Customer 360 & Real-Time Risk Intelligence Platform  ·  View 19 of 20

Card Transaction Event Sequence

The ordered message exchange for a single card authorisation, from switch to fraud decision, including the schema-rejection path.

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Card Switch
Card Switch
Event Gateway
Event Gateway
Kafka
Kafka
Flink Enrichment
Flink Enrichment
Profile Store
Profile Store
Bronze Lakehouse
Bronze Lakehouse
Fraud Service
Fraud Service
1. authorisation event
1. authorisation event
2. mTLS + schema validate
2. mTLS + schema validate
3. produce txn.auth.v2
3. produce txn.auth.v2
4. invalid to DLQ
4. invalid to DLQ
5. consume by customer key
5. consume by customer key
6. dedup on event id
6. dedup on event id
7. lookup 360 profile
7. lookup 360 profile
8. profile + features
8. profile + features
9. derive velocity signals
9. derive velocity signals
10. publish enriched event
10. publish enriched event
11. sink raw + enriched
11. sink raw + enriched
12. enriched.txn.v1
12. enriched.txn.v1
13. approve or challenge
13. approve or challenge
14. decision outcome
14. decision outcome
Card Transaction — Event Sequence
Card Transaction — Event Sequence
Happy path plus schema rejection. Retry, rebalance and backpressure paths are omitted.
Happy path plus schema rejection. Retry, rebalance and backpressure paths are omitted.
v 1.0 · owner Risk Data Engineering · date 2026-08
v 1.0 · owner Risk Data Engineering · date 2026-08Text is not SVG - cannot display

What this proves

  • The 2-second budget is achievable with one profile lookup and no synchronous lake read
  • Validation happens at the edge, before an invalid event can pollute a topic
  • Raw and enriched payloads are both persisted, so the decision is reconstructable

Deliberate omissions

  • Consumer rebalance, retry and backpressure paths are not drawn
  • Detokenisation calls are omitted; they occur only in the fraud service under policy
  • Batch reconciliation of authorisations against settlement is a separate flow

Failure behaviour

  • A schema-invalid event is dead-lettered; the switch still receives a decision
  • If enrichment is unavailable, the fraud service scores on the raw event and degrades gracefully
  • No platform failure blocks a card authorisation — the risk path fails open by design
Solution Architecture v1.0 · Enterprise Data Architecture · 2026-0819-transaction-event-sequence