Connecting a CRM to an accounting system sounds like a single project: turn on a sync, done. In practice it's five separate decisions, made or skipped, and almost every integration that breaks later broke because one of these was never actually decided — it just defaulted to whatever the first person to touch it assumed.
1. Which system is the system of record
If a customer's name or address can be edited in either system, there has to be a rule for which one wins when they disagree. "We'll figure it out when it happens" is how the same customer ends up with two different addresses and nobody knows which is current.
2. Which direction data flows
One-way (CRM → accounting) is simpler and safer. Two-way is more useful, but only works once decision #1 is already settled — otherwise a two-way sync just recreates the same conflict automatically, on a schedule, instead of only when someone happens to notice it.
3. What happens to duplicates
Matching records across two systems needs a rule — email, phone number, an internal ID — decided in advance, not discovered the first time the same customer shows up twice because their name was typed slightly differently in each system.
4. What happens when the sync fails
Syncs fail. An API times out, a field doesn't match a required format, a record is missing something the other system needs. The real question is whether that failure is visible — an alert, a queue someone checks — or silent, where an invoice quietly never posts and nobody notices until a bank reconciliation catches it weeks later.
5. Who checks it's still working
Someone needs to own a recurring, scheduled check — even five minutes a month — instead of "the sync" being nobody's specific job until it's visibly broken and a client is asking why their invoice never arrived.
None of these five decisions require new software. They need to be made explicitly, in writing, before the connection goes live. Mavryn's CRM integration build starts by settling all five up front, so the connection holds up instead of quietly drifting.