Structure a Problem Wants
Learn how to choose between stack, queue, and deque for coding interviews by matching problem shapes like brackets, BFS, and sliding windows.
4 min read
How to Stay Calm When You Get Stuck in a Coding Interview
Learn how to stay calm during coding interviews by using brute force, smaller examples, and clear communication to solve problems when you feel stuck.
3 min read
How to Validate Insert Delete and Search Binary Search Trees
Master Binary Search Trees by focusing on the inorder traversal property. Learn to validate, insert, delete, and find the Kth smallest element efficiently.
3 min read
Game Studio Rounds: Pathfinding, Grids and Graph Questions
Learn if game studios ask DSA questions in interviews, which graph and grid topics matter, and why C++ and engine profiling matter more.
3 min read
Arrays vs Linked Lists: What Interviewers Expect You to Know
Master arrays vs linked lists for Indian tech placements by learning exact memory layouts, amortised growth, and cache behaviour.
3 min read
Mastering Matrix Traversal and Search in Interviews
Master matrix interview questions on DSA Tracker by learning index bookkeeping tricks for spiral, rotate, and search 2D grid problems.
3 min read
Online Assessment vs Live Coding Round: How to Prepare for Each
Master placement preparation by learning how to tackle timed online assessments and live coding interviews with distinct strategies.
3 min read
Kadane's Algorithm Explained: Maximum Subarray and Its Variations
Learn Kadane's algorithm for maximum subarray and its variations with step by step reasoning, code logic, and handling all negative arrays.
4 min read
Embedded Systems Rounds: Bit Tricks, Pointers and Ring Buffers
Discover whether embedded systems interviews test DSA, which C pointers and bit manipulation topics matter, and how to master ring buffers.
3 min read
Bit Manipulation for Coding Interviews: The Tricks Worth Knowing
Master the essential bit manipulation tricks for coding interviews, from finding single numbers with XOR to counting set bits and building bitmasks.
3 min read
Greedy vs Dynamic Programming: How to Tell Which One a Problem Needs
Learn how to choose between greedy algorithms and dynamic programming for coding interviews using the exchange argument and counterexamples.
3 min read
How to Test Your Own Code in a Coding Interview
Learn how to test your own code in coding interviews by dry running normal, edge, and boundary cases before submitting your solution.
2 min read
0/1 Knapsack Pattern: The DP Behind Subset Sum and Target Sum
Master the 0/1 knapsack pattern for coding interviews on DSA Tracker with a clear guide from recursion to 1D space optimisation.
3 min read
Merge Intervals Pattern: Meeting Rooms, Insert Interval and More
Master the merge intervals pattern for coding interviews with a sort-then-sweep approach, clear examples, and practical placement prep tips.
3 min read
HashMap vs TreeMap vs Sorting: Choosing the Right Tool in DSA
Stop guessing between HashMap, TreeMap, and sorting in coding interviews. Learn exact lookup costs, ordered iteration, and memory trade-offs.
4 min read
What to Do in the First 5 Minutes of a Coding Interview
Master the first five minutes of a coding interview with exact questions, edge cases, and function signatures to write cleaner code.
3 min read
Dynamic Programming on Strings
Master 2D dynamic programming on strings for coding interviews with clear state definitions, table fill orders, and a worked LCS example.
3 min read
Binary Tree Traversals for Interviews
Master binary tree traversals for coding interviews. Learn when to use inorder, preorder, postorder, and level order with concrete examples and a quick.
5 min read
Recursion vs Iteration in DSA: Which to Write in an Interview
Master recursion and iteration for coding interviews. Learn call stack limits, DFS, tree traversals, and dynamic programming trade-offs.
3 min read
Linked List Interview Questions: Fast and Slow Pointers Explained
Master Floyd's cycle detection and fast-slow pointers for linked lists. Learn the math behind finding cycles, middles, and palindromes with clear examples.
5 min read
Swift, UIKit and Algorithms: What iOS Hiring Loops Test
Understand what iOS interview loops test across data structures, Swift memory management, and UIKit so you can allocate your prep time effectively.
4 min read
LeetCode vs GeeksforGeeks vs Codeforces
LeetCode is the primary tool for Indian campus placements. Use GeeksforGeeks for theory and Codeforces only if you have spare time.
5 min read
Mastering Monotonic Stacks for Linear Time Array Problems
Master the monotonic stack pattern to solve Next Greater Element, Daily Temperatures, and Histogram problems in linear time instead of quadratic.
3 min read
Binary Search Beyond Sorted Arrays: Searching on the Answer
Learn how to apply binary search to answer spaces, set correct bounds, avoid off‑by‑one traps, and see a step‑by‑step example for the ship‑packages problem.
3 min read
How to Improve Coding Interview Performance Beyond Problem Counts
Discover why solving hundreds of coding problems does not guarantee interview success and learn practical strategies to fix it.
3 min read
Dynamic Programming: Where to Start If It Feels Impossible
Master dynamic programming from scratch with plain recursion, memoization, and tables using Fibonacci, stairs, and house robber examples.
