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Healthcare · MODERNIZATION · 2023
LegacyBridge
A ten-year-old system, rebuilt without ever taking it offline.
Strangler-fig migration done patiently, one endpoint at a time, with the old system as the source of truth until the last week.
Client
Healthcare scheduling vendor
Year
2023
Duration
8 months
Our role
Architecture, migration, mentoring
THE CHALLENGE
The PHP monolith had nobody left who fully understood it. Every change was risky. But it ran 24/7 hospital scheduling — there was no maintenance window to ever take.
OUR APPROACH
- 01Stood up a Node service behind a routing proxy. Old paths fell through to PHP.
- 02Migrated read endpoints first, ran both systems in parallel for two months and compared responses.
- 03Wrote the documentation the original team never had — and trained their two new engineers as we went.
WHAT HAPPENED
Eight months in, the PHP container was decommissioned with no scheduled downtime. The client's in-house team now owns the new stack.
- Scheduled downtime
- 0 min
- Response parity tests
- 12k+
- In-house engineers onboarded
- 2
BUILT WITH
Node.jsTypeScriptPostgreSQLPHP (read)Terraform
IMPACT REPORT
Cutover, one endpoint at a time
Traffic shifted from PHP to Node gradually while parity tests guarded every route.
0 min
Scheduled downtime
12k+
nightlyParity tests run
100%
over 8 moEndpoints migrated
2
onboardedIn-house owners
Share of traffic served by the new stack
Endpoints cut over per month
GALLERY
