Left and Joined Back Previous Firm - BGV Advice

Hey Guys!

I was working in a firm from past 2.5 years, left and joined another startup for nearly 2 months as they were providing around 44% hike - Biggest mistake I did, Found culture very toxic, asked my old firm if they still have any opening, left the startup stating not doing health wise.

Now the issue is I want to prepare for FAANG and switch to some good firm after understanding how toxic is startup culture is in India after spending 3-4 months in my current firm. I am only thinking one hurdle which is experience letter for the future firm.

Please advice with your valuable suggestions!