Mercado Livre

Context

Large-scale operation with complex business rules.

Problem

Slow responses and risk when changing rules.

What I did

Improved performance and created shared toolkits for complex rules.

• Built shared rule toolkits used by multiple teams.
• Refactored hot paths and caching to reduce response time.
• Added safer rollout checks for rule changes.

Result

API response time down 10% with safer rule evolution.

Scope & timeline

3 short cycles (~6 weeks).

Before / after

Before: slow responses and risky rule changes. After: 10% faster responses with safer evolution.