Agent WranglersTKO-13Avoid
Freezing the old system for a big-bang rewrite
Never stop work on the old system to rewrite all of it and switch every user over on one day.
How to do it
The old system keeps changing in the business's head while the rewrite chases it. Months pass with no fix shipped, and the switch day finds every difference at once. AWS calls a big-bang migration a transformation risk that makes adding features hard or impossible. Move one part at a time instead, as Put a router in front and move one route at a time says.
How to check
The migration plan lists each part with its own switch date, and no single date moves every user at once. The old system has at least one shipped change in each month of the rewrite.
Sources
Related rules
- TKO-15 Put a router in front and move one route at a time in Codebase takeover
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