This is the type of question that doesn't have a simple answer. If the company is in its infancy, there may be cases where developers have to shoulder a lot more responsibility as there isn't the formal safeguards that may exist in a more mature organization that may have a lot more people with roles around them. Consider these 2 examples to contrast the differences in a more clear way:
Organization has 4 developers, a couple of technical support people, and a handful of VPs with various titles like VP Technology, VP Business Development, VP Finance, etc. That's the whole organization. In this case, developers may well be pushing up their own code and having to manage builds, tests, etc. on their own. Here, the developer may not have a mentor and things are very laid-back because there hasn't been any time to formally put in a real process, just ad-hoc, "This works," is adequate.
Organization has 18 front-end developers, a half-dozen testers, a build engineer and others to assist in the overall process. In this case, a developer may have to get manager sign-off before requesting code be promoted and even then that may be done by someone other than the developer in this case. Now, here the developer may have a very specific role on a project initially and may not be given the same latitude as the other case since here the developer is being brought in to do rather specific work.
Both examples are from real places that I did work and it was a day/night difference going from one to the other. Thus, while in the first example a developer may be asked to configure a server, that isn't likely at all in the second case regardless of experience.
To attempt to give a general answer, I think the key is to know how well can the developer take the feature request in a sentence and put it into an existing application. If this can be done well, then more complex requests can be made while if the developer struggles with this, then that has to be where the person is. The number of years experience is different than the developer's maturity with the technology, IMO.