Crescentek

Integration & Systems Work

Integrations that stay working.

Third-party API connections, system-to-system sync, and workflow automation — built with retry logic, failure alerting, and monitoring from the start. Not just until go-live.

Based in Ireland
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Integration monitor
Live
Orders → Fulfillment
Healthy
Shopify → 3PL System1,204 today
Leads → CRM
Syncing
Website → HubSpot3 queued
Invoices → Accounting
Error
Stripe → Xero2 failed
Inventory → Warehouse
Healthy
ERP → WMSReal-time
3/4 healthy · 1 needs attentionInvestigating Xero sync
Why integrations fail

Five things documentation doesn't warn you about.

Most integrations break not at launch, but weeks or months later — when the edge cases documentation never mentioned finally appear in production.

Third-party APIs change without warning and break integrations silently
Rate limits hit in production but not in testing — under realistic load
Webhook delivery failures go unnoticed if there's no retry and alert system
Data type mismatches between systems cause corruption that surfaces weeks later
Auth token expiry and refresh logic breaks at the worst possible time
What we build

Four integration patterns, done properly.

Each integration type has different failure modes. We've encountered most of them and build accordingly.

Third-party API integrations

Stripe, HubSpot, Salesforce, Xero, Shopify, Twilio — we've connected most of them and handle the edge cases (rate limits, webhooks, error handling, retry logic) that documentation doesn't warn you about.

System-to-system sync

CRM to ERP, website to fulfilment, POS to accounting — bidirectional data flow with conflict resolution, audit trails, and failure alerting built in.

Legacy system bridges

Connecting a modern frontend or new service to a legacy backend that doesn't have a proper API. We build the translation layer that lets old and new systems coexist.

Workflow automation

Zapier and Make handle simple linear flows. When the logic gets complex — conditionals, branching, error recovery, custom transformations — we build the automation properly.

01
Map the data flow

Before writing a line of code, we document every field, transformation, and dependency between systems.

02
Build with failure in mind

Every integration assumes the other system will fail. Retries, dead-letter queues, and alerts are built from the start.

03
Test against real conditions

We test with realistic data volumes, simulated failures, and rate-limit scenarios — not just happy-path unit tests.

04
Monitor and document

Integrations need ongoing attention. We set up monitoring dashboards and document the system so the next developer can maintain it.

Common questions

Integration questions answered.

The questions Irish SMBs ask us most often.

Yes. CRM integrations are one of the most common requests. We handle the full implementation: OAuth setup, field mapping, bidirectional sync logic, webhook handling, and error alerting. We work with HubSpot, Salesforce, Zoho, and others.
Yes. This is a regular rescue scenario. We audit the existing integration code, identify why it's failing (usually missing error handling or retry logic), and either fix it or rebuild it properly. We document what we find and what we changed.
We've handled this before. Options include: screen scraping (fragile but sometimes necessary), FTP/CSV-based data exchange (reliable if the system supports it), direct database integration (requires access and careful handling), or building a middleware layer.
We implement whatever the third-party system requires: OAuth 2.0, API keys, HMAC signatures, JWT — and we handle token refresh, storage, and rotation correctly. We don't hardcode credentials or leave tokens in version control.
Yes. Not all integrations need to be real-time. Scheduled batch sync is often more reliable and easier to debug than event-driven integration. We choose the right approach based on the tolerance for data latency and the volume involved.
At minimum: failure alerting, sync status dashboards, and a dead-letter queue for failed records. For high-stakes integrations (payments, fulfilment), we add detailed audit logging and rate-limit monitoring.

Need two systems to talk to each other reliably?

Tell us what you're connecting. We'll scope the integration and tell you exactly what the edge cases are.

Reply within 1 working day GDPR compliant Based in Ireland