The services you rely on.
WHAT TO MAINTAIN
A list of every external service, what it does, and what it costs.
WHAT TO RECORD PER SERVICE
What breaks if it is unavailable Whether an alternative exists Who holds the account What data passes through it Contract and renewal dates
WHY THE FIRST POINT MATTERS MOST
It determines how much resilience is justified.
WHAT TO CLASSIFY
- Critical: the business stops
- Important: something degrades
- Peripheral: barely noticed
WHAT TO DO FOR CRITICAL ONES
Know the alternative, and how long switching takes Build degradation rather than failure Monitor independently
WHAT TO DO FOR PERIPHERAL ONES
Ensure their failure cannot affect anything else.
HOW
Timeouts, circuit breakers, and never in the request path.
WHAT TO REVIEW ANNUALLY
Whether each is still used Whether the terms changed Whether the cost still makes sense
WHY TERMS
Providers change pricing and data practices, quietly.
WHAT TO WATCH FOR
A provider being acquired A provider announcing a new version A provider's reliability degrading
WHAT TO DO ABOUT DEGRADING RELIABILITY
Measure it yourself, and raise it with them.
WHAT TO KEEP
Your own record of their availability.
