I worked at Kimley-Horn full-time (More than a year)
KHA has a very aggressive business model, that I don't think is sustainable. Every employee is "encouraged" to put in Extra Effort to meet monthly/annual UT goals which doesn't often reflect in bonuses that are mentioned during the hiring process. Although a stable work environment, there is not much room for growth at the staff level. Unless you are willing to work for a paycheck and not have much work/life balance.
On the surface it's a great company with amazing benefits, but it is not a comfortable place to work. KHA is very clever with vesting and can keep you financially trapped. Outstanding 401k match (after 1 year) vested 6 years. Be careful not to get too sucked in unless you know exactly what you're getting into, because it will become harder and harder to leave without leaving a lot of money on the table. And while you're there the KHA machine is squeezing as much profit out of you as possible.