Integration is one of those words that sounds finished the moment it is said. “The POS integrates with your accounting package.” Does it? In real time, or once a night? Both directions, or one? What happens to a sale when the connection is down for ten minutes during a rush? The gap between “there is an API” and “the data is always right” is where most operators get hurt.
Real-time where it matters, batched where it does not
Not everything needs to be instant, but the things customers feel do. Stock levels behind click-and-collect, loyalty balances and payment status should be current to the second. End-of-day accounting totals can batch. Good integration is deliberate about which is which, rather than treating everything the same.
It survives failure without losing data
Networks drop and services go down. The test of an integration is not whether it works on a good day but what it does on a bad one. It should queue what it cannot send, retry safely without creating duplicates, and reconcile automatically when the other side comes back. A sale should never vanish because a webhook failed.
One source of truth per fact
When two systems both think they own the customer record or the stock count, they will disagree, and someone will spend their week reconciling. Decide which system owns each piece of data and let the others read from it. This single decision prevents more integration pain than any amount of clever syncing.
Observable, so you find problems before customers do
A quiet integration is not the same as a healthy one. You want logging and alerts that tell you a sync is failing now, not a customer telling you next week. The best integrations make their own health visible.
Built on supported interfaces
Screen-scraping or undocumented endpoints feel cheap until the other side changes something and your integration breaks silently. Wherever possible, build on official, supported APIs. It costs a little more up front and saves far more later. This is the difference we design for in our integration work.
If your systems do not talk to each other properly, tell us what you are running and we will map a way to join them up.
Frequently asked questions
- What does it mean for two systems to be "integrated"?
- Genuine integration means the systems share data reliably and automatically, in the right direction and at the right time, and recover cleanly when something fails. A one-off export or a nightly file is a much weaker form of integration than a real-time, two-way connection that never drops a transaction.
- Why do POS integrations fail?
- Most failures come from building on unsupported or undocumented interfaces, having no plan for connection failures (so data is lost or duplicated), or letting two systems both own the same data so they drift out of sync. Reliable integrations use supported APIs, queue and retry safely, and give each fact a single source of truth.
- Should POS data sync in real time or in batches?
- It depends on the data. Anything a customer feels - stock availability, loyalty balances, payment status - should be real time. Back-office totals like end-of-day accounting can safely run in batches. Good integration design decides this case by case.