It appears that the sides of the sink butt to the sides of the countertop with a topical silicone joint between them. This is a disaster waiting to happen. The silicone seal will inevitably fail, get contaminated with black mildew and leak. Even if the contractor provided the sink manufacturer's installation instructions showing this detail, it would be wrong.

What is the dark line between the countertop and sink just above the rack please? It appears to be a void. See if you can stick a knife in there please.

The only cost effective way I can see out of this without replacing the top is by replacing that sink with a sink the same size as the cabinet with a sink flange that goes under the top that has a proper silicone seal. A positive reveal is fine. Something like this please.

The eased pencil edge at the sink cutout isn't even as large as the radius on the rest of the top. That sharp edge at the sink is a chip factory, I promise. Have them re-profile and polish it before the new sink is installed please; 1/4" minimum.

Furthermore, they've made the mistake of bringing the white silicone color of the sink to the countertop. Using a translucent white silicone or clear, you should bring the color of the top to the sink for the best looking job.

We haven’t installled flange yet or any of the plumbing just the sink. Not sure what you mean by a “sink the same size as cabinet” it’s an apron sink and you have to fit it inside the cutout. I agree that something look off with the edge of countertop near sink.

I agree with Joseph. A sink needs to be either undermount (with the silicone joint above the sink, touching the underside of the countertop) or with a flange, sitting on top of the countertop (and silicone underneath the flange, above the countertop). You should not have a vertical silicone seal around a sink. The hole for your sink was cut too larger for your undermount sink. That is why Joseph is suggesting you get a larger sink.

So basically they did the under mount incorrectly?

Not sure how much bigger I can get the sink it’s only about a quarter of inch on each side that was filled with silicone

Are you both saying They have to make the cutout bigger and we have to buy a larger sink so it can go underneath better

Cutout for cabinet

Yes, it is undermounted incorrectly.

You don't install a flange; the flange is integrated into the sink.

Let's assume your cabinet is 36". The 36" Kohler Whitehaven I linked to will mount into the existing cabinet; the apron will extend almost to the end of the cabinet styles. Now the ends of the doors and the end of the apron align, which I think looks better anyway.

The cutout does not have to be enlarged. What is the distance from the cabinet front to the rear of the cutout please?

I don’t see any links Joseph, could you share again. Is the only way to get undermount look is to cut a new slab?

Thanks in the tips Joesph, contractor is getting a new slab due to quality of slab in certain places and will cut again making sure it’s undermount

Here is the link from Joseph, below. It's also linked from his text "Something like this please." (For some reason if you're on your laptop vs in the phone app, Houzz no longer highlights links in green. At least not for me when using Chrome.)

https://resources.kohler.com/webassets/kpna/catalog/pdf/en/K-6489_spec_US-CA_Kohler_en.pdf

Much better, but a more rounded edge profile at the sink would be less likely to chip. That pencil is nearly a guarntee. Thankfully, no white cauld at the notch.