[06] How I Think

Backend First

A pretty UI cannot save a broken system. I prioritize data integrity, race-condition handling, and API contract stability over frontend polish.

Debugging Mindset

"It works on my machine" is not an answer. I assume the network is unreliable, the database will time out, and users will send malformed JSON.

> logging.error("Transaction failed: " + e.message)
> metrics.increment("payment_failure")
> alert_admin() // if failure_rate > 5%

What I'd Redesign

Looking back at Skill-Swap: I used MongoDB for everything. Today, I would use PostgreSQL for the user accounts to enforce stricter schema constraints, and keep MongoDB only for the unstructured chat logs.