How Much Editing Is Too Much?
An editor is supposed to improve your work, but there is a point at which improving it can start to mean writing it for you. For a professional, that distinction can matter. A CV, application, personal statement or professional profile is not simply a document; it may be used to assess the person whose name appears on it.
Correction Is Not Invention
There is nothing unusual about having a CV or application edited. A second pair of eyes may find spelling mistakes, repetition, awkward sentences and information that is difficult to follow. An editor may also suggest moving information, cutting something that adds little or asking whether an important piece of experience has been overlooked.
What editing should not do is invent the missing experience. If you managed two people, editing should not turn that into leading a multidisciplinary team. If you assisted with a project, you should not emerge from the edit having managed it. The finished version can present your experience well, but it still has to be your experience.
Better English Can Change the Impression
If English is not your first language, correcting grammar and unnatural phrasing may make a considerable difference to a document, and that may be exactly why you asked an editor to look at it. How far the editor should go depends partly on what the document is for.
There is a difference between editing a professional biography for a conference website and editing an application for a job in which excellent written English is one of the requirements. In the second case, extensive rewriting could give the reader an impression of your English that the application itself is supposed to help them assess. An editor needs to take the purpose of the document into account.
Personal Statements Need to Stay Personal
Personal statements are particularly easy to over-edit. An editor can point out repetition, unclear passages, weak organisation or a sentence that does not say what you appear to think it says, but they cannot supply your motivation.
A beautifully written explanation of why you want a particular position is of little value if the explanation came from the editor rather than you. The same applies to professional profiles and biographies. Editing can improve the way you express yourself without inventing a more interesting version of you.
Sometimes a Question Is Better
Not every improvement has to be made directly in the text. Sometimes a comment or query is more appropriate: Can you give an example here? Is this the most relevant experience for this position? Do you mean that you were responsible for the project or that you contributed to it?
Those questions identify something that needs attention while leaving the answer with the person whose experience is being described.
It Still Has to Be Yours
When the editing is finished, you should recognise yourself in the document. The English may be cleaner, the structure stronger and something you struggled to express may finally be clear, but the experience, expertise, opinions, achievements and claims should still be yours.
That is the useful boundary: an editor can improve how your professional experience is presented without providing experience, ability or opinions that you do not have.