As an engineer I can say it can be a "hurry up and wait" kind of job. Around the 20% mark of a project timeline I'm 80% finished but then have to rely on a non-responsive authority to answer me back over some obscure part of the project. After that I just nag them and the project manager about it in email to cover my ass then do fuck all until they respond. At the 95% mark they answer back and I have to hurry up to finish. It can be stressful at times but it's not bad otherwise.