Marina Escolano-Poveda from the University of Liverpool wrote an ARCE article entitled: "Imhotep: A Sage between Fiction and Reality"(https://www.arce.org/resource/imhotep-sage-between-fiction-and-reality).
In her attempt to sort out what is known and what is lore, she makes the following statement: "These titles call Imhotep the royal seal bearer and great of seers (priest of the temple of Heliopolis), as well as overseer of sculptors. There is no explicit mention of his role as architect of Djoser’s pyramid complex."
And this is where the problem begins and ends with a fascinating connection, Wolfgang Helck pieced together over thirty years ago (Untersuchungen zur Thiniteszeit. Harrassowitz Verlag, 1987). Escolano-Poveda forgot to mention an important detail.
The title "great of seers" is actually He who sees the Great One, m33w-wr ; The Great One is Horus and one of Horus' manifestations in the sky was Sirius, the bright star in Canis major. There were other Horus forms which were likely the planets Mars and Venus, but this is another topic. The title first appears in the First Dynasty and was conferred onto princes who supervised royal building projects, for example Fourth Dynasty Prince Rahotep. The way Helck pieced this together is what Egyptologists normally do when they do not have a direct translation: They develop the context around the title. In this case, the other titles held by those princes had to do with expeditions, supplies, and building. A related title is m33w-mnw, for example, He who (over-) sees the Monuments.
The connection between astronomy and monumental building is relevant to ancient Egyptian architecture, because the sky mattered in the design of temples and pyramids. This connection is reflected in the title m33w-wr .
There was a general tendency for concrete functional titles given to officials in charge of food production, transportation, and other supply procurement to be converted to ceremonial titles given as tokens to high officials not active in the duties designated by these titles. The recipients commonly were temple priests. In this particular case, however, the title m33w-wr was converted to the High Priest of Heliopolis. Wolfgang Helck reconstructed this conversion by pointing out that stone quarries at Heliopolis were near the Temple of the Sun and so the title naturally migrated due to this physical proximity.
However, the bridge between astronomy and construction is at least as likely I think, if not more so. In any case, in the case of Imhotep, he appears to indeed have been the overseer of royal works certainly implicating him as the designer and builder of the Step Pyramid.