Mobile Engineer

Hi, I am Rayhanul Islam

Mobile products shouldn't just work.They should feel seamless.

I build practical, production-ready mobile products with Flutter, turning complex business requirements into reliable experiences people can actually use.

View my workSee my specialtyGet in touch

Delivered mobile products across 10+ countries

  • USA
  • Canada
  • Australia
  • Italy
  • Finland
  • South Africa
  • Indonesia
  • Philippines
  • Saudi Arabia
  • Kuwait
  • Bangladesh
  • USA
  • Canada
  • Australia
  • Italy
  • Finland
  • South Africa
  • Indonesia
  • Philippines
  • Saudi Arabia
  • Kuwait
  • Bangladesh

Plus home-market delivery from Bangladesh

Selected work

Products shipped across markets

Production Flutter apps with store presence, architecture, and the messy parts of real delivery.

Kadipay banner: fix your car now and pay in installments

Fintech

Kadipay

Flutter rebuild of a React Native product for automotive repair and pay-later workflows.

Flutter rebuild in progress

Tested · Patrol E2E on critical flows, plus widget and integration tests

Git · Feature branches, pull-request review, lint enforced before merge

In progress

FlutterClean ArchitectureCI/CDPaymentsFirebasePostHogMaps
MDBriefcase LMS System banner with mobile home screen

EdTech

MDBriefcase

One Flutter codebase powers 7 LMS apps across 3 businesses, with Moodle SCORM and a JS↔Dart bridge.

7 apps from one codebase

Tested · Patrol E2E on critical flows, plus widget and integration tests

Git · Feature branches, pull-request review, lint enforced before merge

FlutterClean ArchitectureCI/CDMoodleSCORMWordPressGetXSalesforce
eCourier services banner: Line Haul, Merchant Delivery, and Person 2 Person Delivery

Logistics

eCourier Suite

Lead Flutter engineer on a four-app logistics suite: Merchant, Agent, Branch, and P2P.

4 apps live on both stores

Git · Feature branches and pull-request review

FlutterClean ArchitectureCI/CDREST APIFCMQR ScanningPayments
F1tCloud fitness brand banner

Fitness

F1tCloud

Gym SaaS with member and trainer apps. Flutter flavors ship a branded store app in a day.

Branded store apps from one flavor pipeline

Git · Feature branches and pull-request review

FlutterClean ArchitectureFlavorsREST APIFirebase
Sydney Disability Support banner: Your NDIS Journey, Our Personalised Support

Healthcare

Sydney Disability Support

NDIS platform for participants and support workers: booking, live status, shift tools, and notifications.

Live on App Store and Google Play

Git · Feature branches and pull-request review

FlutterFirebaseGoogle Places
Stallo Fried Chicken app feature banner with mobile home screen

Food Delivery

Stallo

Flutter food-booking app for a Finnish brand: multi-branch sync, payments, add-ons, and store releases.

Direct-to-consumer apps live in Finland

Git · Feature branches and pull-request review

FlutterClean ArchitectureREST APIPayments

How I build

Why this work holds up in production

Flutter delivery with architecture, store shipping, and the engagement modes teams actually need.

5+

Years building mobile products

25+

Products shipped

6+

Domains in production

10+

International markets

Clay illustration of production Flutter

Production Flutter

Flutter and Dart are the center of gravity: feature-based architecture, multi-flavor apps, and long-lived products that ship to the stores.

Clay illustration of app architecture

Architecture and shipping

Clean Architecture, CI/CD, App Store Connect, and Google Play Console. The work includes the release, not just the code.

Clay illustration of flexible engagement

Flexible engagement

Contract, full-time, part-time, or project-based. Comfortable overlapping US, EU, and APAC hours.

Clay illustration of existing and greenfield codebases

Existing codebases and greenfield

Join an architecture already in production, or start a product from a blank repo. Both are normal delivery modes.

Flutter & Dart: Core Specialty

Production Flutter delivery is the center of gravity: architecture, shipping, and long-lived mobile products.

