Pete first encountered APL in 1975 when W.S. Atkins made Xerox APL available on their Xerox Sigma 7 & 9 time-sharing service. At the time he was working at W.H. Smith, and used APL to develop several financial planning, budgetary and modelling systems for the Wholesale Division. He was (and still is) attracted to APL primarily by the power it offers to develop highly effective and usable applications quickly. In 1977 he joined Dyadic Systems as an APL consultant, shortly after it was founded by a break-away group from Atkins, where his clients included Rank Xerox, Beecham and British Airways. When Dyadic was acquired as a subsidiary by LynWood Scientific in 1983, he became its Operations Manager, then in 1990, Pete, John Scholes and Pauline Brand bought Dyadic from Lynwood and developed its small hardware sideline into a huge success. By 2000, Dyadic had become one of the leading suppliers of IBM UNIX systems, meaning that the hardware business had totally eclipsed Dyalog APL. In 2002 Dyadic Systems split into two companies – the hardware business continued as Dyadic, and Pete, John Scholes, Geoff Streeter and John Daintree continued to concentrate solely on Dyalog APL as Dyalog Ltd. In 2005, John Scholes and Pete retired from their owner-management roles at Dyalog Ltd, passing ownership and control on to Morten and Gitte.

Pete regards his single greatest achievement at Dyadic/Dyalog as the recruiting of John Daintree, who “has made the most profound impact on the fortunes of the company, starting with our hugely successful interface to the Windows GUI which was released in 1992.”