Fintech · Community credit union
25-year-old legacy core wrapped in modern APIs — without a rewrite
0downtime during migration
25yrold system, now API-driven
The problem
A 25-year-old core banking system blocked every new product idea. A full rewrite was quoted at 3 years and existential risk.
What we built
Instead of rewriting, we wrapped the legacy core in a modern API layer, then strangled it piece by piece — migrating one capability at a time behind the same interface.
The result
Zero downtime across the entire migration. New mobile features ship in weeks, and the legacy core shrinks every quarter.
Read it on the flight home
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