Which shortcuts are safe to take in an MVP

Debt is a decision, not an accident

Shipping fast means leaving things unfinished on purpose. The skill is knowing which unfinished things stay cheap and which compound.

Usually safe

• No caching layer. Add it when a real query is slow.
• Manual back-office steps. A human running a script is fine at low volume.
• One large module instead of clean boundaries. Splitting later is mechanical work.
• Minimal admin tooling. Database access plus care covers the early period.

These share a trait: fixing them later costs roughly what it would cost now.

Rarely safe

• Anything touching authentication or authorisation. Retrofitting access control across a codebase that assumed everyone could see everything is close to a rewrite.
• Data you cannot migrate. A schema with no clear identity for each record becomes very expensive once real records exist.
• Money handling without an audit trail. Reconstructing what was charged, when, and why is not something you can add afterwards.
• No backups. This is not debt. It is an unfunded liability.

The discipline that keeps this honest

Write the shortcut down when you take it, with the condition that triggers repayment: at a thousand users, before the first enterprise customer, when this query passes a threshold. Undocumented debt is indistinguishable from an oversight six months later, and gets defended as a design decision by people who were not there.