3 min read
Learning DSA With ChatGPT Without Fooling Yourself
How to use ChatGPT and other AI tools for DSA practice so your own problem solving improves: hint-only prompts, checked code reviews and mock interviews.
3 min read
A Guide to Using Hints and Solutions for DSA Practice
A time-box and hint rule for DSA practice: how long to try, which kind of stuck needs help, and how to learn from a solution after you read it.
4 min read
DSA plan for non-CS students aiming for software roles
A from-zero DSA plan for ECE, EEE, Mechanical and Civil students aiming at software roles: eligibility, one language, topic order and a weekly rhythm.
5 min read
BFS or DFS: How to Pick the Right Traversal in an Interview
Learn when to use BFS vs DFS in coding interviews, with clear criteria, memory trade‑offs, recursion limits, and concrete grid examples for interview scenarios.
2 min read
How to Revise DSA Problems You Have Already Solved
Learn a practical, research-backed routine to revise solved DSA problems so the core approach sticks for coding interviews.
3 min read
How to Prepare for the Amazon SDE II Online Assessment
Amazon SDE II online assessments feature two coding questions in 90 minutes.
4 min read
Which Sorting Algorithms to Learn for Interviews
Bubble sort is rarely the answer in a coding interview. See which sorting algorithms to learn, their time complexity, and the problems where each one shows up.
3 min read
How to Use an Online DSA Compiler for Python and JavaScript
Practise DSA in an online compiler that runs Python and JavaScript in your browser, takes custom input and steps through your code line by line. Free, no login.
3 min read
Striver A2Z vs Love Babbar 450 vs Apna College
Striver A2Z, Love Babbar 450 and Apna College sheets overlap more than they differ. Here is how they compare and which one fits your time and level.
3 min read
How Many DSA Problems Should You Solve Per Day?
One to two new problems a day beats a heroic five if you review what you solve. Here is the arithmetic behind that, and how to set your own daily number.
3 min read
Two Pointers vs Sliding Window: How to Tell Which One to Use
Two pointers and sliding window look alike but solve different problems. Here is a two-question test that picks the right one before you write any code.
3 min read
5 DSA Preparation Mistakes That Waste Months
Five specific DSA preparation errors cause months of wasted effort. Learn how to fix your study strategy, track weak topics, and align practice.
4 min read
Is DSA Required for a Data Engineer Interview?
Data engineer interviews focus on SQL and system design, not heavy DSA. Learn which coding topics matter and how to allocate your prep time effectively.
4 min read
You Solved the Consensus 75. What Next?
A practical guide for post-75 problem solvers: how to select the next 100 problems, when to start timed mocks, and why spaced repetition beats new questions.
4 min read
DSA Topics That Matter Most After 2 Years of Experience
Prioritize trees, graphs, and dynamic programming over easy arrays. A practical guide to shifting DSA prep strategy for engineers with 1-3 years of experience.
4 min read
Is DSA Required for a Security Engineer Interview?
Security engineer interviews require DSA, but the focus shifts to bit manipulation and hashing.
3 min read
Is DSA Required for a Machine Learning Engineer Interview?
Yes, ML Engineer interviews require DSA. Learn which topics matter for coding rounds and how to prioritize your prep.
4 min read
Is DSA Required for an SDET / QA Automation Engineer?
SDET interviews focus on testing concepts and frameworks, not heavy DSA. Learn which basic topics matter and how to prioritize your prep for automation roles.
4 min read
Is DSA Required for a DevOps Engineer Interview?
DSA is required for DevOps interviews in India, but the focus is on arrays, hashing, and basic graphs. Heavy DP is rarely asked. Focus on systems logic.
3 min read
The 27 DSA patterns coding interviews actually test
Interviews reuse about thirty problem shapes. Here are the 27 patterns, each with a runnable template and six LeetCode problems that teach it.
3 min read
JavaScript Coding Interview Questions
The data-structures and algorithms questions asked in JavaScript interviews, in the order to practise them, with the Map, Set, sort.
4 min read
Coding Interview Questions by Topic
Coding interview questions organised by the 22 DSA topics interviews are built from, with the problem count for each topic, the first problem to solve.
3 min read
How to merge Striver, Babbar, and Apna College DSA sheets
One DSA sheet built from Striver A2Z, Love Babbar 450 and Apna College: 370 problems, 22 topics, duplicates removed, and the order changed for the job you are.
3 min read
DSA for Machine Learning Engineer Interviews
ML engineer interviews do include a coding round, but it is weighted differently: arrays, hashing, strings and a little DP.
4 min read
Binary Search Beyond Sorted Arrays: The Search-on-Answer Pattern
Half the binary search questions in interviews have no sorted array. They binary search the answer itself.
4 min read
Graph Algorithms for Coding Interviews
Graphs are the largest topic in most DSA sheets and the most skipped. Four algorithms cover nearly every interview graph question.
5 min read
DSA for SDET and QA Automation Interviews
SDET interviews test DSA, but not the same DSA as an SDE round. Strings, arrays, hashing and simple recursion dominate; graphs and hard DP rarely appear.
