One missing database write, traced across two providers and fixed for good
Deal Dunk’s paid orders were piling up unshipped, and nobody could say why. We traced it to a single field that was never written, proved every stalled order had been paid, and drained the backlog without a single wrong write.
- 2,000+ stalled orders released
- 0 failed writes
- 2 Shopify Functions shipped
- Client
- Deal Dunk
- Industry
- Subscription e-commerce
- Services
- Systems integration, Shopify apps
- Engagement
- April 2026 – ongoing
A membership store with a delayed hand-off
Deal Dunk sells a membership: a low-cost signup unlocks a free item, which ships once the first recurring charge clears. Shopify owns the order; a separate billing platform owns the subscription. Our app sits between them and tracks each order through its lifecycle.
- 01
Signup
The customer pays a small signup fee at Shopify checkout and picks a free item.
- 02
Subscription created
The billing platform starts a membership subscription for that customer.
- 03
Item held
The free item waits until the first full membership renewal clears.
- 04
Released to ship
A paid renewal releases the held order to fulfillment.
Members-only pricing on Shopify
Every price on the store is a member price. Behind it, our app tracks each order from signup to shipment, and our Shopify Functions apply the membership rules at checkout.
A review queue growing by 200 a day
Orders tagged for manual review went from 92 to over 2,600 in about ten days. Each one was a customer who had paid and wasn’t being shipped. The store’s volume had just tripled, so the obvious explanations were load, a bad batch job, or our own cleanup tooling flagging orders by mistake.
Before changing anything, we built read-only measurements and grouped every review decision by its reason. The cleanup tooling accounted for 36 rows in 30 days. One reason accounted for 81% of everything.
Not written unreliably. Never written at all.
The release logic correctly required an order and a renewal to share the same subscription ID. No live code path ever stored that ID on the order.
The link was never written
The order's subscription reference was read by the release logic but never assigned by any live code path. With it empty, a paid renewal could never find its order.
Paid orders flagged as suspicious
Stuck orders were then flagged for manual review whenever the customer bought again. 81% of the review queue came from this one cause.
Every one was actually paid
We checked all 2,026 orders in that cohort against the billing provider. All 2,026 had a successful renewal: the status was stale, not the customer.
A second, separate defect
Some renewals failed before any card was ever charged. A control group proved why: those subscriptions had been created with no payment method attached.
Fix the write, then repair the past safely
Correcting the code stopped new orders from stalling. The thousands already stuck needed a backfill against live production data, where one careless run could refund, cancel or ship the wrong order.
The billing platform stamps each Shopify order with its subscription, so the correct link already existed upstream. We read it back for every held order, compared it with what we had archived, and wrote it only where both agreed.
Every step ran in the same order: measure read-only, report the number, get the owner’s go-ahead on anything involving money, then run the guarded executor. Refunds and cancellations stayed the client’s decision, never inferred.
Once the backlog was clear, the same close-out jobs were moved onto a schedule, so failed renewals and cancellations are now cleared daily without anyone at a terminal.
Kill switch
Every write path ships disarmed and is switched on only for a run.
Exact confirmation
A run needs an explicit list of order IDs and a typed confirmation string.
Per-call caps
Batches of 20 to 100, so a mistake touches a handful of orders, not thousands.
Live re-check
Each order is re-read from Shopify and billing right before it's written.
Read-back, not guesswork
A timeout isn't treated as a failure: we read the order back before reporting or retrying.
Whole-range verify
After each run, the full population is re-scanned to count what's left, not what was touched.
One place to see where every order stands
The admin app we built and run for Deal Dunk: every order, charge and hold in one view, so the operations team can see what's ready to ship and why anything isn't. Customer details are blurred here.
Verified against live data, not a run log
Each figure comes from a fresh scan of Shopify and the billing platform after the run, so anything a run silently skipped would still show up.
Orders relinked to their subscription, 0 mismatches
Held orders missing a subscription link
Stale orders reconciled with Shopify, 0 failed
Backlog orders closed out under guarded runs
Native Shopify Functions for checkout
Alongside the integration work, we built Deal Dunk's Shopify app with two Functions that run inside Shopify's own checkout, with no scripts or third-party redirects.
Membership discounts
A discount Function that prices cart lines and delivery options for members, running natively inside Shopify checkout.
Checkout validation
A cart and checkout validation Function enforcing the promo rules: one free item type per cart, membership required for paid items, and quantity limits on helper products.
Need something similar? See API & systems integration and Shopify development and custom apps.
Orders or payments going missing between systems?
Tell us which tools are involved and what you're seeing. We'll trace it, tell you what we find, and quote a fixed price for the fix.
Fix a broken integration
Describe the systems involved and what's going wrong. We'll reply with questions and next steps.
- Read-only diagnosis before any change
- Guarded fixes on live data
- Built and supported from Cebu