April 21, 2025 5 min read Data Architecture Series: GRAPH Home

Graph Data Architecture: Relationships You Can Query

Graph data is useful when the relationship is as important as the entity. It turns accounts, devices, products, people, and actions into a connected map.

I reach for graph data when the relationship is the question. If the business asks who is connected to whom, how risk spreads, or which path links two entities, I recommend modeling edges as first class data.

The path is the data

The path is the data Graph data shown as a center concept with surrounding signals. The path is the data Graph data Risk or value oftenlives in the pathbetween entities Observed Connected accountsand devices Shape Nodes, edges, labelsand weights Example node_id Handle edge_type

Graph data is the right shape when the relationship is more important than the row.

How relationships reveal hidden behavior

How relationships reveal hidden behavior Graph data as a center asset with surrounding organizational uses. How relationships reveal hidden behavior Shared data asset Account, device, card,merchant, and sharedsignals Source New account uses a knowndevice Find fraud rings Recommend relateditems Explain permissions Trace dependencies

Graph data is the right shape when the relationship is more important than the row.

Where connected data lives

When I talk about "Where connected data lives", I am checking whether Graph Data Architecture can be traced back, trusted, and used by someone making a decision.

Neo4j, Amazon Neptune, Cosmos DB graph APIs, JanusGraph, TigerGraph, RDF stores, graph tables in lakehouses, Elasticsearch for graph backed search projections.

Managed graph options

ProviderTypical services
AWSNeptune, Glue, S3, OpenSearch, SageMaker.
AzureCosmos DB graph APIs, Azure Databricks, AI Search, Synapse.
Google CloudCloud Spanner Graph, BigQuery, Dataflow, Vertex AI, partner graph databases.

Relationship pattern to remember

My recommendation in "Relationship pattern to remember" is to keep the raw source close enough that the answer can be explained later.

Pinterest is a public example: its Taste Graph connects people, pins, topics, and interests so recommendation and advertising systems can reason about relationships rather than isolated rows.

Fraud ring example

I use "Fraud ring example" to keep Graph Data Architecture grounded in a real system, because abstract patterns are too easy to agree with and too hard to operate.

A fraud platform links accounts, cards, devices, addresses, and login IPs. A graph query finds new accounts that share a device with previously blocked accounts within two hops.

Graph review query

I use "Graph review query" to connect the data type to the person, workflow, or system that will consume it.

MATCH (a:Account {id: $accountId})-[:USED_DEVICE]->(d:Device)<-[:USED_DEVICE]-(other:Account)
WHERE other.status = 'BLOCKED'
WITH a, count(distinct other) as blocked_neighbors, collect(d.id) as shared_devices
RETURN a.id,
       blocked_neighbors,
       shared_devices,
       CASE WHEN blocked_neighbors >= 2 THEN 'REVIEW' ELSE 'ALLOW' END as decision;

The query follows shared device relationships, counts blocked neighbors, and returns a review decision. The graph is useful because the risky pattern is in the connection path.

Graph traps to watch

Related graph reads

Written by Arunkumar Ganesan.

What I learnt is that graph systems are strongest when the traversal is a business question, not just a fashionable storage choice.

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