What This Is Really About
Not plumbing. Agreeing which system is right.
Connecting two systems is a technical job. Deciding what happens when your CRM says a customer’s address is one thing and your accounting system says another is a business decision, and it is the part that stalls integration projects.
Every integration of any size runs into it, usually about a week in, and the projects that go well are the ones where somebody with authority answers it rather than asking the developers to guess.
The Questions That Have To Be Answered By You
- Which system owns each piece of information? For every field that exists in more than one place. Customer name, address, phone, status, price.
- What happens when both change? Last write wins is simple and occasionally wrong in expensive ways.
- What is the definition of a customer? Two systems rarely agree, and the mismatch is where duplicates come from.
- What happens to records that do not match? There will be some. They need a home rather than a silent failure.
Nobody enjoys this conversation and it is the whole project. A supplier who does not force it early is storing up a problem for you.
Point To Point Or Through A Hub
Point to point connects each pair directly. Fine for two or three systems. At five it becomes a web nobody can reason about, and changing one thing means checking six connections.
Through a hub routes everything via one place that holds the canonical record. More work initially, dramatically less afterwards, and it gives you somewhere to answer the ownership question once rather than repeatedly.
The switch is worth making earlier than most businesses do, because the point-to-point web is easy to grow into and painful to unpick.
What Moves The Price
Number of systems, and more importantly the number of pairs that need to agree.
Whether any of them lack a usable API. One system without one can define the whole approach, sometimes forcing scheduled file exchange instead of live integration.
How much historical data has to be reconciled before the ongoing sync can start. Frequently the largest single piece of work and routinely underestimated.
How much the definitions differ. Two systems with the same idea of a customer integrate quickly. Two that disagree need a mapping layer and a set of business rules.
Where These Projects Go Wrong
Starting with the technology. The tooling is rarely the constraint. The unanswered ownership questions are.
No reconciliation. Systems drift. Without something comparing them on a schedule, they diverge quietly and you find out from a customer or an accountant months later.
Silent failures. An integration that stops looks identical to one with nothing to do.
Migrating the mess. Integrating without cleaning duplicates first spreads them everywhere, and afterwards it is much harder to tell which copy was the original.
Questions To Ask Whoever Quotes For This
- Which system will own each field? If they have not asked you, they have not scoped it.
- What happens when they disagree? There should be a described rule per field.
- How will we know it has stopped working?
- What reconciliation runs, and how often?
- What happens to records that cannot be matched?
- Have you looked at our actual data, or only the documentation?
A Brief You Can Send Anyone
Systems involved: [names, versions, and who administers each]
What is entered twice today: [the specific duplication]
Which system we trust most for what: [your instinct is useful here]
Volume: [records, and how often they change]
What must be immediate: [and what can wait until overnight]
Known data problems: [duplicates, inconsistent formats, gaps]
Who can decide the rules: [one name, with authority]
How We Work
The first deliverable is usually a written field-ownership map rather than any code, because everything else depends on it and it is cheap to change on paper.
Then a hub where the volume justifies it, live where the APIs allow and scheduled where they do not, with reconciliation comparing both sides so drift is found by us. Every exchange logged.
For connecting a specific pair of systems, API integrations is the narrower version of this. Get in touch with the list of what your team types twice.
