GreenMaster Go

Software for a pest-control company. Technicians fill in each visit on their phone, the customer signs it off on the spot, and the office runs it all from the web. I built most of the backend, the web admin and the phone app.

Role
Software Engineer
Team
Freelance for Madeezi, with one other developer
When
May 2025 – June 2026
Built with
Rails, React, Expo, PostgreSQL
Names and contacts replaced with sample data; other client sites blurred.

The idea

Every visit becomes a report: the site, the services, the work done in each area, the chemicals used, and the customer’s rating and sign-off. The office sees it as soon as the technician finishes.

What I built

  • The phone app

    An Expo app for technicians. They log in with a one-time code, pick the site, services and areas from bottom sheets, then hand the phone to the customer.

  • Customer sign-off

    The customer rates the visit and confirms it with a signature or a one-time code. The code goes by Zalo when their number has it, by SMS otherwise.

  • The web admin

    A React app for the office: customers, sites, contacts, staff by region, chemicals, and every report, with PDF export.

  • The backend

    A Rails 8 API with roles, email invitations for new staff, and search across reports by number, site or contact.

What I learned

The person holding the app is standing in a customer’s kitchen. Every extra tap shows. I put the usual choice first and kept each step to one sheet.