For the responsive and bright front end, we used Kotlin for the Android version and Swift5 for the iOS app. For the Backend, Golang and PostgreSQL were chosen to develop the core logic of the application.

The client registers in the app and adds the address where the service is expected. When logging in next time it's possible to just opt for "repeat the cleaning" without having to choose all the cleaning options anew or select the "new clean-up" and pick the cleaning services needed. Then, the user proceeds to the calendar screen with available cleaners and days/hours.
To ensure real-time updates of available cleaning times web socket technology was added. So when two users almost simultaneously book the service the risk of assigning the same cleaner for both of them for the chosen timeslot is eliminated.
The next step is to choose the method of payment and confirm the order.
To double-confirm the service the app sends notifications to clients and cleaners. That is provided by Firebase notifications.

For admins of the company, we implemented a management website in JavaScript, Typescript, and Mobx. On this website, they can check the number of orders and clients' feedback per cleaner, and edit cleaners' profiles and working hours. Also see the lists of constant customers, correct loyalty programs and discounts, and address clients' comments.