The cost of living in Singapore is 1000 - 1700 SGD for a small room - you will not be able to afford a studio apartment on your paycheck of 4500 SGD. Teachers salaries have not been increased in ten years. There is no room for advancement and chances of a raise are slim to none.
Hours are opposite to all other company hours as this is an after school programme. Therefore, it will be very difficult to make friends beyond your coworkers.
The work is repetative - sometimes you teach the exact same lesson three to four times in a row depending on what classes you have. This is absolutely mind-numbing by the time you fulfill your two-year contract.
No matter what they tell you during the interview, you will be teaching children aged 2.5 - 12 years of age.
Many of my friends experienced verbal attacks from parents and were given no assistance by their centre managers.
Employees used to be required to come in a half hour before their classes started but now a 1pm - 9pm weekday schedule has begun to be implemented. You will have no mandatory work to do before your classes start and will often sit in an empty classroom for 2-4 hours. If you question this, you will be provided with "busy work".
Worst for last, members of upper management are blatantly racist, going so far as to insinuate teachers of non-white or non-Chinese decent "taint" the centres.
In conclusion, never forget this is a private company who values money over its employees well-being.