I would like to add one point : I realised that the working culture, environment and ethics may vary from dept to dept WITHIN the same company, especially bigger MNC companies.

Different bosses / heads of dept may run their dept differently. Some are strict, some are relaxed, some micromanage, some don't. I've also seen and heard of ppl jumping between different dept within big MNC but of course the procedure of jumping dept will vary between companies, so that is another point to consider.