Hair extension studio bookkeeping

The app was built for Dubai Hair Extensions, a hair extension studio in Dubai. Finances used to be kept in Excel, and the co-owner disliked the formulas: she is a stylist, and her time goes to clients. Now bookkeeping is done from the phone between clients, in Russian and without formulas.

The ready-made accounting service cost about 100 AED a month, or 1,200 AED a year, and worked only in English. The studio needed accounting in Russian, clear to the stylist without formulas. The custom app replaced both the paid service and Excel, and runs without a monthly subscription.

It took one day from the brief to a working version. After launch, improvements were made on the live app, and every change appeared on the technician's phone the same day. The studio started keeping records right away and received improvements as it worked, without reinstalling the app.

The studio receives money in dirhams, rubles and dollars. The exchange rate loads automatically once a day from open.er-api.com, with no manual entry. Each transaction is calculated at the rate of its date. The AED, RUB, USD switch on the main screen recalculates the whole screen in the chosen currency.

The stylist taps «Income», enters the amount, picks «Extensions» and specifies which hair and how much keratin went into the job. The entry screen has four large buttons, and below them the hair color and length, grams, and keratin color and grams. The app calculates the rest itself, and the month's profit updates immediately.

Hair is tracked in grams for each "color + length" pair, because it is purchased in different colors and lengths at different prices. Keratin is tracked by its own colors, and consumables and cosmetics by pieces. When a job is entered, the grams are automatically deducted from stock of the right color and length.

It's the amount currently sitting on the shelf in hair and keratin. For an extension studio owner, it's important to see how much money is tied up in materials before they go into work. The figure appears on the main screen next to the month's net profit, income and expenses.

If a purchase is written off entirely as an expense, the month of a big batch looks unprofitable, even though the hair has not even started to be used. In the app, only the cost of the hair and keratin actually used in work goes into profit. The rest of the purchase sits in stock and shows as frozen money.

The app has 47 automated tests that check money and stock calculations and login. The server is built on Node.js and Fastify. Checking the calculations matters because a single operation in this accounting instantly changes the month's profit, converts currency, and writes off grams of hair and keratin from stock.

The SQLite database is copied every day, and each day's copy is kept for 30 days. In 25 days, 25 of 25 copies were made. Each studio uses its own separate database. After a server restart the application comes back up on its own via systemd, with no manual start.

Login uses a PIN code. After 5 wrong attempts, login is blocked for 15 minutes, which makes guessing the code hard. The app is closed to search engines, and the connection is encrypted with nginx and Let's Encrypt. This keeps the studio's financial data hidden from outsiders.

The app weighs about 40 KB, and in SEO7's measurement the first page opened in 0.14 seconds. That suits a stylist who enters transactions between clients. The app is added to the iPhone Home Screen without the App Store and opens like a regular app.

Everyday changes are made right in the app. You can add a new hair or keratin color, create a new supply item, run a warehouse stocktake and see profit in any of three currencies: AED, RUB or USD. You don't need a studio developer for these tasks.

Just describe how your studio keeps its records now. Within 2 days SEO7 will show what the app would look like for your services, materials and currencies. A reply comes within an hour, the estimate is ready in 48 hours, and once agreed the price will not rise.