Logic Masters Deutschland e.V.

Standard sudoku rules apply. Also, a number at either end of a row or column means that there's exactly one pair of adjacent numbers in the row or column whose product equals the number. Furthermore, the pair that gives the product to the left of a row is farther left than the pair that gives the product to the right, and similarly for columns. The two pairs may overlap in one digit.

For example, if there's a 15 on the left and a 12 on the right, then either 5, 3, and 4 occur together from left to right, or else 3 and 5 occur together (in either order) and somewhere farther to the right 2 and 6 occur together (in either order). Note that a row like 534178926 would not be valid, since it has 2 adjacent products equal to 12.

The puzzle is available on Penpa.

I think this is more difficult than Adjacent products sudoku #1 (2020).