Darwen worked from 1967 to 2004 at IBM. He was from 1978 to 1982 chief architect for the Business System 12, a database system that would implement the principles of the relational model with high fidelity. During this time he worked closely with Christopher J. Date and represented IBM in the SQL committees of the ISO ( JTC1 SC32 WG3 Database languages , WG4 SQL / MM). Since 2011 he teaches at the University of Warwick, Department of Computer Science and is a tutor at the Open University. He lectured there on the language Tutorial D, which he developed together with Chris Date. His early works he published under the pseudonym Andrew Warden, both an anagram of his surname.
In addition to his work on databases, he has written a book about the card game Bridge and runs a website on this topic.
- CJ Date, Andrew Warden: Relational database writings, 1985-1989, Volume 2, Addison -Wesley, 1990, ISBN 0201508818
- Chris J. Date, Hugh Darwen: SQL standard: SQL/92 with the extensions CLI and PSM, Pearson Publishing Germany GmbH, 1998, ISBN 3827313457
- Hugh Darwen, Chris J. Date: Relational Database Writings: 1994 - 1997, Volume 4, published by Addison -Wesley, 1998
- Darwen: Magic Bridge, Publisher Faber and Faber, 1973, ISBN 0571102506