Question 1

What can I push into Customer.io from ClickHouse?

Accepted Answer

People and their attributes, custom objects, segments, person events and people devices. Between them that covers what a messaging tool needs: who somebody is, what they did and which group they belong to. Devices are append only, so they are added rather than matched and updated. Everything else follows normal matching, where you map a column from the model to the identifier Customer.io uses.

Question 2

Can I add a new attribute without touching Customer.io?

Accepted Answer

Yes. New attributes and properties can be declared directly in the mapping for people, events and custom objects, so a new column from your model needs no setup on the Customer.io side first. That keeps something like adding an engagement score to one place rather than a coordination exercise across two tools with two owners.

Question 3

Should I send product events through this?

Accepted Answer

It is one of the better reasons to pair these two, since the events are already in ClickHouse at volume. The practical constraint is not the sync but the messaging tool, which is not designed to receive millions of raw events. Aggregate first: send the derived signal, a count over a window or a threshold crossing, rather than every row. ClickHouse is very good at producing exactly that, so let it do the reduction.

Question 4

Who should own creating people?

Accepted Answer

Whichever system genuinely knows first, and the sync mode enforces your answer. Update or create lets the model introduce people, update only enriches existing ones and skips the rest, and create only adds new ones while leaving matches alone. If Customer.io is already fed by your product, update only avoids surprise records. Separately, if a related record in a mapping cannot be found, Customer.io can ignore that relationship and still write the base record.

Question 5

Where should the segment logic live?

Accepted Answer

In the warehouse, whenever it depends on behaviour. A segment defined by what somebody did across sessions, weeks or product areas cannot be recreated inside a messaging tool, and approximating it there produces a second definition that drifts from the first. Reverse ETL moves the result rather than the logic, so the campaign fires on exactly what the model computed.

Sync ClickHouse to Customer.io

Sync ClickHouse to Customer.io with Polytomic

People, events and objects

Declare attributes in the map

Events at event volume

Trusted by businesses worldwide

Step-by-step integration guide

Connect ClickHouse in Polytomic

Connect Customer.io in Polytomic

Create a sync between ClickHouse and Customer.io

Map fields and enable the sync

Frequently asked questions

The sync and ETL platform that does it all

Powerful data sync

Advanced analytics

Enterprise security

Easy setup

Ready to connect ClickHouse with Customer.io?