System and API integration: Stop retyping orders between systems.
Connecting the systems a business already pays for – couriers, payments, accounting and suppliers – so that work stops being retyped between them.
Two published case studies
We reply within one working day
What that includesINTEGRATION
Couriers, payments, suppliers
- Courier vouchers, labels and tracking straight from your orders
- Card payments and payment providers connected to your store
- Supplier stock and price lists imported automatically
- Accounting and invoicing kept in step without retyping
- Connections that retry on their own when a service is down
- Our own free, open-source WooCommerce courier plugin
Integration work is rarely difficult and frequently nasty. The interface is documented incorrectly, the errors arrive with a success status code, field names are misspelled in the response, and the rate limit uses a status nobody expects.
We deal with that by putting the third-party client in its own layer with no dependency on the surrounding application, then testing it against recorded responses from the real service. Every behaviour we have been bitten by becomes a test, so it can only bite once.
The result is that a courier, a payment provider or a supplier feed can be exercised in milliseconds on a laptop, and an upgrade to the surrounding system cannot quietly break the connection to it.
01Who it is for
A business where someone retypes the same order, address or invoice from one system into another, or where a connection to a courier or a supplier breaks without anyone noticing until a customer does.
If this is the wrong service for you, we will say so and point you to the right one.
02What you get
- A connection to each service in its own layer, independent of the rest of the system
- A test suite recorded against the real service, covering every failure we have seen from it
- Scheduled synchronisation that retries and backs off instead of giving up quietly
- Payment checkouts and webhooks, courier vouchers and tracking, supplier and price feeds
You can read one of these in full: our ACS Courier plugin for WooCommerce is open source, and its test suite is part of the repository.
03What we need from you
Your own account with each service, with API access switched on; whatever documentation the provider gives you; and a few examples of what goes wrong today, since those become the first tests.
Is this what you need?
Describe the job in a few lines. If this service is the wrong fit, we will say so and point you to the right one.
Get a quoteWe reply within one working day
Proof
Where we have done it
Two case studies, written from the source code and anonymised.
-

Pickup-point delivery at checkout for an electronics store
A Cyprus electronics retailer
Customers choose a courier pickup point at checkout, with delivery prices by area, free delivery over a set amount, and a ready place to connect the courier's own system.
In use at checkoutRead the case -

A point of sale that shares one catalogue with the web store
A Cyprus specialist retailer
Replaced an off-the-shelf point of sale plugin with a terminal built for the business, and rebuilt the storefront so changes can be rehearsed first.
In use · counter and web storeRead the case
How we work
How an engagement runs
Four steps, and we stay after the fourth: what we build, we host and support.
- 01
Discovery
We map how the business actually runs today, including the spreadsheets and the workarounds.
- 02
Build
We build the system in small, shippable pieces you can use before it is finished.
- 03
Integrate
We connect it to the couriers, payment providers and marketplaces you already depend on.
- 04
Host and support
We run it on infrastructure you own or on ours, as agreed, with backups, monitoring and someone to call.
Budget
What it costs
We do not publish fixed prices. When you write, choose a budget band: Under €10k, €10–30k, €30–100k, €100k+ or Not sure yet. Every range is welcome, and within one working day we reply with whether software is the answer and roughly what it would take.
- Under €10k
- €10–30k
- €30–100k
- €100k+
- Not sure yet
Questions
Questions aboutthis service
Something else you want to know? Ask it in your enquiry, or write to us directly.
inquiries@kdvassiliougroup.com01Can you work with the systems we already use?
Usually that is the job. We connect what a business already pays for — couriers, payment providers, accounting and suppliers — so that work stops being retyped between them.
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Start a project
Bring us the problem, not the spec.
We will tell you whether software is the answer, and roughly what it would take.
Tell us what is slow or broken, when you need it, and your budget range.
- Under €10k
- €10–30k
- €30–100k
- €100k+
- Not sure yet
We reply within one working day