Gulsen Onsoz -
However, "Önsöz" translates to "Preface" or "Foreword" in Turkish. It is possible you are looking for:
If you are referring to a "draft feature" in the context of a person named Gülşen Önsöz (who may be a designer or developer), there is no widely documented public profile or feature associated with that specific name in the tech or design industry based on current public data. Gulsen Onsoz
The title track, "Önsöz," was written and composed by Gülşen and produced by Ozan Çolakoğlu. However, "Önsöz" translates to "Preface" or "Foreword" in

