Pros
I have been working with AST for past 3 years. This used to be Serene Corp before being acquired by AST LLC, HQed in US.
AST is a very flat organization. I've previously worked with most of the bigger companies, AST's work culture is very different. Most of the top leaders in this company take all possible care of employees 'who perform'. I have closely worked with the India head, my VP in US and even company's owner.
There are lots of onsite travel opportunities, even for junior folks, provided they perform well.
There are lot of team building activities and project parties to keep the fun going.
You can easily shift to another technology within the team. Most of the projects are on Fusion Cloud and related tech stack.
Cons
Quality of some of the junior folks is not that great.