August 20, 2009
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The Economics of Speed

I’ve been working long hours lately, moving Tinderbox to a new development platform with new compiler and new libraries. This pays down some accumulated technical debt, and the need to examine every object and every file helps build a cleaner system. But the main benefit you’ll see immediately is speed.

Part of the speed boost will come from having a universal binary. Lots more comes from careful revisions, such as finding ways to do less work when loading and saving files. Lots of this is expensive; it's easy to spend several thousand dollars to save a few seconds.

Is it worthwhile?

The stock answer is, “Of course! Nothing is too good for customers, user experience is crucial, and speed makes the experience better.” But that’s wrong. User experience is not what matters: getting your work done is what counts. Getting the book written, getting the plan approved, getting the right answer – all of these matter a lot more than a few seconds here or there.

But seconds do count. If we can make Tinderbox load faster, that saves only a few seconds — but it saves those seconds many times a day, for many people. Perhaps none of those people really care about saving those few seconds. Perhaps none of them would pay to save them. But, in aggregate, it can make sense for them to pool together and invest a few thousand dollars because, in aggregate, it’s worth it.

But it’s not an easy call. Lots of businesses get this wrong, investing in over-engineered products when the customer would prefer to save the money. Business presentations are a conspicuous example: people spend a fortune on fancy PowerPoint decks that nobody needs to see. Books, too, have long been over-engineered: the history of the late 20th century demonstrates how readers, given the chance, prefer to keep the money at the cost of less perfectly-produced books and newspapers. (Magazines, on the other hand, seem to thrive on production value; as the paperback and DocuTech have flourished in the book world, the pulp magazine has pretty much vanished.)

Update: a sensible response from Loryn Jenkins, who is more concerned with “flow” state and less worried about the economics of temps perdu. Another developer wrote a convincing email to argue that most software managers actually undervalue both user experience and freedom from technical debt.