Pros
A large company with a good balance sheet that keeps people steadily employed. Can work on interesting projects if you network well within the company. Work place conditions are often pretty laid back, business casual or less required. Company is well known amongst others within the A/E community, good professional respect from colleagues elsewhere.
Cons
Tetra Tech is a big company comprised of many acquisitions and each company operates separately. Incredibly frustrating to be chasing same clients within the same geographic area and management has absolutely zero interest in changing this culture. For over 10 years the company has does absolutely nothing to better integrate all the individual companies. When visiting an office in a new location you are treated like a visitor from a competitor and not at all part of the same company. Transferring to a different office is like applying for a new job. All the various P&L centers hoard work and will use your qualifications to win work that they have no intention of sharing with you. Salaries at Tetra Tech are definitely on the lower side in the industry and time office allowance is ridiculously limited.