If an employee has gone out of their way to do a great job, here is a sample commendation letter for an employee.
We take immense pride in congratulating you for your utmost dedication and exceptional performance in the past [months/year]. The Department acknowledges your proficiency in handling tasks and your vibrant team-spirit. You have played a commendable role in the previous projects and I have high hopes for your future tasks too.
Thank you for your commitment and keep up the great work!