Secure API gateway and integration layer

The challenge

An enterprise with over 60 internal services and a growing partner ecosystem had no consistent approach to API security. Some services used API keys stored in environment variables, others used OAuth with varying configurations, and partner integrations relied on IP whitelisting with shared credentials. There was no centralised audit trail for API access, making compliance reporting a manual, error-prone exercise.

A security review had flagged the integration layer as a critical risk. The organisation needed a standardised gateway that could enforce authentication and authorisation policies without requiring every service team to reimplement security controls.

What we did

Phase 1 — Integration audit. We catalogued all service-to-service and partner integrations, documenting authentication methods, data classification and traffic patterns. We identified 14 integration patterns that could be consolidated into four standardised flows.

Phase 2 — Gateway architecture. We designed and deployed an API gateway layer that handled authentication, rate limiting, request validation and audit logging. The gateway supported multiple authentication methods to allow phased migration — teams could move from API keys to OAuth tokens at their own pace.

Phase 3 — Policy engine. We implemented a policy-as-code engine that enforced authorisation rules based on service identity, data classification and request context. Policies were version-controlled and reviewed through the same pull request workflow used for application code.

Phase 4 — Partner onboarding. We built a self-service partner portal for credential management, API documentation and usage monitoring. Partners could generate credentials, view rate limits and monitor their consumption without requiring manual support from the platform team.

Measurable results

Compliance reporting went from a multi-week manual process to an automated report generated on demand. The security team gained real-time visibility into all API access patterns, and partner onboarding dropped from weeks to days.