An application-specific integrated circuit (ASIC) is customized using two non-adjacent via layers. An array of logic cells, each including a plurality of logic devices, are arranged in a plurality of non-customized base layers. A first routing grid, which includes a first non-customized metal routing layer, a customized via layer, and a second non-customized metal routing layer, is disposed on top of the plurality of non-customized layers. A second routing grid, which includes a third non-customized metal routing layer, another customized via layer, and a fourth non-customized metal routing layer, is disposed above the first routing grid. A non-customized via layer is disposed above the first routing grid and beneath the second routing grid. The routing grids and the non-customized via layer collectively facilitate routing connections to and from the logic cells.