Pros
Juniper is a place where you will see the most expert Engineers and innovators who are ever ready to share their knowledge. Its a place where there is strong focus in each engineer to make better products than Cisco. More importance and recognition is given to people who innovate and file patents. These are real motivational factors to join juniper though they have a very tough and lengthy interview process. The fact that most people who have interviwed with Cisco and juniper would tell you is , if you can make it through juniper's interview, you can clear any other interview in this industry. Juniper looks at hiring the best people for the job
Cons
Hectic work schedules which means you are working weekends and extending your work on weekdays , especially at the time of releases. There are some teams where you will see some managers who like micro managing things. First level managers are given too much power which is not good.