Most candidates prep in the wrong order — grinding LeetCode hard problems before they can clear the aptitude round. Here's the sequence that actually maps to how hiring loops work.
1. Aptitude & reasoning first
Many hiring processes start with a timed aptitude or online assessment. It's the cheapest round to clear with practice — quant shortcuts, logical reasoning, and a bit of verbal. Two weeks of daily timed mocks is usually enough.
2. CS core subjects
Service companies (TCS, Infosys, Wipro) lean heavily on OS, DBMS, CN and OOPs in both MCQs and the interview. Crisp revision notes beat re-reading textbooks.
3. DSA — patterns, not problems
Don't memorise 500 problems. Learn ~15 patterns (two pointers, sliding window, BFS/DFS, DP) and the rest transfer. Start with Blind 75, then itjobprep 100 for the most-asked set.
4. Build one real project
A single polished full-stack project that you can explain end-to-end beats five half-finished tutorials. It's what turns a screening into a conversation.
5–8. Behavioral, company prep, mocks, apply
Prepare STAR answers for the common HR questions, study your target company's specific question bank, do full timed mock loops, and track every application so nothing slips.