What is the purpose of Writing Thank You Letter?

It is proper business etiquette to send thank you letters, but many people overlook this matter of courtesy. A thank you letter can make you stand out from the other construction executives competing for jobs, and in this tight job market, it is wise to consider every tool that will give you an advantage.
To be effective, a thank you note should be sent before the hiring decision has been made, so it is best to mail it as soon as possible after the construction interview. When you send a thank you letter, you give the construction interviewer a chance to remember you (imagine having construction interviewed 10-15 construction executives for a position, and then trying to distinguish each one after the construction interviews and trying to remember the specifics about each construction executive). It is your opportunity to mention any important information you forgot to discuss during the construction interview.