API & SaaS Integration Diagnostic | REST, Webhooks, Auth

API failures are often narrow but expensive to guess at. I focus on one clearly defined failure path at a time: reproduce it safely, compare expected and observed behavior, classify the strongest root-cause hypothesis, and document the next reversible change and regression check. The work can cover REST, GraphQL, webhooks, authentication schemes, headers, status codes, schemas, retries, and API-to-SaaS data mapping.\n\nThe diagnostic is intentionally bounded. I do not request credentials or raw private payloads before funding, do not make production changes, and do not promise an open-ended implementation. The attached portfolio item is an internal technical demonstration of a fixture-first Python diagnostic harness; it is not a past client engagement.

Work Terms

Available for one bounded diagnostic slice at a time. Typical delivery target: 24–48 hours after written authorization and a funded milestone or prepayment are confirmed. Public-safe/local fixtures and redacted evidence only before funding. No credentials, cookies, raw private payloads, or unapproved production environments before the authorization and funding boundary.