Ninety days is enough time to go from "I know loops" to "interview-ready" — but only if you spend it well. Most students fail not from lack of effort but from bad allocation: six weeks perfecting arrays, then panicking through graphs and DP in the final fortnight. This plan front-loads the hard topics while you still have runway.
Arrays, strings, hashing, two pointers, sliding window, basic recursion. These are the alphabet of every harder topic. Aim to recognise the pattern, not memorise solutions.
Milestone: ~70 problems, and you can spot a sliding-window problem on sight.
Linked lists, stacks & queues, trees (traversals, BST), heaps. This is where most people slow down — budget for it. Do trees thoroughly; they're the gateway to graphs.
Milestone: ~90 problems cumulative; comfortable with recursion on trees.
Graphs (BFS/DFS, topological sort, shortest paths) and dynamic programming. This is where interviews are won and lost. If you've front-loaded correctly, you have three full weeks of fresh energy for the material everyone else rushes.
Milestone: You can model a problem as a graph and choose the right traversal; you recognise the 6–7 canonical DP patterns.
No new topics. Re-solve everything you flagged, do timed mocks, and practise talking through your approach out loud. The goal of the last two weeks is speed and composure, not coverage.
Milestone: Two clean mock interviews where you narrate your reasoning end-to-end.
This timeline assumes a generalist SDE target. If you're aiming at a specific role, the weights shift — a frontend or data role lets you compress Phase 3. That's the advantage of letting your role set the order instead of marching through a sheet top to bottom. Set your role, let the plan reshape, and track it without the spreadsheet.
Amazon is the most predictable big-tech loop a fresher can prepare for — but only if you know its actual lean: grids and graphs over exotic DP, a debugging section in the OA, and Leadership Principles that quietly decide SDE-1 offers. Here's the deep, Amazon-only plan.
LeetCode Premium's company tags cost roughly $35/month — and the moment you have an interview date, that paywall feels mandatory. It isn't. Here's how to reconstruct most of that signal for free, and the one thing Premium genuinely does better.