Google created its own Web server instead of using the open source Apache Web server, which underpins more than 60% of Web sites. Google's Web server can run on more machines and balance workloads among servers more effectively than Apache for Google's large code base, which contains lots of dependencies among programs, DiBona says. The company's approach to software like the Common Gateway Interface standard for linking databases to dynamic Web pages may be harder to use than with Apache, but it runs faster. "If we can eke out 10% to 20% better performance, we can save a lot of power, AC, and people," DiBona says.
A tracking system automatically pulls information on job applicants, gives a hiring manager a job candidate's resumé, offers questions to ask, and sends the manager an e-mail after the interview asking what he or she thought of the candidate. Job interviews can involve logic questions, writing code, talking about software architecture, and generally proving to Google's brain trust that the applicant is a fast learner, since the company doesn't keep people working on the same problems for very long.