How We Built Kormi Koi: A Real-Time Service Marketplace App in Flutter
A case study on building an on-demand service marketplace with real-time tracking, bidding, e-KYC verification and an in-app wallet using Flutter, Express.js and MongoDB.
Finding a trusted plumber or electrician is still mostly word of mouth. Kormi Koi set out to fix that: one platform where people post a job, compare bids from verified professionals and track them in real time. Here is how our team built it.
The problem
The local service industry is fragmented. Customers don't know who to trust, and skilled workers struggle to find steady jobs. The app needed to build trust and transparency on both sides.
Key features we built
- Job posting and bidding: customers post detailed requests, compare bids and choose professionals based on ratings and profiles.
- Real-time location tracking: customers see the provider on the way, just like a ride-hailing app.
- One app, two roles: seamless account switching lets a user be a customer and a service provider in the same app.
- e-KYC verification: workers are verified before they can take jobs, which is the core of the trust model.
- In-app wallet: secure payments between customers and providers.
- Real-time chat and role-based access control.
Tech stack
- Flutter for iOS and Android from one codebase
- Express.js microservices so each part (jobs, payments, chat) can scale independently
- MongoDB for flexible job and profile data
- WebSockets for live tracking and chat
What we learned building a marketplace app
- Trust features come first. Verification and ratings matter more than any visual feature in a two-sided marketplace.
- Design both sides of the marketplace separately. Providers and customers have very different daily workflows.
- Real-time is an infrastructure decision. Planning WebSocket architecture early avoided a painful rewrite later.
Building a marketplace or on-demand app?
If you are planning a service marketplace, booking platform or on-demand app, we have done the hard parts before. Book a free consultation with PiRhoTech, or with Solidy.io if you are outside Bangladesh.