Most caffeine is found in robust coffee beans - twice as much as in arabica beans. Therefore, a blend that includes robusta, or 100% robusta coffee, or instant coffee (which is mostly made from robusta) will have more caffeine than 100% arabica coffee.
The amount of caffeine also depends on the method of coffee preparation. Caffeine is soluble in water, so the longer the coffee to water ratio, the more caffeine there will be in the coffee. So comparing a small cup of espresso to a cup of coffee in which water was simply poured on ground coffee, the adviser will have more caffeine. Although in the sense of taste it may turn out the other way around.