Checkout Performance

Deducto sits in the critical path of your checkout – your storefront calls Verify whenever the cart changes to price it, and Record when the order is placed. That response time is added between a customer changing their cart and seeing their updated total, so it's worth knowing what to expect.

What to expect

Accessed from a region geographically close to your account, Deducto typically responds in under 300ms on average. For most storefronts that's fast enough for promotion evaluation to feel instant as part of a normal cart update or order placement.

Response time isn't a single fixed number, though. It varies with the factors below, so use the figure above as a baseline rather than a guarantee.

What affects speed

Geographic proximity is by far the largest factor. The closer the customer (or, for custom storefronts, the backend making the call) is to your account's region, the lower the network latency and the faster the round trip. Requests that cross continents take noticeably longer than those served nearby.

The remaining factors are worth considering, but in normal operation their effect is small – you'll typically only notice them in unusual cases:

• Number of active promotions – Deducto only evaluates active promotions within their scheduled dates. The more that are active at once, the more there is to consider per cart. Expired promotions don't add cost.
• Promotion complexity – more conditions, overlapping item groups, and lots of item groups all add evaluation time. Simpler promotions are quicker.
• Cart size – measured by unique line items, not total quantity. Each distinct product gives Deducto more to match against your active promotions.

Keeping checkout fast

Most of these factors are within your control: keep promotions active only when needed, favour simpler structures where you can, and be mindful of where your account's region sits relative to your customers. For guidance on keeping the number of active promotions in check, see Managing Usage.

If response times are noticeably higher than you'd expect for your setup, follow Reporting Issues and include timestamps and, where possible, a HAR file.