API integrations

Flat 18 connects products to the services they depend on: payments, CRMs, analytics, data platforms, automation tools and internal systems. We keep integrations practical, secure and documented.

What matters

• Senior engineers with broad integration experience
• Clear data contracts and error handling
• Security, auth and rate limits considered early
• Useful documentation for future changes

What we build

Integration work often sits inside a wider MVP or product build. We can also take it on as a focused technical project.

• Third-party API integrations
• Private APIs for products and internal tools
• Payment, email, analytics and CRM connections
• Webhooks, background jobs and data syncs
• Testing, monitoring and handover notes

Integration process

1. Map: data, permissions and failure cases.
2. Design: choose the simplest reliable flow.
3. Build: implement, test and document.
4. Release: monitor the integration and hand over clearly.

Technologies We Work With

• REST APIs
• GraphQL
• WebSockets and webhooks
• OAuth, JWT and signed requests
• OpenAPI documentation

Need systems connected?

Tell us what needs to talk to what, and what must not break.