Campus placement runs on a clock you do not control. Here is what each round actually tests, in the order you will face it, with practice for every one.
Campus placement is a sequence, not a single interview, and the order matters more than most students are told. An aptitude or online assessment round filters the majority of applicants before a human reads anything. Whatever comes after it - technical interviews, HR - only happens for people who clear a test that has almost nothing to do with engineering ability. Preparing in the order the rounds arrive is the single highest-leverage decision in the whole process.
The technical rounds then reward depth over coverage. A student who has solved 150 problems across every pattern and can explain their reasoning out loud performs better than one who has attempted 600 and pattern-matched from memory, because the interviewer asks follow-ups. This is also where on-campus and off-campus diverge: campus drives lean heavily on DSA and fundamentals, while off-campus applications to product companies add low-level design and, at Indian product companies, a machine coding round.
The part almost nobody rehearses is speaking. Interviewers are grading how you narrate a decision, handle a hint, and recover when you get stuck - and those are separate skills from solving the problem on paper. Reading solutions builds none of them. That gap is what mock rounds exist to close, and it is why the last few weeks before a drive are better spent talking through problems than reading more of them.
60-90 min
Quants, logical reasoning and verbal. The round that eliminates the most candidates, and the one most students underprepare.
90-120 min
Timed DSA problems on HackerRank, HackerEarth or a similar platform. Usually 2-3 questions with hidden test cases.
45-60 min
Arrays, strings, trees and hashing, plus questions on your own projects and CS fundamentals.
45-60 min
Harder problem solving, OOP and basic design. Product companies add LLD here.
20-30 min
Why this company, relocation, bond terms and your projects. Rarely the reason for rejection, occasionally the reason for a lower band.
Pre-final year
DSA patterns from scratch, one language properly, CS fundamentals alongside coursework. Add aptitude late.
Final year, pre-drive
Pattern-wise DSA at volume, aptitude twice a week, OOP and DBMS revision, two projects you can defend in depth.
Drive announced
Mock rounds out loud, timed assessments, revision of what you already know. Starting new topics here costs more than it returns.
Six to nine months before your drive is comfortable for DSA, which is the slowest skill to build. Aptitude needs weeks rather than months, so it can come later. If you have less time than that, the answer is not to compress everything - it is to drop breadth and drill the rounds you will actually face first.
Around 150 to 200, chosen to cover every major pattern, beats a much larger number attempted without structure. The bar is whether you can explain an approach and its complexity out loud and handle a follow-up, not how many you have seen. Most students who struggle in interviews have solved plenty and rehearsed none.
It is the round that rejects the most people, because it is applied first and applied mechanically. Clearing it is a prerequisite for every technical round being relevant at all, and unlike DSA it is largely a speed and familiarity problem, so a few weeks of timed practice moves the needle a long way.
Off-campus applications to product companies add low-level design and, at most Indian product companies, a machine coding round where you build working, extensible code in 60 to 90 minutes. Campus drives usually skip both and weight DSA and fundamentals more heavily. If you are targeting both, prepare the campus shape first - it is the shared base.
Stop starting new topics and start speaking. Timed assessments, mock rounds out loud, and revision of what you already know. New material learned in the final weeks is the least likely to survive interview pressure, and the speaking practice is the part nothing else in your preparation covers.
Aptitude filters hardest and prepares fastest. Then move to DSA, and rehearse out loud before the drive.