FlutterDartGetXFeature-based architectureMulti-flavor apps

Architecture

Clean ArchitectureSOLID & DRY principlesRepository patternMVCAPI contracts

Tools & Platforms

App Store ConnectGoogle Play ConsoleCI/CDFirebase SuiteFastlaneGitHub ActionsFigmaPostmanXcodeAndroid StudioGit

Product Domains

LMS / EdTechFintech / PaymentsLogisticsERP / Business OperationsSocial / CommunityLocation Tracking / MapsService & AutomotiveHealthcareFood deliveryGame / Crypto rewardsIoT / Bluetooth hardware

Core tools

  • Flutter
  • Dart
  • Firebase
  • GitHub Actions
  • Fastlane
  • App Store
  • Google Play
Also comfortable with

Languages

PythonJavaKotlinSwiftC++SQL

Frameworks & Libraries

DjangoFlaskNestJSReactReact NativeBootstrap

Databases & Data

MySQLPostgreSQLMongoDBFirestoreSupabaseNoSQL

Depth

Production depth beyond the framework

How I work

From first call to the store, and after

A simple, predictable path for agencies and product teams. You always know what comes next.

  1. 01

    Discovery call

    We go through the product, the users, and the deadline. We also decide whether I join your existing codebase or start greenfield. Calls fit your hours across US, EU, and APAC overlap.

  2. 02

    Architecture & plan

    Clean Architecture, a feature-based structure, the repository pattern, and clear API contracts. We agree on all of this before the first feature starts.

  3. 03

    Build in sprints

    Production Flutter for Android and iOS, delivered in small, reviewable steps. A custom lint package keeps the code consistent.

  4. 04

    Test & release (CI/CD)

    GitHub Actions and Fastlane pipelines ship to App Store Connect and Google Play. The release is part of the work, not an afterthought.

  5. 05

    Support & scale

    Crash reporting, offline-first sync, and production support after launch, so the app stays reliable as it grows.

Experience

Roles, products, and the work inside them

Department Lead who defines core app architecture and owns full-lifecycle Flutter delivery across an LMS ecosystem and Kadipay, from requirements through integrations, testing, CI/CD, and production support. Reviews pull requests on a feature-branch workflow and enforces the internal Flutter lint package in review.

EdTech / LMS

MDBriefcase

  • Single Flutter codebase powers 7 apps across 3 businesses: MDBC, RXBC, and BMA
  • Integrates 3 WordPress CMS instances and 2 Moodle LMS systems
  • WebView with JS↔Dart bridge: separate Android/iOS implementations behind a unified interface, communicating with Moodle APIs
  • Feature-based GetX architecture with repositories, typed DTOs, and domain entities
  • Course enrollment, SCORM tracking, surveys, webinars, forums, and engagement pipelines
  • Patrol end-to-end tests on critical flows, with widget and integration tests

Fintech / Service & Automotive

Kadipay

  • Flutter rebuild of a React Native app for service, repair, and pay-later automotive workflows
  • Animation-heavy UI with custom motion design for key product flows
  • Financing flows with pre-approval, payment plans, and production payment integrations
  • Merchant discovery, invitations, reviews, ratings, and service acceptance
  • Maps/location, Firebase Analytics, push notifications, PostHog, and hardened security controls
  • Patrol end-to-end tests on critical flows, with widget and integration tests

Tech stack

FlutterDartClean ArchitectureCI/CDOffline-firstAdd-to-AppGetXMoodleSCORMFirebasePostHogAmazon Payment ServicesApple PaySalesforce Marketing CloudGitHub ActionsFastlane

Blog

Notes from the build

Plain write-ups of problems I solved in production Flutter apps, with small code examples.

All posts

Contact

Let's connect

Rescue, scale, or ship a Flutter app. Let’s talk about turning it into a practical, production-ready product.

EngagementOpen to hourly, part-time, or project-based contracts. Rate negotiable based on scope.

AvailabilityFlexible across time zones, adapts to project needs (US/EU/APAC overlap comfortable).

Codebase fitEqually comfortable joining an existing architecture or building greenfield.

contact@rayhanulislam.spaceDownload CV

Replies within 24 hours.

Flexible across US / EU / APAC overlap. Happy to schedule calls that fit your working hours.

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