API & systems integration

Accounting, logistics, POS, CRM, payment providers, WhatsApp. Integration work is unglamorous and high value: done right, an entire manual job disappears. My API integration services connect the systems you already use so data moves between them reliably, without someone re-typing it.

The problem

Most businesses run on several systems that were never designed to work together. Orders come in on the website and get typed into accounting. Leads arrive by WhatsApp and get copied into the CRM. Stock is updated in one place and forgotten in another. Every manual step is slow, and every one is a chance for a mistake that someone has to find later.

What API integration services include

First I study both sides: what each system’s API can and cannot do, how it authenticates, its limits and how it reports errors. Then I design the flow: which system is the source of truth for each piece of data, what triggers a sync, and how fields map from one side to the other.

The build is where reliability comes in. Syncs run through queues, so if one system is down, nothing is lost and the job retries later. Each operation is idempotent, meaning a retry cannot create a duplicate invoice or a second order. Rate limits are respected, and anything that fails repeatedly goes to a dead-letter queue where it can be inspected and replayed. Every sync is logged, so when someone asks why a record looks wrong, there is an answer.

I finish with documentation: what connects to what, where the credentials live and how to handle the common failures, so the next developer is not guessing.

How a project runs

Discovery starts with the manual job you want to remove. I watch how it is done today and list the systems and fields involved. I then build against test or sandbox accounts where the providers offer them, and run the integration alongside the manual process for a short period so results can be compared. Launch switches the manual step off. After launch I monitor the logs and handle API changes from the providers as they come.

Cost and timeline

Integration projects usually take 2–8 weeks, depending on the number of systems and the quality of their APIs. I give you a written estimate after discovery.

FAQ

What if one of the systems has no API?

There are often other routes, such as scheduled file exports, email parsing or a database connection. I will tell you which is reliable enough to depend on.

Can you connect WhatsApp?

Yes, through the WhatsApp Business Platform, for notifications and for bringing conversations into your CRM.

Who maintains it when a provider changes their API?

I can, through a maintenance retainer, or your own developers using the documentation I leave.