Border Vision
by Jakhob and wooferzfg

Normal Irregular Sudoku rules apply, but the regions must be determined by the solver. All regions are orthogonally connected groups of 9 cells.

A digit in a cell with arrows indicates the number of region borders between that cell and the edge of the grid, totaled across all the directions given by the arrows. The edge of the grid does not count towards the total.

4x4 Example Puzzle
Puzzle Links

Play on SudokuPad

Play on Penpa+