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Distributed Systems

Building a CDC pipeline with Debezium — without breaking the source

Lessons from tailing a multi-tenant Mongo oplog into Kafka without putting the source database under more load than it already had.

Navneet Lal Gupta

2026-03-20 · 11 min read

// distributed systems

Mongo → Kafka via Debezium

oplog CDC at multi-tenant scale

Stub. Full post body to follow.

The shape of the problem: a multi-tenant Mongo cluster already running at ~70% of its IOPS budget, and a downstream analytics pipeline that needs every change in near-real-time. The naïve thing — polling collections on a timer — pushes load somewhere that has none to spare. Debezium’s oplog tailing approach is read-only from Mongo’s perspective and, done right, costs the source almost nothing.

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