I have been working at Arista Networks full-time (More than 5 years)
Core group is solid. The group that started the company during the first 4 years (2008-2012)? are the smartest in the business. Most departments are flexible in terms of working hours as most employees are mature enough to handle their own time. Bonuses are good if you're lucky enough to be in the right department or you're visible enough. The culture and people are awesome and I wouldn't mind working here til I retire.
A few bad eggs. As the company got bigger, it was inevitable that the quality of employees went down. Don't get me wrong. The company still hires top notch people but a few inept ones eventually get in. Some directors only hire from their previous companies.
Reviews mean nothing. There was once a 360 degree peer review process but I doubt management actually read them. Either that or they just don't care. People who have been constantly getting bad reviews are still with the company, and some people who are constantly getting good reviews don't get rewarded. I'm lucky enough to get raises and bonuses but I know a few people go through 5 years in the company without a raise. Managers get to choose how to rank the subordinates but it seems to be purely at our discretion so I see some actual top notch employees getting left out at other departments.
Inequality between departments. I've been in the company long enough to see that things are improving in terms of overall benefits but there still seems to be unequal treatment for those departments that aren't in Software, Marketing or Sales. I'll leave it at that.
Arista doing so well as a company that it feels like it can get always good employees and not take good care of current ones. It is in danger of becoming similar to Google where the company demands that all employees think that it is a privilege to work there and it would be easy enough to replace you if you leave.
Advice to Management
I've seen it in my 7 years with the company so I'll start with this - When a crucial employee leaves, it is too late to match their salary. It would be good to not cherry pick who gets the ranks. A better review process that involves several levels would help with this.
As mentioned above even though Arista is indeed one of the best companies I have worked for, it needs to take better care of current employees. I've seen so many people leave saying that there is no upside of working at Arista after 4 years if they can get 20% raise somewhere else.
I applied through a recruiter. The process took 1 day. I interviewed at Arista Networks.
One round of interviewing in-person using a laptop. I met a recruiter at a college/university job fair. The interview was not too long. It only took up to an hour and involved only a single question that was not too difficult in terms of task. The main difficulty was just understanding how to use C and being familiar and careful with proper pointer usage as well as pointers to pointers, etc.