Mission-driven organizations rarely have a technology executive, and rarely have the headcount to add one. A fractional seat gives you the decision-making without a permanent line in the operating budget.
The most useful thing a technology executive can do in a mission-driven organization is usually subtraction: consolidate the tools, cancel what nobody uses, and make the remainder something the team can run without a vendor on retainer.
Every engagement starts with an assessment, whatever the sector. You keep the document either way.