Kill It with Fire: Manage Aging Computer Systems (and Future Proof Modern Ones)

by Marianne Bellotti

This is a book about how to run legacy modernizations, a topic many software engineers regard as slow-moving career suicide, if not the prologue to a literal one.

Tightly coupled systems produce cascading effects.

Tightly coupled and complex systems are prone to failure because the coupling produces cascading effects, and the complexity makes the direction and course of those cascades impossible to predict.

Tests tell you only what won’t fail; monitoring tells you what is failing.

overgrowth is not technically hard; it is just frustrating and demoralizing.

If you’re thinking about rearchitecting a system and cannot tie the effort back to some kind of business goal, you probably shouldn’t be doing it at all.

but the number-one killer of big efforts is not technical failure. It’s loss of momentum.

Being strategically narrow-minded to demonstrate value and build momentum is not a bad idea.

At small organizations, we find people are doing several different jobs at once with roles not so clearly defined. Everyone in the same space is using the same resources. In short, small organizations build monoliths because small organizations are monoliths.

nothing says you’re serious about accomplishing something more effectively than changing people’s scenery.

First, you define your goal, and then, you define how you’ll know that you’ve reached your goal. Except, OKRs usually focus on signs that the goal is completed, and success criteria should focus on signs that you’re heading in the right direction.

Working groups are typically initiated and staffed by people on the implementation layer of the organization.

When in doubt, default to panicking. It’s more important that errors get noticed so that they can be resolved.

successful complex systems are made up of stable simple systems.

Shipping new code gets attention, while technical debt accrues silently and without fanfare. It’s not the age of a system that causes it to fail, but the pressure of what the organization has forgotten about it slowly building toward an explosion.

This is not the work of technical janitors, but battlefield surgeons. It has been the greatest honor to serve among them.