Like almost any good legal question, the answer is "it depends." Generally, an individual person can be given the ability to hire and fire employees without calling for a board vote. But a more specific answer is that you should look at your association's bylaws. Under Maryland law, the "council of unit owners" has ultimate responsibility for conducting the affairs of the condominium. But the council is permitted to delegate its powers to a board of directors or officers.
And there are required to be bylaws: "the administration of every condominium shall be governed by bylaws which shall be recorded with the declaration." There are some things that are required to be in your bylaws, including: "whether, and to what extent, the duties of the council of unit owners may be delegated to a board of directors, manager, or otherwise, and specifying the powers, manner of selection, and removal of them." In addition, the bylaws "may" also include "any other provision regarding the management and operation of the condominium."
So, in Maryland you have the "council of unit owners" who represent the largest group and includes all unit owners. But you generally don't want every decision to be something that the entire council votes on. Can you imagine if all of the owners had to assemble (with a quorum) to vote on every decision that affected the association? So your bylaws set out the categories of things that are delegated from the council of unit owners and to the board and to the officers. Many such organizations will specify that the board has to vote to make a decision to hire and fire certain key employees, but that other minor positions can be hired and fired by some other person, perhaps (in your case) the president.
So, look to your bylaws for the answer to whether, in your case, the president has been delegated the authority to hire and fire. For that matter, look to your bylaws to see whether the board of directors has been delegated that authority. Hopefully not, but it's always possible that your bylaws are missing something that gives that authority to somebody. In that case, the authority to hire and fire might still be sitting with the council, the entire slate of unit owners.