Book Review: Kill It With Fire - Manage Ageing Computer Systems by Marianne Bellotti

Computers, eh? Leave them for five minutes and they become obsolete. Leave them for five years and they become legacy infrastructure. How do we deal with a tower of "quick fixes" which are older than Moses? What strategies do we need to stop teams going mad as they try to upgrade a Spitfire into a 747 while in flight?

This is Marianne Bellotti's attempt to explain how we get there and - just maybe - how we stop legacy cruft from building up in the first place.

I found myself highlighting every other page. It's chock-full of wisdom and endlessly quotable. Perhaps a few of the tales verge on the "Just-So" story - but we all need little morality tales to remind us how we should behave.

Ultimately, of course, this isn't about computers:

Overall, interfaces and ideas spread through networks of people, not based on merit or success.

There are some harsh words for programmers and systems architects:

Engineers tend to overestimate the value of order and neatness. The only thing that really matters with a computer system is its effectiveness at performing its practical application.

And

The lesson to learn here is the systems that feel familiar to people always provide more value than the systems that have structural elegances but run contrary to expectations.

Ouch! Harsh but fair.

It is a relentlessly pragmatic book. The author outlines what works, what doesn't, and why things happen. Keeping up the moment of success is the only way to stop a team from collapsing in despair. And the only way to stop a system collapsing into dust.

Humans built these systems. It takes human will, passion, and ingenuity to re-build them. We may think that we want the replacement to be harder, better, stronger, faster. But what our users crave is stability and predictability. Never lose sight of that.