4 min read
How to Use Spaced Repetition to Remember Solved DSA Problems
Solving a problem once does not make it stay. A spaced revision schedule (1, 3, 7, 14, 30 days) built on a confidence rating keeps 300 solved problems.
4 min read
Dynamic Programming for Interviews
DP is not 51 separate tricks. Almost every interview DP problem is one of six patterns.
5 min read
Sliding Window Pattern Explained
The sliding window pattern turns O(n^2) substring and subarray questions into O(n).
5 min read
Company-Wise DSA Sheets, Built From Verified Tags, Not Guesses
DSA Tracker now has company-wise sheets (Microsoft, Amazon, Flipkart, Google and more), a sheets hub, revision confidence tracking.
3 min read
DSA for Data Analyst & Data Science Roles, How Much Do You Need?
Is DSA needed for data analyst and data science roles? It depends which role.
3 min read
DSA for Frontend Developer Interviews, What to Actually Study
Do frontend developers need DSA? Yes, but a narrower slice. The high-frequency patterns for frontend coding rounds, what you can safely skip.
3 min read
Time Complexity & Big-O for Interviews, Explained
Big-O without the math jargon: the complexities that actually come up in interviews, how to analyse your code on the spot, and what interviewers really want to.
3 min read
DSA for Backend Developer Interviews, What Matters
Backend interviews test more than DSA, hash maps, trees, graphs, plus system design, databases, and concurrency.
2 min read
DSA for TCS, Infosys & Wipro, What Mass Recruiters Test
TCS NQT, Infosys, and Wipro don't test LeetCode-hard DSA. They test fundamentals, aptitude, and basic coding.
2 min read
DSA for Off-Campus Placements 2026, A Realistic Plan
Off-campus is a different game from on-campus: no college filter, far more competition per seat, and your resume has to survive an ATS before anyone sees your DSA. Here's a plan that accounts for all of it.
3 min read
Google DSA Interview: Patterns, Communication, and Googleyness
DSA for the Google interview, decoded: intervals, greedy, binary-search-on-answer, communication scored as much as correctness, Googleyness.
8 min read
Company-Specific DSA Without LeetCode Premium (Free Alternatives)
LeetCode Premium gates company tags behind $35/mo. Here's how to get most of that value for free, public company-frequency lists, trusted sheets.
7 min read
DSA for the Amazon SDE Interview, A Deep, Specific Guide
Amazon's SDE-1 loop is the most pattern-predictable of the big tech interviews, grids, graphs, trees, an OA debug section, and Leadership Principles that count.
8 min read
The 21 DSA Topics That Cover 90% of Coding Interviews
The DSA topics that actually show up in interviews, ranked by how often they appear, so you know exactly what to master first and what to leave for last.
3 min read
How to Crack DSA for Placements in 90 Days
A realistic 90-day DSA plan for placements, week-by-week milestones, daily problem targets, revision cadence, and how to avoid the burnout that kills most prep.
3 min read
Striver A2Z vs Love Babbar 450 vs Apna College
An honest comparison of the three most popular DSA sheets, Striver A2Z, Love Babbar 450, and Apna College, by size, structure, difficulty curve.
3 min read
DSA topics to prioritize for frontend, backend, and data roles
A role-by-role DSA roadmap. What frontend, backend, data, and generalist SDE interviews really test, and the topics you can safely de-prioritise for each.
3 min read
The 15 DSA Patterns That Cover 90% of Coding Interviews
A pattern cheat sheet for coding interviews: recognition triggers for sliding window, two pointers, DP and 12 more, plus a practical study loop.
4 min read
9 DSA Interview Mistakes That Get Freshers Rejected
Nine coding interview mistakes that fail freshers even with a working solution, coding before clarifying, silent solving, skipped complexity.
5 min read
How Many LeetCode Problems Are Enough to Crack Placements?
You don't need 1000 LeetCode problems for placements. Here's why ~100-150 well-chosen, pattern-covering problems beat 500 random ones, and how to pick them.
4 min read
How to Revise DSA in the Final Week Before an Interview
You can't re-solve 370 problems in seven days, and you shouldn't try. Here's a spaced-repetition revision system that targets only your weak patterns, fast.
4 min read
Service vs Product Company DSA Prep: TCS to FAANG
How DSA prep for TCS, Infosys, and Wipro differs from product-based and FAANG interviews, a two-tier map plus a switch roadmap for service-company engineers.
4 min read
C++ vs Java vs Python for DSA Interviews: Which to Pick
C++ is fast, Java is explicit, Python is short. But interviewers grade your problem-solving, not your syntax. Here is how to pick the one language you'll actually stick with.
4 min read
Blind 75 vs NeetCode 150 vs Striver SDE Sheet
Three of the most-recommended DSA lists on the internet, side by side. Which to grind depends on your timeline and whether you want a curriculum or a minimal hit-list. Here's the honest call.
3 min read
Google, Amazon & Microsoft DSA Questions for Freshers
Amazon, Google, and Microsoft don't test the same DSA. What each weights for freshers, and how to filter your prep to one company's high-frequency patterns.
3 min read