Most "what is Flutter" articles stop at the marketing line: one codebase, many platforms. That is true, but it is not enough to make an architecture decision for a two-sided marketplace, where you are shipping a buyer app, a seller experience, an admin backend and a payment flow that all have to agree with each other.

This post looks at Flutter the way an engineer evaluating it for a marketplace build would: what actually happens at runtime, where the framework saves you work, where it costs you, and which questions to answer before you run flutter create . It is based on the Journeyhorizon guide What is Flutter App Development: Guide for Marketplace Founders , reorganised as a technical checklist.

The runtime model in three pieces

Flutter is Google's open-source UI framework for building mobile, web and desktop apps from a single codebase. Three components explain almost every trade-off you will run into.

1. Dart, compiled ahead of time

Your app is written in Dart.…