I will investigate one reproducible frontend issue and send a concise written diagnosis within 24 hours after receiving the code and reproduction steps. You receive: the likely root cause with file/line references, steps to verify it, and a practical fix plan or minimal code suggestion. I can review a public repository, a small relevant code excerpt, or a screen share. Please send the exact error, expected vs. actual behavior, steps to reproduce, framework/version, and the smallest relevant files. Do not send credentials or customer data. This is diagnosis for one issue. Implementing and testing a full code fix, backend debugging, and production deployment are separate work. If the issue cannot be reproduced from the supplied material, I will explain what evidence is missing rather than guess.