Topics Knowledge Base

Learning Workspace & System Knowledge Base

A curated collection of interactive lessons, reference guides, and interview prep notes covering C++ Fundamentals, Database Internals, Distributed Systems, Object-Oriented Software Design, and Aptitude.

1. C++ Fundamentals & Internals

19 Lessons — A Tour of C++, Stroustrup: types, classes, RAII, templates, ranges, concurrency.

View the C++ course dashboard →

  1. Lesson 1: The Basics
  2. Lesson 2: User-Defined Types
  3. Lesson 3: Separate Compilation
  4. Lesson 4: Error Handling
  5. Lesson 5: Classes
  6. Lesson 6: Essential Operations
  7. Lesson 7: Templates
  8. Lesson 8: Concepts and Generic Programming
  9. Lesson 9: Library Overview
  10. Lesson 10: Strings and Regular Expressions
  11. Lesson 11: Input and Output
  12. Lesson 12: Containers
  13. Lesson 13: Algorithms
  14. Lesson 14: Ranges
  15. Lesson 15: Pointers and Containers
  16. Lesson 16: Utilities
  17. Lesson 17: Numerics
  18. Lesson 18: Concurrency
  19. Lesson 19: History and Compatibility

2. Object-Oriented Programming (OOP)

21 Lessons across Java, C++, and Python — SOLID, polymorphism, inheritance, memory management.

View the OOP course dashboard →

  1. Lesson 0001: Java Basics & Primitive Types
  2. Lesson 0002: OOP Fundamentals & 4 Pillars
  3. Lesson 0003: Classes and Objects
  4. Lesson 0004: Attributes and Methods
  5. Lesson 0005: Constructors & Destructors
  6. Lesson 0006: Encapsulation & Data Hiding
  7. Lesson 0007: Access Modifiers & Qualifiers
  8. Lesson 0008: Inheritance
  9. Lesson 0009: Polymorphism
  10. Lesson 0010: Abstraction
  11. Lesson 0011: Interfaces
  12. Lesson 0012: The static Keyword
  13. Lesson 0013: Inner & Nested Classes
  14. Lesson 0014: Relationships Between Classes
  15. Lesson 0015: Object Cloning
  16. Lesson 0016: Exception Handling
  17. Lesson 0017: Generics & Templates
  18. Lesson 0018: File Handling
  19. Lesson 0019: SOLID Principles
  20. Lesson 0020: Object Lifecycle & Memory
  21. Lesson 0021: Advanced Keywords & Qualifiers

3. Designing Data-Intensive Applications (DDIA)

12 Chapters by Martin Kleppmann — storage engines (B-trees, LSM), replication, transactions, consensus (Raft, Paxos).

View the DDIA course dashboard →

  1. Chapter 1: Reliable, Scalable, and Maintainable
  2. Chapter 2: Data Models and Query Languages
  3. Chapter 3: Storage and Retrieval
  4. Chapter 4: Encoding and Evolution
  5. Chapter 5: Replication
  6. Chapter 6: Partitioning (Sharding)
  7. Chapter 7: Transactions
  8. Chapter 8: Trouble with Distributed Systems
  9. Chapter 9: Consistency and Consensus
  10. Chapter 10: Batch Processing
  11. Chapter 11: Stream Processing
  12. Chapter 12: The Future of Data Systems

4. Database System Concepts

5 Lessons — Silberschatz, Korth & Sudarshan DBMS Architecture & SQL.

View the Database System Concepts dashboard →

  1. Lesson 1: Introduction to DBMS
  2. Lesson 2: Relational Model
  3. Lesson 3: Introduction to SQL
  4. Lesson 4: Intermediate SQL
  5. Lesson 5: Advanced SQL

5. High-Level Design

0 Lessons — architecture, scalability, and system design tradeoffs.

View the High-Level Design dashboard →

6. Quantitative Aptitude

25 Lessons — placement math: percentages, time & work, speed-distance, profit & loss, P&C.

View the Quantitative Aptitude dashboard →

  1. Lesson 0001: Numbers
  2. Lesson 0002: LCM and HCF
  3. Lesson 0003: Work and Wages
  4. Lesson 0004: Pipes and Cisterns
  5. Lesson 0005: Time, Speed, and Distance
  6. Lesson 0006: Trains, Boats, and Streams
  7. Lesson 0007: Percentage
  8. Lesson 0008: Ratio and Proportion
  9. Lesson 0009: Partnership
  10. Lesson 0010: Mixtures and Alligation
  11. Lesson 0011: Algebra
  12. Lesson 0012: Average
  13. Lesson 0013: Age
  14. Lesson 0014: Profit and Loss
  15. Lesson 0015: Simple Interest
  16. Lesson 0016: Compound Interest
  17. Lesson 0017: Mensuration 2D
  18. Lesson 0018: Trigonometry & Height and Distances
  19. Lesson 0019: Progressions
  20. Lesson 0020: Logarithms
  21. Lesson 0021: Permutation and Combination
  22. Lesson 0022: Probability
  23. Lesson 0023: Geometry
  24. Lesson 0024: Race
  25. Lesson 0025: Simplification & Approximation

7. Logical Reasoning

12 Lessons — puzzles, deduction & critical reasoning.

View the Logical Reasoning dashboard →

  1. Lesson 0001: Series — Missing Numbers & Odd One Out
  2. Lesson 0002: Data Sufficiency
  3. Lesson 0003: Assumptions, Conclusions & Courses of Action
  4. Lesson 0004: Puzzles
  5. Lesson 0006: Cubes
  6. Lesson 0007: Alphanumeric Series
  7. Lesson 0008: Reasoning Analogy
  8. Lesson 0009: Blood Relations
  9. Lesson 0010: Calendar
  10. Lesson 0011: Coding and Decoding
  11. Lesson 0012: Dices
  12. Lesson 0013: Clocks

8. SQL — Structured Query Language

11 Lessons — Why SQL exists, DB/table basics & ALTER, query fundamentals, filtering essentials, aggregation & COUNT, single-row functions, CASE, string functions, editing data & tables, merging results, joins deep dive.

View the SQL course dashboard →

  1. Lesson 0001: Why SQL Is So Often Learned the Wrong Way
  2. Lesson 0002: Database & Table Basics
  3. Lesson 0003: Query Fundamentals
  4. Lesson 0004: Filtering Essentials
  5. Lesson 0005: Aggregation — GROUP BY, HAVING & COUNT
  6. Lesson 0006: Single-Row Functions — ROUND, ABS, GREATEST/LEAST, IFNULL & COALESCE
  7. Lesson 0007: CASE Expressions — Conditional Logic
  8. Lesson 0008: String Functions — Cleaning & Matching Text
  9. Lesson 0009: Editing Data and Tables — INSERT, UPDATE, DELETE & ALTER
  10. Lesson 0010: Merging Query Results — UNION, UNION ALL & Intersection
  11. Lesson 0011: Joins Deep Dive — LEFT, RIGHT, INNER, FULL, CROSS & SELF