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Business productivity ⇄ Human resources

Customer.io to Greenhouse integration — real-time, two-way sync

Keep Customer.io and Greenhouse in sync without custom scripts. Cut weeks of integration work, eliminate silent data drift, and give your team a single, reliable source of truth.

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Adopted by fast-scaling companies moving mission-critical data in real time

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Why teams connect Customer.io and Greenhouse

Keep the people, teams, and status that Customer.io and Greenhouse share aligned in real time, so a hire, role change, or departure recorded in one reaches the other within seconds.

Each tool in Customer.io keeps its own list of who can use it: users, members, or agents, along with the team they sit on and whether they are still active. Greenhouse is the authoritative record of the same people as employees, with their department, manager, and employment status. When those two are connected only by manual account admin or a periodic export, the work tools drift: new hires wait days for access, team and manager changes never catch up, and people who have left keep standing accounts.

Stacksync syncs Deliveries / Messages, Newsletters, People, Objects in Customer.io with Offers, Scorecards, Scheduled Interviews, Users in Greenhouse bi-directionally and in real time. A person added, moved, or offboarded in Greenhouse creates or updates the matching user in Customer.io within seconds, with field-level mapping and conflict resolution in place of spreadsheets and one-off account changes. Where Customer.io captures details of its own, such as a corrected contact or a login identity, those can flow back to Greenhouse in whichever direction you configure.

Because the sync is field-level, each system keeps its own extras; only the shared facts, who a person is, which team they belong to, and whether their access should be on, are held in agreement.

Common use cases

  • 01 Sync product usage and billing attributes from Postgres onto Customer.io people so lifecycle campaigns trigger on real product behavior.
  • 02 Push CRM segments and lead status into Customer.io so messaging respects sales stage.
  • 03 Export Scorecards and Scheduled Interviews to a data warehouse to analyze interviewer load and interview outcomes.
  • 04 Two-way sync Candidates and Applications with Postgres so recruiting-ops apps read and update stage, status, and custom fields in SQL while recruiters stay in Greenhouse.

Common sync patterns

Offboarding: no standing access after a departure

When someone is marked as leaving in Greenhouse, the matching account in Customer.io is deactivated or flagged, so departures do not leave open access behind.

One employee directory

A person's name, title, contact details, or status corrected in either system updates the other, so both sides stop maintaining separate copies of the same person.

Org and team structure kept current

Department, team, and reporting-line changes from Greenhouse keep the groups, queues, or projects in Customer.io assigned to the right people.

What you can sync between Customer.io and Greenhouse

Representative objects on each side — any object or custom field can map to any target. Schemas are auto-detected; types are converted between the two systems.

Customer.io objects Greenhouse objects How this pairing syncs
Campaigns Automated workflows whose membership and metrics can be read via the App API. Jobs Requisitions with openings, hiring team, departments, and offices; created and patched via Harvest, read out for funnel and time-to-fill reporting. Campaigns is specific to Customer.io and Jobs to Greenhouse — each maps to any object or custom field on the other side.
Broadcasts One-off sends to segments or audiences, triggerable via API. Offers Offer records tied to an Application with status and custom offer fields; readable and patchable, commonly synced to HRIS on hire. Broadcasts is specific to Customer.io and Offers to Greenhouse — each maps to any object or custom field on the other side.
Deliveries / Messages Per-recipient message records whose lifecycle events flow out through reporting webhooks. Scorecards Interviewer feedback and ratings tied to interviews; read-only in Harvest, exported to a warehouse for interview analytics. Deliveries / Messages is specific to Customer.io and Scorecards to Greenhouse — each maps to any object or custom field on the other side.
Newsletters Recurring email sends with performance metrics available for reporting syncs. Scheduled Interviews Interview events with interviewers, times, and rooms; full create/update/delete support for calendar and reporting syncs. Newsletters is specific to Customer.io and Scheduled Interviews to Greenhouse — each maps to any object or custom field on the other side.
People Profiles with attributes, matched on identifiers like id or email; the main write target of data syncs. Users Greenhouse users (recruiters, hiring managers); read and written, and referenced by the On-Behalf-Of header on every write. People is specific to Customer.io and Users to Greenhouse — each maps to any object or custom field on the other side.
Objects Non-person entities such as accounts or companies, related to people for account-level messaging. Departments and Offices Org structure attached to Jobs; read and written to keep reporting hierarchies aligned with an HRIS or warehouse. Objects is specific to Customer.io and Departments and Offices to Greenhouse — each maps to any object or custom field on the other side.

How changes propagate between Customer.io and Greenhouse

Each direction of the sync is driven by what the source system can signal and what the destination accepts — detection, delivery, and expected latency below.

Customer.io Greenhouse Sub-second propagation

DetectionCustomer.io notifies Stacksync of record changes through webhook events. Reporting webhooks push message and delivery events.

DeliveryEach detected change is written to Greenhouse through its API, with automatic retries and rate-limit backoff.

Greenhouse Customer.io Sub-second propagation

DetectionGreenhouse notifies Stacksync of record changes through webhook events. HMAC-SHA256 signed webhooks for candidate, application, job, and interview events, plus polling list endpoints with created_after / updated_after /.

