Flashlight Cleanstar
Building a digital workflow for a motorcycle wash, including a public self-service tablet that is not given access to set prices.
- Client
- Flashlight Cleanstar — motorcycle wash & detailing, Malang
- Industry
- Automotive services
- Our role
- Product definition, system architecture, and development — with the team
- Duration
- About 5 months (February – July 2026)
- Year
- 2026
Scope at a glance
4
connected apps: kiosk, POS, public site, server
5
screens with distinct jobs, from customer tablet to queue TV
2
branches
0
prices the customer device is able to send
The problem
Nothing was digitised. Transactions, bookkeeping, and order records were all handled by hand, across two branches.
The queue and order log did not have a consistent format. Customers were still informed of their turn by calling out directly.
Helmet, shoe, and apparel cleaning takes days, and customers do not wait on site. Without a trackable record, dropped-off items easily lose their trail — and customers could only phone in to ask whether their things were ready.
The cash drawer often failed to reconcile at closing, with no record to trace the difference against.
The owner did not yet have a view of net profit by service. Without recorded cost prices, revenue alone was not enough to understand margin.
Constraints
- An unauthenticated tablet stands in a public room. Anyone can touch it, including someone intending to change a price.
- The shop cannot stop serving customers just because the internet drops.
- The receipt printer the shop already owned uses a connection browsers do not support, so the path had to run over a USB cable.
- No payment gateway. Cash and card terminal only, recorded manually by the cashier.
Approach
The customer device is not given access to set prices
An order request from the tablet carries only the identity of the customer, vehicle, service, and additional items. The server determines every amount, while the customer device sends no price field. This separation helps reduce the risk of price changes from the public kiosk.
Queue numbers are issued by the database, not the application
Reading the highest number and adding one can produce duplicates when the kiosk and POS save an order at the same time. Numbering was therefore moved into the database as a single operation, with a uniqueness rule per date.
Every amount is stored as a whole rupiah
Amounts are stored as whole rupiah values, and the database rejects negatives. This helps prevent rounding errors. When a discount is divided across a combined payment, the largest-remainder method keeps the parts aligned with the total.
Cost price is frozen onto every transaction
A service's cost price is copied onto the transaction at the moment it is created, rather than read back from the catalogue when a report is opened. Otherwise raising a price today would silently rewrite last month's profit report. Category names and overnight fees are treated the same way.
The kiosk has to work without internet
The tablet keeps the catalogue on the device and holds unsent orders in a local queue. Once the connection returns, orders are retried automatically while customers see an offline indicator.
Customers check for themselves via a QR code on the receipt
The receipt carries a QR code to a tracking page that needs no login. Customers can check the status of dropped-off items without always phoning the shop, which may reduce status enquiries handled by staff.
Screens
Observed outcomes
The whole shop flow now has a digital form: customers register themselves at the tablet, join a numbered queue, appear on the waiting-room TV, are processed at the POS, and pay with a printed receipt.
Multi-day drop-offs have their own docket number, an estimated ready date, and a tracking link the customer can open at any time.
The closing process now records opening float, cash and card sales, expenses, a physical count by denomination, and any difference with a written reason.
Reports provide profit information alongside revenue, while cost prices are restricted on the server and are not sent to cashiers or ordinary administrators.
An honest note: business impact has not been measured, and this system still lacks adequate automated testing on the interface side. That is open work, not something we are hiding.
Other projects
Darmabox
2026Consolidating work that used to live across several disconnected apps — from costing a custom box to the accounting entry posting itself.
Bersama Jaya Cup
Bersama Jaya Cup
2026Bringing a packaging printing company's records into one system while retaining working habits that remain useful to the team.
Ready when you are / →
Working through a similar need?
Tell us about the situation. Together, we can map the need, possible approaches, and an initial scope.
We usually reply within one business day.