Logic Masters Deutschland e.V.

Normal Sudoku rules: Each row, column and 3x3 box must contain the digits 1-9 once only.

Normal Sandwich rules: A number outside the grid is the sum of the digits placed between the 1 and the 9 in the corresponding row or column.

Line rules (equivalent to 9-cell cages): Each blue line must contain all of the digits 1-9 once only.

Normal Kropki rules, no negative constraint: Digits separated by black dots must be in a ratio of 2:1. Digits separated by a white dot must be consecutive. Not all possible dots are given.

Puzzle link: https://f-puzzles.com/?id=yh4us4r6

Solution video: I haven't recorded a solution video for this, but if you'd like one, or just some hints, drop me a line on discord or on twitter @apiyo_dreaming.