There is a huge list if you will ask me but I will highlight some of them :
1) They treat fresher's (From any reputed institute or from any educational background) as slaves.
2) They verbally commit something else and at the end of the day they will do something else.
3) They don't believe in employee satisfaction at all. (You may exclude the higher management people).
4) HR team needs to be fired. My recommendation is they should study MBA on HR again and understand the true meaning of their job role.
5) Salary is too less as per market standard.
6) Your in hand salary will become a 4 digit number once you will be forced to pay their bond amount.
7) Forget about appreciation for the work you will be doing there. It's a myth.
8) All the engineers and managers and team leads will communicate in their native language...even in meetings.
9) There policies are not transparent. It just keep on changing depending upon the mood of higher management.
10) Management's strategy doesn't looks like that they are willing to form an organization. They are just increasing the market value and finally they will sell out the company.
11) Your seniors (Managers and Directors). You are supposed to address them as SIR/Ma'am. Is this a school or college????
