Fix a flaky browser or API workflow without masking the real failure. I reproduce one concrete failure path, harden the smallest boundary, and ship focused evidence. Includes: - Targeted reproduction of a Playwright/API reliability bug - Idempotent retry and state-consistency fix - Regression proof with a browser-visible result plus server-side state - Short handoff with changed files, run command, and limits Best for checkout, cart, admin, and data-entry flows; transient 4xx/5xx responses; duplicate mutations; stale UI state; and .NET, Python, or Node services. Delivery: up to 5 business days after access and acceptance criteria. Fixed price: US$600. Work begins only through Contra's funded/protected checkout. I do not bypass CAPTCHA, MFA, authentication, or access controls.