Context & Challenge
12 years of integration debt, one migration
The client's BizTalk Server installation had been in production for 12 years and was processing 2.3 million messages per day across 47 integration flows connecting ERP, WMS, POS, e-commerce, and supplier systems. BizTalk 2013 was end-of-life, the sole BizTalk developer had left the company, and the system was operating without documentation.
The risk profile was severe: any approach that required a full cutover — migrating all 47 flows simultaneously — had an unacceptable downtime risk. The business operated 24/7 across 340 retail locations and could not tolerate an integration outage of more than 15 minutes.
Our Approach
M1
Discovery: Reverse-engineered all 47 BizTalk orchestrations into documented integration flows. Classified by risk and business criticality. Identified 12 flows suitable for immediate migration, 23 for mid-programme, 12 high-risk flows for final migration.
M2–3
Infrastructure: Kafka cluster deployed (MSK), schema registry configured (Confluent), Symfony Messenger transport configured. Strangler fig routing layer deployed in front of BizTalk — all traffic still going to BizTalk.
M3–8
Flow migration: 47 flows migrated in four waves over 6 months. Each flow: build, shadow mode (parallel with BizTalk), comparison validation, traffic switch, BizTalk route disabled. Full rollback available in 30 seconds on every flow.
M9
BizTalk decommission: Routing layer removed. BizTalk Server decommissioned. Schema registry publishing established for all active producers. DLQ + replay API deployed for all consumers.
Outcomes
60% reduction in average integration latency (synchronous polling replaced by event-driven push)
Zero downtime at final BizTalk cutover (strangler fig enabled per-flow routing)
All 47 flows migrated in 9 months against a 12-month target
100% of flows have dead-letter queue, three-tier retry, and replay API
Schema registry enforcing backward compatibility on all 47 producer schemas
Internal team trained and operating the new platform independently
Technology Stack
Engagement lead: CELESDEV Solutions — Integration & Data Practice. Reference call available on request under NDA.