From 1995 to March 2000, Ahearn was a director at Credit Suisse First Boston, leading the development of Internet-based applications. At CSFB, he designed, developed and managed electronic trading systems for all the major financial markets. 
From 1987 to 1995, he managed CSFB's Equity Technology group in Tokyo, which built program-trading applications and electronic exchange connections to the major markets in Japan, and established the first straight through processing engine in the Japanese market. Before his assignment in Japan (from 1984 to 1987), he developed personal computer-based financial analysis tools for CSFB.
Prior to joining CSFB (from 1982 to 1984), he was employed by PaineWebber as an internal systems specialist.
- INTERVIEW CENTRAL: Joseph Ahearn, Trading Screen, Inc.. Optionetics.