Stewart K. answered 10/10/21
AP, Research Paper, and Classroom History, Gov, and Geo Tutoring
The federal rule-making process includes a period for public comment. However, it is unusual for agencies to get comments from the general public; mostly this is an opportunity for lobbyists to weigh in. However, if there is a big public campaign by some interest group around a proposed regulation, there could be many public comments. Here's a website explaining the federal rule making process: https://www.regulations.gov/learn
There are also federal agency employees (members of the executive branch) who exercise a quasi-judicial authority and can set precedent for others to follow (including the court system, sometimes). These include consuls and CIS adjudicators in immigration matters, tax court judges, and a variety of regulators.
We are very familiar with the federal courts' power to overrule laws passed by Congress and signed by the president as unconstitutional - this is not exactly legislating, but it is a form of veto on legislation. Judges will sometimes act as regulators, particularly when implementing a very complex decision. An example would be the school desegregation cases during the civil rights era: federal judges would have years-long executive responsibilities for overseeing the management of school districts that were being forced to desegregate.