While black tea has roughly same amount of caffeine as coffee, it's not completely the same for whatever reason. For me double-espresso is more "spiky", has hig

While black tea has roughly same amount of caffeine as coffee, it's not completely the same for whatever reason. For me double-espresso is more "spiky", has higher kick and wears off quicker, black tea has slower ramp up, has longer steady effect, overall leads to better productivity because highs are not as high and tail is longer. Both if taken too late in the day affect sleep. So over time I developed next schedule: double espresso or two in the morning, one or two black teas after lunch/later, decaf black tea or camomile in the the evening.