An employee's experience vastly differs based on what team or organization they work in. This is consistent with other large technology companies.
In the technology-specific functions, some of the downsides include lack of consistent vision and understanding of how your role contributes to overall goals, working long hours, shortage of individual contributors to perform needed tasks, and reduced morale due to a series of re-organizations, re-alignements of headcount, outsourcing, and turnover.
Other employees find that they have difficulty defining what other groups at Expedia do. There isn't always standardization of job functions or transparency in seniority. Lack of documentation or a knowledge base is a common issue across many organizations.