Available for new projects

Hi, I'm
Shantanu
Kumar Singh

Senior Android Developer with 5 years shipping production apps on Android & Flutter. Built Priya — an AI Hindi voice bot with Twilio + GPT-4o-mini + Sarvam TTS. Specialist in Firebase, WebRTC, and clean architecture.

Android · Kotlin Flutter · Riverpod · BLoC · GetX iOS · Desktop · Web Firebase OpenAI · Gemini Priya Voice Bot WebRTC · Paytm UPI
Get in Touch → View My Apps
5+
Years Experience
4+
Live Apps Published
3+
Companies Served
4
Platforms (Android · iOS · Web · Desktop)
About

Building Mobile Experiences
That Actually Ship

I'm a Senior Android Developer based in Delhi, India, with a track record of building production-ready apps used by real consumers across India. From e-learning platforms with IoT attendance to devotional apps with 4.8★ ratings, I've shipped across diverse categories with a consistent focus on performance, stability, and user delight.

My tech stack spans Android (Kotlin + Jetpack), Flutter for Android, iOS, Web & Desktop using Riverpod, BLoC, and GetX, Firebase, WebRTC real-time calling, Paytm UPI payments, and AI APIs including OpenAI and Gemini. I also built Priya — a fully deployed AI Hindi voice bot powered by Twilio, GPT-4o-mini, and Sarvam AI TTS, handling live inbound calls with natural Hindi conversation.
📍
Location
Delhi, India
✉️
Email
shantanu0092@gmail.com
📱
Phone
+91 8588823519
🟢
Status
Open to opportunities
▶️
Play Store
DV PRO TECHNOLOGIES
🍎
App Store
Teleone on iOS
🌐
Web App
BhagyaG Astro
Skills

Technical Arsenal

Android Development
KotlinJetpackMVVM HiltCoroutinesFlow LiveDataRoom DBRecyclerView WorkManager
Flutter · Cross-Platform
DartRiverpodBLoC GetXAndroidiOS WebDesktopFlutterFlow
AI & Voice Bots
Priya Voice BotTwilioGPT-4o-mini Sarvam AI TTSaiohttpGemini API ChatGPT APIPrompt Engineering
Firebase
AuthFirestoreRealtime DB StorageFCMCrashlytics AnalyticsFunctions
Realtime & Payments
WebRTCICE / STUN / TURNWebSockets Paytm SDKPhonePeCashfree UPI
Architecture & Tools
MVC MVP MVVM Clean ArchitectureMulti-module RetrofitOkHttpGit PostmanPlay StoreApp Store Connect CrashlyticsFigma
Experience

Where I've Built Things

Senior Android Developer
Teleone Consumer Product Pvt. Ltd. · DV PRO TECHNOLOGIES PRIVATE LIMITED
Feb 2023 – Present · Delhi
Android (Kotlin) Flutter Riverpod BLoC GetX Firebase WebRTC Paytm UPI iOS MVVM
  • Developed and maintained production apps: Teleone Consumer Product, BhagyaG, Kaam24, and Ram Ram Ji.
  • Implemented real-time WebRTC audio/video calling with ICE, STUN/TURN, adaptive bitrate, and reconnection.
  • Integrated Paytm UPI payment SDK with secure backend verification and failure recovery.
  • Built Flutter apps targeting Android, iOS, Web, and Desktop using Riverpod, BLoC, and GetX.
  • Managed Play Store and Apple App Store publishing, versioning, and compliance.
  • Reduced crash rate by 40% using Crashlytics analysis, strict API handling, and performance tuning.
▶ Play Store — DV PRO TECHNOLOGIES 🍎 App Store — Teleone iOS
Android Developer
Saptrishi Infosystem Pvt. Ltd.
Aug 2020 – Sep 2022 · Lucknow
Android (Kotlin) Firebase IoT REST APIs MVVM
  • Built Outomate Shiksha — an e-learning platform with IoT-based biometric attendance tracking.
  • Developed HMS Hotel Management System and MB Club apps from scratch.
  • Integrated IoT attendance hardware with Firebase Realtime Database for live analytics dashboards.
  • Implemented MVVM + Repository improving code scalability and long-term maintainability.
App Support & Training (Trainee)
Gmng Entertainment Pvt. Ltd.
Dec 2017 – Jul 2020 · Gurgaon
Mobile App Testing User Support Issue Tracking
  • Trained users on mobile app usage, gameplay features, wallet modules, and navigation flows.
  • Reproduced gameplay bugs, payment failures, and login issues; documented findings for developers.
  • Provided customer onboarding support and resolved user-facing app issues.
Published Apps

Live on Play Store & App Store

📱
Teleone Consumers
Android iOS Flutter
Consumer services platform with real-time features, Firebase sync, WebRTC calling, and Paytm UPI integration.
▶ Play Store → 🍎 App Store →
✨
BhagyaG Astro
Android iOS Flutter Web Desktop
Astrology & live call app with WebRTC, AI horoscope generation (Gemini + ChatGPT), UPI payments, cross-platform Flutter.
▶ Play Store → 🌐 Web App →
💼
Kaam24
Android
★ 4.0 · Play Store
Job search & hiring platform connecting workers, daily wage earners, and employers across India.
▶ View on Play Store →
🙏
Ram Ram Ji
Android
★ 4.8 · Play Store
Top-rated devotional app featuring Mandir songs, prayers, aarti, and daily spiritual content.
▶ View on Play Store →
Projects

More Things I've Built

⭐ Featured Project
🤖
Priya — AI Hindi Voice Bot
Inbound Hindi voice bot answering live phone calls via Twilio PSTN. 10-state aiohttp state machine with static keyword replies (0 ms) and GPT-4o-mini NLP fallback. Sarvam AI TTS (bulbul:v2 · hi-IN) for natural Hindi speech. Orders logged to Google Sheets.
PythonTwilioGPT-4o-mini Sarvam TTSaiohttpGoogle Sheets Render.com
🎓
Outomate Shiksha
E-learning + IoT biometric attendance system for schools and colleges. Firebase real-time analytics dashboard for administrators.
KotlinIoTFirebase
🏨
HMS Hotel Management
Full-featured hotel management system with room booking, billing, guest management, and staff coordination modules.
KotlinFirebaseREST APIs
🎮
MB Club
Consumer membership and loyalty app with gamified rewards, Firebase integration, and clean modern UI.
KotlinFirebaseFigma
Contact

Let's Build Something Great

✉️
Email
shantanu0092@gmail.com
📱
Phone
+91 8588823519
📍
Location
Delhi, India
▶️
Play Store
DV PRO TECHNOLOGIES
🍎
App Store
Teleone — iOS App
🌐
Web App
BhagyaG Astro
Currently Available

Open to New Projects

Whether you're building a new app from scratch, scaling an existing product, or integrating AI & voice into mobile — I'd love to hear about it. Let's connect!