Core Computer Science for Interviews
After DSA, core computer science is what fresher interviews spend the most time on — and it is where memorised definitions fall apart fastest. This track covers the two areas that come up in nearly every round, and does it by explaining mechanisms rather than listing terms, because that is what survives a follow-up question.
▶ Start with The four pillarsPhase 1 · Design fundamentals
01OOPs ConceptsThe four pillars, what they buy you, and when to prefer compositionThe four pillars · Inheritance vs composition · Polymorphism in practice3 lessons
Phase 2 · Data
01DBMS & SQLNormalisation, indexes and what makes a query slowNormalisation · Indexes & query cost2 lessons
How to use this track
1. Follow the order. Each lesson assumes the one before it. Every page has previous and next buttons, so you can read the whole track without going back to a menu.
2. Do the practice. Lessons end with problems tagged by pattern, so you can tell whether you learned the idea or just the example.
3. Test recall, not recognition. A topic quiz at the end of each chapter is a far better check than re-reading the page.
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