Enterprise integration patterns, choreography vs orchestration, canonical data models, and adapter design for complex financial ecosystems — with the runtimes that implement them in production.
The single most under-implemented pattern in financial-services APIs: key design, storage trade-offs (Redis vs Postgres vs hybrid), TTL and eviction, request-fingerprint matching, replay semantics, and the production failure modes that turn a retry into a duplicate payment.
The EIP catalogue applied to production: content-based router, message translator, splitter, aggregator, and how IBM App Connect Enterprise implements them in real flows behind the bank.
Camel K and Camel Quarkus on Kubernetes, route design, and the open-source alternative to commercial integration platforms.
Mapping legacy MT messages to ISO 20022 pacs.* and pain.* flows, validation strategies, and the migration paths regulators expect.