Skip to content
← Back to portfolio

Walid Islam

Flutter and Mobile App Developer (iOS, Android) · engineer, lead and technical product roles

Berlin, Germany | snapnsolve.apps@gmail.com | walidislam.space | linkedin.com/in/walidislam | github.com/walidx64

Open to full-time, contract and freelance work | Berlin, hybrid, or remote across Europe, the UK, Australia and New Zealand | Willing to relocate with visa sponsorship and relocation support

Summary

Mobile app developer with 5+ years of professional experience and 15+ shipped apps. Founder and sole developer of four consumer apps live on the App Store and Google Play (Berlin ArtWalk, Barcelona Art Walk, Nature Unlock, Nibbl) with 10,000+ combined downloads, built end to end: product, Flutter app, native Swift and Kotlin code, backend, payments, store publishing and paid acquisition. Lead developer of the INU university app (iOS, Android, iPad, web) with AI tutoring on RAG, Azure AI Studio and OpenAI. Previously shipped EdTech (Complori), industrial IoT (core sensing) and e-commerce (Shoppium) apps in teams.

Skills

  • Mobile: Flutter, Dart, iOS (Swift), Android (Kotlin), React Native, Flutter Web, cross-platform development, Bloc/Cubit, Hydrated Bloc, MobX, GetX, Provider, Freezed, get_it, injectable, go_router, Dio, SQLite, Hive, offline-first, Google Maps, Apple Maps, GPS and geocoding, routing and polylines, background audio and recording, video playback and FFmpeg, PDF and EPUB readers, PDF generation, Markdown and LaTeX rendering, WebView, QR codes, image compression, localisation (slang, intl), push notifications, deep linking, Live Activities, in-app purchases, subscriptions (RevenueCat), AdMob, in-app review, App Store Connect, Google Play Console, App Store Optimization (ASO)
  • Backend & data: Supabase, Firebase (Firestore, Auth, Storage, Cloud Functions, App Check, Crashlytics, Analytics, Messaging), Laravel (PHP, Sanctum, Horizon, Redis queues, JSON:API, spatie permissions), Node.js, REST APIs, GraphQL, PostgreSQL, Docker and docker-compose, Protocol Buffers, WebSockets, Rust via flutter_rust_bridge
  • AI & ML: Retrieval-Augmented Generation (RAG), Azure AI Studio, Azure Machine Learning, Azure Data Factory, OpenAI API, Google Gemini, Google Vision API, Google ML Kit (on-device image labelling), computer vision, LLM summarisation, AI personalisation, AI training and facilitation (Intel AI for Future Workforce)
  • Native & devices: iOS Screen Time API (FamilyControls), Android UsageStats and Accessibility APIs, Bluetooth Low Energy (BLE), Live Activities, HealthKit
  • Quality & delivery: Unit tests, widget tests, bloc_test, mocktail, Patrol and integration_test suites, Sentry and Firebase Crashlytics, PostHog and Firebase Analytics, Meta SDK app events, OneSignal and Firebase Cloud Messaging, FVM, build_runner codegen, CI/CD, Git, Agile/Scrum, clean architecture, WorkManager and background tasks, Sign in with Apple and Google, Meta Ads, ASO and competitor research, Next.js landing pages for five apps, Three.js, Jaspr
  • Languages: English (fluent), German (working proficiency), Bengali (native)

Experience

Mobile Application Developer, INU

Sep 2023 – Present | Cologne, North Rhine-Westphalia, Germany | Remote

  • Lead development of the INU App, a cross-platform mobile application (iOS, Android, iPad, tablet & Web app) serving as the central learning hub for Germany's innovative online university
  • Architect and implement AI-powered educational features using Retrieval-Augmented Generation (RAG) pipelines integrated with Azure AI Studio and OpenAI APIs
  • Developed the technology foundation for AI-based professor avatars providing 24/7 student support with interactive, on-demand learning assistance
  • Build and maintain full-stack solutions using Flutter/Dart for mobile, Vue.js for Admin, and Laravel backend services with REST APIs
  • Leverage Microsoft Azure ecosystem including Azure Data Factory and Azure Machine Learning for data pipelines and ML model deployment

