Course 06 · Orientation
Design Method
Requirements, numbers, interfaces
The loop used in design reviews and interviews: agree on the job, estimate the few numbers that change the shape, then write the API and the data before drawing boxes.
The course journey
Build one family of skills at a time
Each technique is three short lessons, and each one builds on the lesson before it. A lesson walks through one problem step by step, then hands it to you along with a few more to solve on your own.
- 01Start here
Requirements
Functional verbs, qualities with numbers, and an explicit out-of-scope list.
- Stage 1Functional & Non-Functional RequirementsTurn user verbs and measurable qualities into a list the design must satisfy1 Lesson · 1 Drill
- Stage 2Clarifying Questions That Change the DesignAsk first the questions whose answers add or remove a component1 Lesson · 1 Drill
- Stage 3Scoping with Explicit Non-GoalsName what the first version will not build, with a reason for each1 Lesson · 1 Drill
- 02Pro
Estimation
The few numbers that decide cache, shard, or queue.
Stage 1
Back-of-the-Envelope Rates & Storage
Stage 2
Peak & Outlier Estimation
Stage 3
Bandwidth-Driven Estimation
- 03Pro
Interfaces
The API and the rows, before the network diagram.
Stage 1
API Contracts & Data Models
Stage 2
Internal Interfaces & Shared State
Stage 3
Read/Write Path Split & Cursor Pagination