Amazon has lost at least 200 corporate employees who defected to Instacart and Gopuff over the past year as the two delivery players scooped up talent to expand their logistics operations and build out their advertising businesses.

Instacart’s and Gopuff’s hiring, the scope of which hasn’t previously been reported, includes senior-level engineers, advertising executives, European operations leaders and multiple vice presidents. The additions underline how both are looking to tack on higher-margin businesses to loss-making grocery-delivery operations as they eye initial public offerings. They also showcase the fierce battle for tech talent—particularly for companies like Amazon that have seen their stock prices lose momentum, denting prospects for workers’ total compensation.