Same-day payouts for Kedaiwira

Sellers used to wait three days for their money. Now they are paid before 6 pm on the day the order is delivered. Kedaiwira: online marketplace for 26,000 small Malaysian sellers.

T+0

seller payouts, from T+3

Client: Kedaiwira
Role: Product engineer, payments
Duration: 3 months
Shipped: 2023.10, v1.2
Stack: Python, Django, PostgreSQL, Celery

Problem

For a small seller, three days of float is the difference between restocking this week or next. Kedaiwira paid out in one nightly batch, three working days after delivery, and 1.9% of payouts bounced back because of closed accounts or name mismatches.

Each bounce was fixed by email, and the seller was not paid until someone in operations noticed.

Constraints

3 that shaped the design

Instant transfer rails have per-transaction fees, so batching still matters for very small amounts.
Bank account names must be verified before the first payout, without asking sellers for documents again.
Refunds and disputes can arrive after a payout has gone out.

Architecture

scroll sideways to see all of it

Delivered orders accrue into a seller balance. A cutoff job pays out what is safe to pay, and holds a small reserve.

boxes are servicesdouble top rule is a storedashed is async or advisorygreen is what this project built

Code

excerpt, lightly trimmed

The payout run is one query. Anything it does not select simply waits for the next run.

payouts/select.sqlsql

1-- Sellers eligible for this run, amounts in sen2SELECT s.id, b.available_sen - b.reserve_sen AS payable_sen3FROM sellers s4JOIN seller_balances b ON b.seller_id = s.id5WHERE s.bank_name_verified6  AND NOT s.payouts_paused7  AND b.available_sen - b.reserve_sen >= 1000   -- RM 10 minimum8FOR UPDATE OF b SKIP LOCKED;

Result

measured, not estimated

payout daywas ~~T+3~~: T+0
bounced payoutswas ~~1.9%~~: 0.2%
paid out on the launch week: RM 4.1m
seller retention after 6 months: +8%

Operations retired the payout spreadsheet the following month. The two daily runs are still the only scheduled jobs that touch money.