Most engineering decisions aren't novel — they're variants of forks every roadmap eventually hits. Build vs. buy. One-way vs. two-way. Strangler vs. big-bang. The Playbook is an opinionated set of rubrics for those forks: the criteria that actually decide it, the red flags that mean you're solving the wrong problem, and a default pick when the meeting is going in circles.
Before any other decision criteria — figure out if this is a door you can walk back through.
When the next 'we'll just write a small internal tool' is sitting on the agenda — a four-question filter.
Killing a piece of internal surface area — when, how loud, and what the deadline actually means.
Three honest shapes for any migration. The wrong shape is the most common failure mode.
How much of next quarter to spend on debt — without writing a manifesto, and without backsliding the quarter after.
A piece of work has shown up. Three honest shapes for staffing it — and a default that's right more often than you'd think.