Strangler migration plan
Design a strangler-fig plan to migrate a .NET Framework 4.8 IIS monolith to .NET 8 without big-bang rewrite.
Answers use simple, clear English.
Quick interview answer
1) Inventory dependencies (System.Web, WCF, EF6, Windows auth). 2) Introduce reverse proxy/YARP/IIS ARR routing. 3) Extract highest-value APIs to .NET 8 first.
Detailed answer
1) Inventory dependencies (System.Web, WCF, EF6, Windows auth). 2) Introduce reverse proxy/YARP/IIS ARR routing. 3) Extract highest-value APIs to .NET 8 first. 4) Shared DB with expand-contract schema. 5) Move auth to token/cookie compatible model. 6) Retire Web Forms modules last. 7) Contract tests + feature flags + parallel run. Target LTS (.NET 8).
Real example & use case
/api/orders traffic shifted to Core 8 service while UI remains Framework temporarily.
Pros & cons
Pros: continuous delivery, lower risk. Cons: dual-running cost and routing complexity.