Hardening API Security in a Large Enterprise Environment

Context

With multiple business units integrating through the API gateway, we identified:

• Missing validation on several critical endpoints
• Weak API key lifecycle management
• Lack of mutual TLS on internal services
• No centralized schema validation

Steps I Led

1. Introduced OAuth2 + JWT for consumer-facing APIs
2. Implemented mTLS for internal service-to-service communication
3. Established schema validation at the gateway level
4. Introduced rate-limiting, quota management and abuse detection
5. Wrote security playbooks and onboarding guidelines

Outcome

• Blocked 98% of invalid or malicious requests
• Prevented 3 high-risk production issues
• Established end-to-end visibility with audit logs & trace analytics

Summary

API security became a first-class citizen, reducing risk significantly across the enterprise ecosystem.