The HTTP status code 502 Bad Gateway is likely to be encountered in scenarios where the API Gateway serves as a proxy and receives an invalid response or no response from the upstream server, which in this case is the Lambda function. This can happen if the Lambda function is not configured correctly in API Gateway or if it does not exist. The 404 Not Found status code indicates that the requested resource (such as a URL) could not be found, but in the context of API Gateway and Lambda, it is more typical for a 502 Bad Gateway to occur due to misconfiguration. Status codes 400 Bad Request and 500 Internal Server Error represent different categories of errors and are not directly associated with the specific scenario described.