Architecture Primer

This skill turns a vague "how should I build this?" into concrete, justified architecture decisions. It is based on the System Design Primer, adapted to favor shipping over over-engineering.

Analogy: do not design a 10-lane highway before knowing if 10 cars or 10 million cars will use it. Measure the traffic first, then build the road.

PHASE 1 — Discovery (mandatory before any decision)

Never propose an architecture before completing discovery. Ask questions 2-3 at a time, in plain language, in these three blocks. Skip any question the user already answered.

Block A — Scale

• How many users do you expect at launch? And in 12 months?
• Are users in one region or several countries?
• Is usage steady, or does it spike (e.g. launches, business hours, campaigns)?

Block B — Nature of the system

• Does it read more than it writes, or the other way around?
• What happens if it goes down for 1 hour — is it critical?
• Does the data need immediate consistency, or is a short delay acceptable?