Mobile Application Developer, core sensing GmbH

Jul 2023 – Sep 2023 | Darmstadt, Hesse, Germany | Remote

  • Developed cross-platform mobile application (iOS & Android) for real-time visualization and configuration of industrial IoT sensor data via Bluetooth Low Energy (BLE)
  • Implemented efficient data serialization using Protocol Buffers (protobuf) for high-performance communication with IoT sensor nodes
  • Built features supporting simultaneous connection with up to 4 measuring amplifiers, live dashboards with configurable intervals, and CSV export functionality
  • Implemented comprehensive test coverage using Patrol framework for native UI automation and integration testing

Mobile Application Developer, Complori (acquired by cleverly)

Jan 2023 – Jun 2023 | Berlin, Germany | Hybrid

  • Developed Flutter-based mobile learning application supporting children aged 10-16 in learning programming through adaptive, gamified experiences
  • Built and shipped new features end-to-end using Flutter and Firebase ecosystem including Cloud Firestore, Firebase Authentication, and Cloud Functions
  • Collaborated with design team using Figma to translate UI/UX concepts into polished, child-friendly interfaces with high usability standards
  • Wrote comprehensive unit and widget tests ensuring code quality and application stability with performance optimization
  • Contributed to mission-driven startup focused on making coding education accessible to children across Europe

Mobile Application Developer, Shoppium

Jan 2021 – Jan 2023 | Remote | Remote

Developed and maintained the Shoppium e-commerce mobile application.

Earlier: Customer Support Analyst, 2degrees, Auckland (Nov 2019 – Nov 2020). Software Asset Management Consultant, Accordo Group, Auckland (Oct 2018 – Jul 2019).

Projects (founder and sole developer)

Berlin ArtWalk | Oct 2024 – present | www.berlinwalk.art

  • Founder and sole developer of a Berlin travel-guide app: audio guides at 100 landmarks, 8 curated audio walks, turn-by-turn and AI-built walking tours, daily events feed, 215+ galleries, 450+ street-art locations. #1 App Store result for "Berlin street art" and top 10 for "Berlin travel guide" (DE, Oct 2026).
  • 10,000+ downloads across the App Store and Google Play, 4.6+ star rating; monetised with ads, vendor promotion and RevenueCat purchases.
  • Flutter, Firebase, Google Maps, Gemini; listed on Product Hunt.

Nature Unlock | Apr 2025 – present | www.nature-unlock.com

  • Screen-time app that blocks distracting apps until the user photographs real nature; AI verifies the photo.
  • Native iOS Screen Time (FamilyControls) and Android accessibility code inside a Flutter app; Scroll Blocker, Focus Mode, website blocking, streaks, Live Activities, AI meditations.
  • Free plus Premium subscription via RevenueCat; featured on Product Hunt, Uneed and Peerlist; 4.6+ star rating.

Nibbl | Feb 2026 – present | www.nibbll.app

  • Newsletter and RSS reader with a swipeable card feed, personal @nibbll.app inbox, Gemini AI summaries, OPML import, offline library and cross-device sync.
  • iPhone, iPad and Android in seven languages; free tier plus lifetime Pro purchase; growth through Meta and Instagram ad campaigns I run.
  • Architecture: Cloudflare Email Routing to a Cloudflare Email Worker to a Supabase Edge Function (Deno) to Postgres with row-level security, full-text search and triggers; Gmail API ingestion with 300+ remote filter rules; Sentry, PostHog, RevenueCat, Google Gemini.

Barcelona Art Walk | Jan 2026 – present | apps.apple.com/us/app/barcelona-art-walk-mural-map/id6757681567

  • Re-used the Berlin ArtWalk codebase to launch a second city travel guide in weeks: 300+ artworks and galleries, audio tours at 89 landmarks including the Gaudí route, daily events, turn-by-turn tours. Top 10 App Store result for "Barcelona city guide" (DE, Oct 2026).

BULU: Pet Care & Vet Finder | Aug 2026 – present | www.bulu.pet

  • Pet-care app for Malaysia and Singapore: vet and clinic finder on a map, pet profiles, care reminders, health records, community feed and a Gemini care assistant. Launched on the App Store and Google Play (5.0 App Store rating at launch) on the ArtWalk engine, with a Flutter Web admin panel and Next.js site.

Education and certifications

  • Intel Digital Readiness: Lead Facilitator, AI for Future Workforce Program, Germany (July 2026). Intel certification covering machine learning, deep learning, computer vision, NLP, AI inferencing, AI solution building and AI ethics, plus train-the-trainer facilitation. Certificate
  • Bachelor of Computer Science, Unitec Institute of Technology, Auckland, New Zealand (2018)
  • ITIL Foundation (IT Service Management)
  • NZQA Level 4 Certificate in Information Technology