Regulated B2B API Platform

01 / Business Challenge

• Partners followed different integration paths by product line, which increased support tickets and slowed time-to-revenue.
• API keys and tokens were managed in multiple places, so security reviews repeatedly blocked releases.
• Heavy partner traffic caused latency spikes during critical settlement windows.
• When something failed, support could not follow a single partner request end-to-end.
• Auditors expected tamper-evident access history and a clear record of which data crossed the API boundary.

02 / Our Approach

How we executed this engagement in practice. The phases below describe the delivery rhythm we use across ServiceNow, custom engineering, and mobile programs.

We ran this as a platform program: one catalog of capabilities, one partner onboarding experience, and shared ownership across architecture and security. We implemented ASP.NET Core 8 APIs behind Azure API Management (separate API products for external partners and internal teams), used Azure Service Bus for asynchronous settlement and webhooks, and stored secrets in Key Vault. OpenTelemetry tracing fed the client’s existing monitoring tools; staging included synthetic partner load and blue-green releases to reduce cutover risk.

• Designed REST and async patterns (webhooks + polled status) for high-volume partner flows.
• Implemented OAuth2 client credentials with scoped API products and per-partner rate limits.
• Introduced idempotent command handlers and outbox-style publishing for critical financial messages.
• Built a partner sandbox with mock responses and contract tests aligned to OpenAPI specs.
• Automated infrastructure with Bicep and gated production releases behind approval workflows.
• Delivered runbooks and tier-1 triage dashboards tied to trace IDs and partner identifiers.