We migrated platforms. It took 7 months.

We decided to migrate from one hosting provider to another in January. Planned timeline: 6 weeks. Actual timeline: 7 months.

Month-by-month:

• Month 1: planning, inventory, "this will be easy"

• Month 2: discovered 3 undocumented services nobody owned

• Month 3: migrated the staging environment. It broke in ways production never did.

• Month 4: migrated 40% of production. Rolled back twice.

• Month 5: migrated the remaining 60%. Rolled back once.

• Month 6: the old provider's DNS still resolving for 11% of traffic

• Month 7: final cutover, then 3 weeks of cleanup

Total engineering hours: roughly 640. At a blended cost of $85/hour: $54,400. We had budgeted $20,000.

The lesson was not "migrations are hard." It was that we had no inventory of what we were actually running. Three services had been spun up by people who had left the company. Nobody knew what they did or whether anything depended on them.

Do you have an accurate list of everything running in your production environment right now?