Every enterprise has a collection of systems that were not designed to talk to each other — an ERP from 2008, a CRM that was customised beyond recognition, a payment gateway with a 200-page API specification, and three different logistics providers with three different data formats. Connecting these systems reliably is genuinely difficult work. Key Brains specialises in integrations that handle the real world — timeouts, rate limits, partial failures, duplicate events, and the inevitable breaking change on the other side of the API.
Before we write a line of integration code, we document the integration architecture — the data flow, the transformation rules, the error handling strategy, the retry logic, the idempotency approach, and the monitoring plan. Integration failures are often silent. A batch job that quietly stops processing because a third-party API changed a field name is worse than a crash, because it takes longer to notice.
We have integrated with SAP, Microsoft Dynamics, Salesforce, HubSpot, Zoho, and a number of proprietary ERP systems built for specific industries. We understand the data models, the authentication mechanisms, the rate limits, and the undocumented behaviours. We build integration layers that are decoupled from both systems — so that when one of them changes, the blast radius is contained.
Stripe, Razorpay, PayPal, Braintree, and regional payment providers — we have implemented them all. More importantly, we have implemented them correctly — webhook verification, idempotency keys, refund handling, dispute management, and the correct handling of asynchronous payment confirmation, which is the part that most implementations get wrong.
We have built integrations with FedEx, DHL, UPS, Shiprocket, Delhivery, and a number of other logistics providers. Real-time rate calculation, label generation, tracking event processing, and the handling of returned shipments. These integrations require defensive programming — logistics APIs are inconsistent, their test environments do not match production, and their webhooks are frequently late or missing.
For high-volume or reliability-critical integrations, we build middleware layers using RabbitMQ, Apache Kafka, or AWS SQS. Message queuing decouples the systems, provides a buffer for rate limiting, enables replay in case of downstream failures, and gives you a complete audit log of every event that passed through the integration.
When we build APIs for third parties to consume, we design them to be stable, versioned, and well-documented. OpenAPI specifications, Postman collections, sandbox environments, and API changelogs. We design for the developer experience of the person on the other end of the integration.
Free 30-minute architecture call — no obligation, no sales pitch.