People only vote for local representatives. Those local representatives choose an executive for their area, who manages the government for that level. Those local representatives vote for representatives that cover a larger area the government of which has different responsibilities than those of the local group. Form as many levels as is reasonable, with each level having different responsibilities regarding governance, presumably those suited towards the size of the area that they oversee. Stagger elections such that there is a long time between the election of a level of representatives and the election of the next highest level, meaning that the goal is good governance at the level they are being elected for, not to push their agenda up to the higher level. Each representative, in casting their vote for the next highest level or for exectuive, casts a number of votes equal to the number of votes they received when elected. They may choose to split these votes among favored candidates, even for the singular executive position.
Candidates for higher level representatives may be considered that are not currently representatives doing the voting, but they will be required to have at least once been elected to the level just below the one they are standing for. Executives for each level of governance need not be chosen from among the representatives elected for the assembly of that level, but each executive would need to have served as executive of at least the next lowest level for a full election cycle.
Vacancies in executive posts are interimly filled by the representative for that level with the most experience as an executive, with higher level experience trumping any amount of lower level experience. If no representatives have any executive experience, then repeat with experience as a representative. In case of a tie, there will already have been a draw at the seating of the representatives to randomly determine which one has precedence. This is done for all representatives with precedence ties so that there is a clear order of succession. A new permanent executive is to be chosen as soon as possible.
Vacancies of representatives are filled by taking the person who had the next highest vote total among those not chosen for the assembly originally.