The key question is what strategy this development executive is supposed to execute. Once you have a good understanding of the strategy (the perfect case is to have a strategy map), then KPIs will come naturally. Without understanding of the strategy and business context, it is impossible to recommend something.
Just as an example, here are some KPIs for HR training, but I’d recommend to be clear about the strategy first.
What are the possible KPIs for a Business Development Executive in an e-learning startup?