Is it impermissible (haram) or permissible (halal) to act as an intermediary between a job seeker and employees on a website, such that a company or individual requests a design, then employees express their desire to create this design, and the intermediary website selects the employee?

There is no objection to subscribing to the website if its function is merely an intermediary between a job seeker and someone who wants it done, because it is a brokerage or agency, neither of which is objectionable. A woman working in her home in permissible matters is among the most befitting and suitable occupations for her, due to the absence of mixing with men, leaving the house, or neglecting responsibilities.