What is a less cumbersome way to say "acknowledging of hard work"?

Solution 1:

You could use the word kudos.

Solution 2:

Recognize their contributions?
Commend their good work?
Praise their efforts?

I'm not sure how concise one can make this.

Solution 3:

We used to have the informal notion of an "attaboy" as a verbal or written acknowledgement of work well done.

Solution 4:

“(To give) credit where credit is due” is a fairly well established idiom, close to what you’re asking for, and used sometimes in management contexts:

A fair man, he liked to give credit where credit was due. [Source]

It is not difficult to get executives to give credit where credit is due — provided that is basically the desire of top management. [Source]

Solution 5:

we used to say Bravo Zulu for a job well done

Bravo Zulu is a naval signal, conveyed by flaghoist or voice radio, meaning "Well Done"; it has also been used as part of vernacular slang