DeliveryEach detected change is written to Customer.io through its API, with automatic retries and rate-limit backoff.

Rate-limit considerations

  • Customer.io: Subject to per-API rate limits documented by Customer.io.
  • Greenhouse: Harvest enforces a per-integration limit over a rolling 10-second window (X-RateLimit-Limit, commonly 50 requests / 10s for approved integrations); responses carry X-RateLimit-Remaining and, on a 429, X-RateLimit-Reset and Retry-After.
What ships with Customer.io ⇄ Greenhouse

Connect Customer.io and Greenhouse for flexible, real-time data sync.

Real-time sync, workflow automation, event queues, EDI, and monitoring, for every Customer.io–Greenhouse connection.

Real-time

Two-way sync

Changes in Customer.io or Greenhouse instantly reflect in both systems. No stale data, no manual imports.

No-code + pro-code

Workflow automation

Trigger automated workflows whenever Customer.io or Greenhouse data changes, update records, fire webhooks, or kick off sequences without brittle API scripts.

At scale

Event queues

Handle millions of events per minute without losing a single Customer.io or Greenhouse record.

Observability

Monitoring

Track your Customer.io ⇄ Greenhouse sync health, view errors, and replay failed events in one click.

Trading partners

EDI

Transform legacy EDI complexity into simple database interactions between Customer.io and Greenhouse.

How the Customer.io and Greenhouse connectors work

Customer.io

Integration surface
REST APIs split by purpose: Track API for data ingestion, App API for campaigns, people lookups, and messages
Authentication
Basic auth with site ID and API key for the Track API; bearer token for the App API
Change detection
Reporting webhooks push message and delivery events; person attribute changes are not streamed and require source-side detection
Capabilities
read · write · webhooks
Rate limits
Subject to per-API rate limits documented by Customer.io

Greenhouse

Integration surface
Harvest REST API (plus read-only Job Board API and the Ingestion API for bulk candidate import)
Authentication
HTTP Basic Auth with a Harvest API key (key as username, blank password, colon appended then Base64-encoded); write calls require an On-Behalf-Of header naming the Greenhouse user
Change detection
HMAC-SHA256 signed webhooks for candidate, application, job, and interview events, plus polling list endpoints with created_after / updated_after / last_activity_after filters
Capabilities
read · write · webhooks
Rate limits
Harvest enforces a per-integration limit over a rolling 10-second window (X-RateLimit-Limit, commonly 50 requests / 10s for approved integrations); responses carry X-RateLimit-Remaining and, on a 429, X-RateLimit-Reset and Retry-After.
Greenhouse setup guide
How it works

How to connect Customer.io to Greenhouse — three steps, no code

Configure and sync within minutes, no code. Whether you sync 50k or 100M+ records, Stacksync handles the queues, infra, and plumbing. Integrations are non-invasive and need zero setup on your systems.

  1. 01

    Connect your apps

    Authenticate Customer.io and Greenhouse with each platform's native method — OAuth, API keys, or service accounts — plus secure options like SSH tunneling, IP whitelisting, and VPC peering.

    • OAuth 2.0
    • SSH tunnel
    • VPC peering
    Customer.io connected
    Greenhouse connected
    OAuth 2.0
    SSH tunnel
    SSL certificate
    VPC peering
  2. 02

    Choose tables

    Pick the Customer.io and Greenhouse objects to sync — Stacksync auto-detects both schemas, including custom fields where the platform exposes them. Sync to existing tables, or let Stacksync create new ones with ideal data types.

    • Standard objects
    • Custom objects
    • Auto-schema
    objects · Customer.io ⇄ Greenhouse
    Customers 12,480
    Sales Orders 8,213
    Invoices 5,902
    Items 1,344
  3. 03

    Map fields

    Fields map automatically even when names and types differ. Stacksync handles transformation and type casting for you, zero configuration required.

    • Auto-map
    • Type casting
    • Transforms
    Customer.io Greenhouse
    Company company_name text
    Email email text
    Amount amount numeric
    Created created_at timestamp
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FAQ

Customer.io and Greenhouse integration FAQ

SECURITY

Security teams trust Stacksync

As a data company, we understand the importance of keeping your data secure. Stacksync is built with security best practices to keep your data safe at every layer, and is DPF-certified for US, EU, UK and CH data transfers.

Learn more about security
SOC 2 Type II
ISO 27001
HIPAA BAA
GDPR
CCPA
DPF US-EU-UK-CH
→ SECURITY WITH BENEFITS

SSO & SCIM

Let your users access Stacksync from your centralized user management systems. Works with Okta, Azure, Google SSO and more.

Alerts

Immediately get alerted about record syncing issues over email, Slack, PagerDuty and WhatsApp. Resolve issues from a centralized dashboard with retry and revert options.

Secure connection options

Securely connects to your systems with:

OAuth 2 SSH Tunnelling SSL certificates IP Whitelisting VPN gateway VPC peering and more

Related integrations

Every pair below is a real-time, two-way sync. Search all 417 integrations available for Customer.io and Greenhouse.

Popular · 6 of 417
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