Week one · two topics a day

The first 10 study sessions

Do not tour the roadmap — run it. These ten sessions build the exact foundation the rest of the course assumes: fundamentals, OOP relationships, SOLID, responsibilities, then the patterns, then two full LLD problems. Every session uses the learning loop from the syllabus: learn → close the tutorial → explain without notes → implement → break it → fix it → explain trade-offs.

System Design Fundamentals

Phase 0 — the 8 questions, LLD vs HLD, NFRs, trade-offs.

≈45 min

OOP relationships

Encapsulation, composition, aggregation, association; composition over inheritance.

≈45 min

SOLID

Each letter tied to the production problem it prevents.

≈45 min

UML + object responsibilities

Class relationships + who owns which behavior.

≈45 min

Factory + Builder

Creational patterns with runnable Java.

≈45 min

Strategy + Observer

The two behavioral patterns that appear in every LLD.

≈45 min

Adapter + Decorator

Structural patterns for integration and stacking.

≈45 min

State + Command

Vending machines and undo-aware systems.

≈45 min

LLD: Parking Lot

Your first full problem with complete Java + concurrency.

≈45 min

LLD: Vending Machine

State pattern applied end to end.

≈45 min

From day 11 onward, continue sequentially: every phase in order, each topic through the same loop. Pacing beats intensity — two topics deep beats ten shallow.

Start at the roadmap Then the two templates

Command Palette

The first 10 study sessions