The Completion Checklist — You're 'Done' When…
In one line
The syllabus's graduation test: the things you must be able to do with the tutorial closed. This is the actual objective of the whole course.
Key ideas
- 01
LLD: take an unfamiliar problem and identify requirements and entities without prompting.
- 02
LLD: assign responsibilities and choose abstractions cleanly (who should own this behavior?).
- 03
LLD: use SOLID where it improves changeability, not as forced decoration.
- 04
LLD: select design patterns because a concrete design problem demands them.
- 05
LLD: handle concurrency where shared state requires it — and name the mechanism.
- 06
LLD: write production-quality Java with meaningful tests.
- 07
LLD: explain how the design changes when a new business rule arrives.
- 08
HLD: clarify functional and non-functional requirements out loud.
- 09
HLD: estimate QPS/RPS, storage, bandwidth, memory.
- 10
HLD: design APIs and data models with reasoning.
- 11
HLD: choose DBs, caches, queues and communication styles with reasons (not vibes).
- 12
HLD: explain bottlenecks and scaling paths with numbers.
- 13
HLD: discuss consistency, reliability, retries, idempotency and failure handling.
- 14
HLD: discuss security, observability, disaster recovery and cost.
- 15
HLD: explain trade-offs and alternatives — never a single memorized architecture.
- 16
Final goal: given ANY new system — Uber, Instagram, payments, a notification platform, a test-execution platform, a CI/CD platform, a multi-tenant SaaS — run the same reasoning framework and adapt.
Explain without notes
Pick a system the syllabus never covered (e.g. a fitness app) and pass every bullet in this checklist.
Practice
Self-grade weekly against this list; any 'no' is next week's topic.
Trade-offs
- ↔
Memorizing a good answer for Twitter is the false finish; this checklist is the real one.
Completion checklist
Every bullet above is a 'yes' with the tutorial closed.