Simplify the following text for a Grade 11 native English-speaking person.
Original: Joining the Vereenigde Oost-Indische Compagnie ( VOC ) Dutch East India Company in 1639 , he served in a number of posts , including that of an assistant surgeon in the Batavia in the East Indies .
Simplified: Joining the Dutch East India Company ( VOC ) in 1639 , he served in many posts , like an assistant surgeon in the Batavia in the East Indies .