|
CURATED QUESTIONS 155+ Interview Problems |
CORE DISCIPLINES 4 + 1 OS • DBMS • CN • OOP |
PEDAGOGICAL MODEL 3-Layer Intuitive → Deep → Summary |
ACCESS 100% Free Open Source Resource |
Most interview preparation materials either jump straight into low-level code without context or recite rote textbook definitions. TopDown CS structures every question around three layers designed for deep technical comprehension and rapid recall:
|
Real-world engineering analogies and physical intuitions that deconstruct abstract low-level mechanisms before touching syntax or theory. |
Architectural diagrams, OS kernel internals, memory layouts, bytecode inspections, concurrency execution traces, and failure modes. |
Crisp, high-signal verbal takeaways calibrated specifically for what engineering hiring managers and bar-raisers actively listen for. |
Tip
Recommended Study Flow: Start with Essentials in each track to build your core architectural foundation, advance to Additional for deep-dive system nuances, and tackle Problems to master numerical calculations and formal proofs.
The repository contains 155+ curated questions organized by subject and module tier:
43 Curated Questions • 3 Modules
| Module | Questions | Difficulty | Core Topics Covered | Explore |
|---|---|---|---|---|
| OS Essentials | 20 | 🟢 9 Easy • 🟡 11 Med | Processes, threads, CPU scheduling, virtual memory, paging, deadlocks, IPC | Explore → |
| OS Additional | 15 | 🟡 8 Med • 🔴 7 Hard | Priority inversion, spinlocks, TLB flushing, kernel threads, POSIX signals | Explore → |
| OS Problems | 8 | 🟡 7 Med • 🔴 1 Hard | Scheduling Gantt charts, Banker's algorithm, Bélády's anomaly proofs | Explore → |
33 Curated Questions • 2 Modules
| Module | Questions | Difficulty | Core Topics Covered | Explore |
|---|---|---|---|---|
| DBMS Essentials | 15 | 🟢 7 Easy • 🟡 8 Med | ACID guarantees, WAL protocols, B+ Trees, transaction states, SQL order, indexing | Explore → |
| DBMS Additional | 18 | 🟢 1 Easy • 🟡 14 Med • 🔴 3 Hard | BCNF vs. 3NF normalization, OLTP vs. OLAP, ER schema translation, query planning | Explore → |
26 Curated Questions • 3 Modules
| Module | Questions | Difficulty | Core Topics Covered | Explore |
|---|---|---|---|---|
| CN Essentials | 10 | 🟢 5 Easy • 🟡 4 Med • 🔴 1 Hard | OSI vs. TCP/IP, TCP 3-way handshake & teardown, flow control, DNS, HTTP/2/3 | Explore → |
| CN Additional | 6 | 🟢 1 Easy • 🟡 4 Med • 🔴 1 Hard | Cookie sessions vs. JWTs, WebSockets scaling, CORS preflight, TLS 1.3 handshake | Explore → |
| CN Problems | 10 | 🟢 1 Easy • 🟡 6 Med • 🔴 3 Hard | Subnetting, VLSM design, CRC-32 division, Hamming codes, framing efficiency | Explore → |
53 Curated Questions • 4 Modules
| Module | Questions | Difficulty | Core Topics Covered | Explore |
|---|---|---|---|---|
| OOP Essentials | 22 | 🟢 7 Easy • 🟡 11 Med • 🔴 4 Hard | Core pillars, SOLID principles, HashMap internals, memory models, immutability | Explore → |
| OOP Additional | 17 | 🟢 3 Easy • 🟡 11 Med • 🔴 3 Hard | Static vs. dynamic binding, method hiding, covariant returns, generics, reflection | Explore → |
| Code Tracing | 8 | 🟡 4 Med • 🔴 4 Hard | Step-by-step traces: class initialization, MRO linearization, variable shadowing | Explore → |
| Design Patterns | 6 | 🟡 5 Med • 🔴 1 Hard | Idiomatic implementations: Singleton, Factory, Strategy, Builder, Decorator, Observer | Explore → |
8 High-Scale Schema Designs
| Module | Questions | Difficulty | Core Topics Covered | Explore |
|---|---|---|---|---|
| Database Design | 8 | 🟡 8 Med | High-scale schemas: Wallets, Splitwise, Swiggy/Zomato, Uber/Ola, Zerodha, Amazon | Explore → |
TopDown CS is built with Docusaurus 3, React, and KaTeX. You can run the entire site locally:
# 1. Clone the repository
git clone https://github.com/jaicharan-dev/topdown-cs.git
cd topdown-cs/site
# 2. Install dependencies
npm install
# 3. Start local development server
npm startThe documentation server will launch at http://localhost:3000.
To test the production build locally:
npm run build
npm run serveContributions, errata corrections, and question suggestions are welcome!
- 🐛 Report Errata: Found a typo or inaccurate technical detail? Please open an issue.
- 💡 Suggest Questions: Have a question that frequently appears in technical rounds? Open an issue with the proposed topic.
- 🚀 Submit Improvements: Fork the repo, create a branch (
git checkout -b feature/topic-improvement), and submit a Pull Request following our 3-step question structure.
⭐ If you find TopDown CS helpful for your interview preparation, consider starring the repo!