Reduzer
Beta

Flutter Web Developer

Onsite - Reduzer Office
contract
senior

Position Overview

We are seeking a Flutter Web Developer to build complex Flutter web applications. You will take high-level requirements and transform them into minimal, intuitive UIs. This role requires deep expertise in Flutter Web and strong design instincts.

Key Responsibilities

  • Build Flutter Web applications, including embeddable apps that integrate into third-party websites via iframe
  • Implement bidirectional communication between Flutter and host pages using postMessage and JavaScript interop
  • Build runtime theming systems that adapt to different branding requirements (colors, typography, spacing)
  • Handle cross-frame event management, prevent conflicts with host sites (scroll, focus, event bubbling, z-index)
  • Translate verbal requirements into polished, usable UI directly in Flutter
  • Write modular, maintainable code using Provider for state management
  • Ensure embeds don't break host sites and host sites don't break Flutter
  • Integrate with backend APIs and asynchronous chat services
  • Write and maintain Flutter/Dart unit tests across multiple service levels
  • Navigate and contribute to a large monorepo codebase

Technical Requirements

Flutter & Dart

  • 2+ years shipping production Flutter Web apps (not mobile ports)
  • Deep understanding of Flutter Web rendering (WASM + Skia) and widget rendering mechanics
  • Proficiency with Flutter's LayoutBuilder and responsive design patterns for web component contexts
  • Strong grasp of key packages: provider, get_it, Dio, go_router, and current (non-deprecated) HTML rendering packages
  • Experience with Flutter unit and widget testing
  • Solid understanding of design patterns: Singleton and DI patterns via get_it

JavaScript & Web Interop

  • Proficiency in JavaScript interop (dart:js_interop, postMessage, cross-frame event listeners)
  • Experience building and embedding Flutter-based web components into third-party host pages
  • Knowledge of iframe security (sandbox attributes, cross-origin constraints)
  • Ability to handle cross-frame event conflicts (scroll, focus, z-index, event bubbling)

Architecture & State

  • Experience building dynamic runtime theming systems (colors, typography, spacing injected at runtime)
  • Provider for state management, must be able to model loading/error/success states cleanly
  • Familiarity with JSON-driven configuration models for UI customization
  • Ability to navigate and contribute to large multi-package monorepos, prior experience with Melos is a plus

APIs

  • Experience consuming REST/JSON APIs for personalized content and product delivery
  • Familiarity with Shopify Storefront API / GraphQL for client-side product queries and headless CMS content delivery is a plus

Ideal Candidate Profile

  • Strong UI/UX sensibility, portfolio shows clean, minimal interfaces with obvious user flows
  • "Less is more" design philosophy, your work requires few revision cycles
  • Makes design decisions independently without Figma mockups
  • Proactive and comfortable working from verbal briefs
  • Can deliver under time constraints with minimal supervision
  • Comfortable navigating and contributing to large, complex codebases