Jan Jacobs de Molijn
In some records, he is referred to as Jan Jacobs de Molijn the elder (de oude) to distinguish him from his son Jan de Molijn the younger (de jonge), who was a notary. His other son Jacobs Jans married Leeuwenhoek's widowed mother in 1640.
When he died, he was living on the north side of the Choorstraat, for which he paid the hearth tax (haardenstedengeld) in 1600 for five hearths (fireplaces).
Some records note that he was a deurwaarder, literally a doorkeeper. He was probably something closer to today's bailiff or process server.
One of his official duties is noted in OAD inv. 871 Bestek voor het maken van houten platingen in de Buitenwatersloot met rekening van Jan Molijn als ontvanger van de collecte voor de platingen, 1602-1614. That translates literally as "Plan for making wooden sheet-piling in the Buitenwatersloot with the account of Jan Molijn as receiver of the collection for the sheet-piling". Or this Jan Molijn could have been his son the notary.