Pros
I worked in Tango for a bit less than a year (I had to leave because I've got my dream job in Google, not because I didn't like working in Tango) on H1B visa. Before joining Tango I've read some of the negative reviews on Glassdoor and was a bit hesitant about joining. I'm very glad I ignored all these reviews! My overall experience with Tango was extremely positive: - I've learned a lot of new things in a very wide range of topics and as a result I improved as an engineer tremendously! - I've met a lot of very smart and motivated people and made a lot of friends! - All managers that I was working with (directly or indirectly) were extremely helpful and responsive to my needs! - I had an opportunity to take a peek into insides of a very successful Silicon Valley startup! - Last but not least I should mention all the perks: great food 3 time a day, a lot of team/company events, phone/education/gym reimbursements...
Cons
With more than 200 employees and almost $300 millions of raised funds Tango should already be considered BigCorp for all intents and purposes, not a Startup. And most of the cons in my opinion are strongly tied with the inability to switch away from "startup mode" in which Tango continues to operate: - too much focus on the short-term - inefficient, outgrown code review practices - reluctance, unwillingness of mentoring new people - occasional mandatory work on weekends - a lot of flakiness in the decisions