The connections nobody else wants to build
Two systems, one missing bridge. The work is in the unglamorous parts — authentication, rate limits, pagination, retries, idempotency.
Inside the build
Anyone can call an endpoint. The difference shows at 2am on the busiest day of the month, when a vendor rate-limits you mid-sync and the retry logic decides whether you wake up to a clean queue or fourteen thousand duplicates.
- Data stays in sync — One source of truth, propagated reliably in whichever direction the business needs.
- Built for failure — Retries with backoff, idempotency keys and replayable queues as standard.
- Documented contracts — Field mappings and behaviours written down rather than inferred from the code.
- Secure by default — Secrets in a vault, signed webhooks, least-privilege scopes and rotation.
What is included
Everything here is delivered, documented and handed over. Nothing is left depending on my availability.
Any protocol
REST, GraphQL, SOAP, webhooks and the occasional flat-file drop that still runs the business.
Authentication
OAuth2, JWT, HMAC signing and API-key handling with proper rotation.
Middleware services
Small, testable Node.js or Python services that own the mapping and the rules.
Rate and volume strategy
Queueing, batching and backoff that stay inside the vendor's ceiling.
Validation layer
Transformation and schema validation before anything is written downstream.
Monitoring and replay
Alerting on drift plus tooling to replay a failed batch without duplicating it.
What companies describe, and what gets built
Left is the symptom as it is usually reported. Right is the actual fix.
The vendor has no native connector for your CRM.
A middleware service that speaks both sides, owns the field mapping and is documented as a contract.
Sync breaks quietly and duplicates pile up.
Idempotency keys on every write and a reconciliation job that reports drift before anyone notices it.
Their API rate-limits you at month end.
Queueing with exponential backoff and batched writes sized to the published limit.
The path one item takes
Every stage is logged, and every failure has a defined destination.
Built for the night it goes wrong
Integrations are judged on their worst hour, not their happy path.
- Idempotency keys on every write, so a retry can never duplicate a record
- Exponential backoff with jitter, plus a circuit breaker after a failure threshold
- Cursor-based pagination where offered, and stable sorting where it is not
- Dead-letter queue holding failed payloads for replay once the cause is fixed
- Nightly reconciliation comparing both sides and reporting any drift
- Secrets in a vault, signed webhooks, and scoped credentials rotated on schedule
Where this lands hardest
Technologies used
Measured before and after, by the client
Placeholder figures. Replace with your own verified numbers before launch.
Frequently asked
About API Integrations specifically.
Common, and not a blocker. I work from live traffic inspection and produce a written contract as part of the project — which is often the first accurate documentation that integration has ever had.
You do. Repository, documentation and deployment instructions are handed over at the end of the build.
Yes, either on a support retainer or through an included window after launch. Vendor APIs change, so something eventually needs attention.
Against sandbox environments where they exist, and with recorded fixtures where they do not, including the failure cases.
Related services
Rarely bought alone.
Tell me what is taking too long
Thirty minutes, no pitch. If automation is the wrong answer for your situation, you will hear that on the call.
Reply within one business day · NDA before any system detail is discussed