The dirty secret of integration quotes is that the flows are cheap and the edges are expensive. Mapping an order to an ERP is a day of work; deciding what happens when the ERP is down for maintenance mid order, when a SKU is renamed between systems, or when a refund lands during a replan is where the real engineering lives. Our quotes price the edges explicitly, which is why they sometimes look higher than a marketplace connector and lower than the total cost of owning one.
Native connectors are the apps and built in integrations that come with each platform. They are the cheapest and fastest option, and they are the right answer when your flows are standard and your volume is moderate. Their limits show at the edges: field mappings you cannot change, sync frequencies you cannot raise, and errors surfaced as a red badge with no detail. When a connector covers your flows and nobody has to babysit it, use it. We say this first in every audit because it is the cheapest honest answer.
An iPaaS (Boomi, Celigo, Zapier at the simple end) buys you managed middleware: prebuilt connectors, visual mapping, monitoring and error queues without writing a synchronization engine. It suits teams who want configuration over code, multiple systems connected quickly, and a vendor contract instead of a codebase. The costs are subscription fees that scale with volume, and a ceiling: the day your logic needs custom rules, retries tuned to your warehouse hours or transformations iPaaS cannot express, you are back to workarounds.
Custom API integration is what we build when the logic is yours. A small service, Cloudflare Workers or Node, that consumes Shopify webhooks, applies your rules, writes to the target system and reports reconciliation. You own it, its limits are yours, and its behaviour is documented in your runbook instead of a vendor's changelog. It costs more than a connector on day one and less than an iPaaS by year two at volume. The audit lays out all three with real numbers for your flows, and we build whichever wins.
Whichever route, the engineering rules are the same. Every flow is idempotent so retries are safe. Every failure lands in a queue with an alert that names the record and the reason, never a silent drop. Reconciliation reports run daily: orders out, confirmations back, mismatches listed. And the sync behaves sensibly at the boundaries: paused during your warehouse count, throttled during flash sales, versioned when the ERP upgrades. Boring, observable plumbing is the entire product.