DSA by domain
Web & Backend
Product engineering: the everyday interview core of arrays, strings, two pointers and sliding window.
What the roles here have in common
2 topics are core for every one of the 4 roles in Web & Backend. Whatever job you end up interviewing for inside this domain, this is the part that was never optional:
- Arrays
- Strings
12 more topics are core for some of these roles but not all of them. Which ones apply is exactly what changes when you pick your role below:
- BST
- Binary Search
- Binary Trees
- Dynamic Programming
- Graph
- Linked List
- Queue
- Recursion
- Sliding Window
- Sorting
- Stack
- Two Pointers
Roles in this domain
Same 370 problems, re-sequenced per role. Pick the exact one you are interviewing for — the roles with a full guide are linked; the rest work inside the app today.
- backend / SDEThis is the widest DSA bar of any role here: 10 core topics, 260 of our 370 problems. Trees, graphs and dynamic programming carry the loop, and there is no shortcut around them — a generalist SDE interview can pull from almost anywhere. Budget the most time of any track on this list.
- frontendFrontend loops lean on arrays, strings and two-pointer work: 6 core topics, 84 of our 370 problems. Hard dynamic programming is rare. That is a materially smaller surface than a backend loop — grinding a generalist sheet top-to-bottom means spending weeks on segment trees your interview will never mention.
- full-stackFull-stack loops blend frontend array/string work with backend structure questions: 7 core topics, 97 problems, and an unusually large second tier (103 problems). Per-topic depth is shallower than a pure backend loop, but the spread is wider — you get asked a little of everything.
- SDET / QASDET loops are not the light coding round people expect. Candidate reports from 2024-2025 describe Amazon running 5 DSA questions in 90 minutes and Zomato opening with 3. Arrays and strings dominate: 7 core topics covering 96 of our 370 problems, with 56 of those 96 at medium difficulty. Budget real algorithm time, not a token pass.