Before you leap at the opportunity to use Web services, use experience as a guide to possible pitfalls MANAGEMENTSPEAK: We would like this solution to be as flexible as possible. TRANSLATION: Discovering our requirements will be like nailing Jell-O to a wall. — IS Survivalist Joseph Baxter understands the need for flexibility when interpreting conversation. AS PROGRAMMERS AGE, they face age discrimination — true or false? On the surface this appears to be true, but when you accept superficial explanations you pay the price. In my experience, both forward-and reverse-age discrimination are prevalent, except what’s really going on is a mismatch between expectations and you. Managers expect employees to progress. If you’re 55 years old and still want to write code, that’s out of line with expectations. If you’re 23 years old and want to succeed at executive-suite strategic consulting, good luck — gray hair and an exposed scalp are unstated but vital qualifications. When it comes to evaluating Web services, the latest Next Big Thing in IT, gray hair and an exposed scalp helps. Assuming, of course, that history serves as guide to the future. For example, the vision of Web services is that you’ll assemble any application you like by stringing together publicly available components from multiple vendors. Using standard interfaces and ubiquitous Internet protocols will make this fast, cheap and easy. But don’t bet the farm. It could happen, I suppose. You just have to expect a few miracles. Software vendors could shift their support policies 180 degrees. Right now, if you have just two vendors and one problem, you solve it yourself, because your vendors expend all of their efforts pointing fingers at each other while telling you they don’t support your configuration. Vendor and product selection might become quick and simple. Right now the process of selecting a software package from a single vendor requires serious effort. With Web services you’re assembling your application from the work of dozens of vendors. In my experience, comparing multivendor solutions is more complicated than single-vendor solutions, not less. Humanity might become completely trustworthy. At the recent InfoWorld Next Generation Web Services Conference, a security panelist made a telling point: Just because a component advertises its behavior through UDDI (Universal Description, Discovery, and Integration) doesn’t mean it’s telling the truth. Even ignoring the likelihood of malfeasance, we’ve all encountered DLLs that don’t behave as advertised. Why should publicly available components be any different? Hmm? Web services is a promising architecture. Many of us expect it to be important in the not-too-distant future. The tricky thing about the future, though, is that it hasn’t happened yet. The best guide we have is history. So far, the Web services hype factory has ignored its lessons. Software Development