Publication
Context Aware Applications and Complex Event Processing Architecture
https://www.toptal.com/developers/app/context-aware-apps-and-complex-event-processing
Rahul is available for hire
Hire RahulRahul Devaskar
Verified Expert in Engineering
React Developer
Perth, Western Australia, Australia
Toptal member since October 3, 2014
Bio
Rahul is a professional software engineer with leadership experience and expertise in building full-stack React and Node.js applications and streaming data analytics solutions. He has designed and developed an innovative context-aware advertising platform using Node.js and machine learning techniques, which the Silicon Valley-based data analytics company acquired later.
Portfolio
Quizzy
TanStack Router, Elixir, Phoenix, OpenAI, Artificial Intelligence (AI)...
LC & D innovations PTY LTD
React, APIs, API Integration, Image Generation, OpenAI API, Gemini API, Next.js...
Cooke & Associates Inc dba CANDA
React Native, Full-stack, AI SDK, AI Chatbots, Expo, Vercel, OpenAI...
Experience
- React - 9 years
- Node.js - 7 years
- React Native - 6 years
- TypeScript - 6 years
- Claude Code - 2 years
- ChatGPT API - 2 years
- Claude - 2 years
- AI SDK - 1 year
Work Experience
Senior Full-stack Engineer
2026 - 2026
Quizzy
- Built a Kahoot-style quiz app that requires no sign-ups. Quickly setup quiz in seconds and start playing.
- Developed a classroom mode for quizzes. Teachers can use Quizzy to gamify classroom sessions.
- Built a highly scalable platform using Phoenix and fly.io to support 100s of live quizzes with 15+ players each.
Technologies: TanStack Router, Elixir, Phoenix, OpenAI, Artificial Intelligence (AI), AI Agents, OpenAI API
Full-stack Developer
2025 - 2026
LC & D innovations PTY LTD
- Built an AI image generation/modification app that takes multiple images and merges them into a single image.
- Added an AI workflow to overlay text on images. The user can select an image and text. Generated layers that they can drag and rearrange before the final merge.
- Built a Next.js-based designer app to merge images using AI.
Technologies: React, APIs, API Integration, Image Generation, OpenAI API, Gemini API, Next.js, flux kontext model, TypeScript, Ollama, OpenAI, Artificial Intelligence (AI), AI Agents
React Native Full-stack Developer
2025 - 2026
Cooke & Associates Inc dba CANDA
- Built an edtech React Native app with videos, a quiz, and an AI tutor. The app helps aviators become skilled pilots.
- Implemented a fully customizable course module builder with a rich text editor and an AI-powered Word document parser to quickly manage the course delivered via a mobile app.
- Developed a RAG-powered AI agent workflow to enable AI tutor chat in the app. This workflow is fully customizable using an Admin panel to manage RAG, design prompts, test prompts, etc.
- Built an AI-powered news curator back end to regularly fetch the aviation-specific news using deep search.
Technologies: React Native, Full-stack, AI SDK, AI Chatbots, Expo, Vercel, OpenAI, Artificial Intelligence (AI), AI Agents, OpenAI API
Senior Full-stack Developer
2025 - 2025
Self-employed
- Built a negative gearing calculator for real estate investors.
- Developed a Next.js 15 web app to manage a property portfolio.
- Added the cron jobs and web scrapers to implement property value tracking and property buy/sell events.
Technologies: Next.js, Drizzle ORM, PostgreSQL, TypeScript, OpenAI, Artificial Intelligence (AI), AI Agents, OpenAI API
Senior Software Engineer
2024 - 2025
Coverly AI
- Built a fully AI chat-driven multilingual application in the insurance and healthcare industry.
- Worked on an AI chatbot powered by a voice and chat UI that caters to English, Spanish, and Hindi users.
- Created an AI chatbot that drastically reduces the application time and allows users to converse with each other, providing support via chat and voice.
- Used RAG (deep search) for the AI workflow to search for medications and medical conditions.
- Made the AI back end switch between models for optimal performance and higher API throughput.
Technologies: AI Chatbots, VoiceBot, Voice Chat, TypeScript, ChatGPT, Gemini, Redis, AI SDK, Full-stack Development, CTO, Fractional CTO, Artificial Intelligence (AI), AI Agents, OpenAI API
Front-end Engineer
2024 - 2025
CHUNKSHACKLE PTE. LTD.
- Developed a DAO marketplace from scratch using Next.js and Tailwind.
- Built a code to interact with Ethereum smart contracts using Wagmi and Viem.
- Created a token auction functionality in the buy/sell token app using Next.js.
Technologies: React, Next.js, TypeScript, Front-end, Tailwind CSS, Web3, Blockchain, Cryptocurrency, Wagmi, Ethereum Smart Contracts
Senior Software Engineer
2023 - 2025
Open Corridor
- Built a science-based impact management tool to help businesses and governments build resilience in communities, the economy, and the environment.
- Developed a React/WebGL application from scratch. The technologies used were TypeScript, WebGL, web workers, Rust, WebAssembly, React, and GraphQL.
- Worked on a unique app. The APIs are heavy (over 20MB). I designed the UI to handle large datasets while keeping the UX snappy. The front end is powered by web workers and WebGL/GPU threads.
Technologies: TypeScript, Deck.gl, Big Data, React, HTML5, Tailwind CSS, Node.js, Next.js, XState, UI Libraries, UI Frameworks, Design, D3.js, ChatGPT API, Front-end Development, Web Worker, Fractional CTO
Senior React Engineer
2022 - 2025
Evrchat
- Built a WebRTC video chat app to connect support agents and customers. This React app is a white-labeled app for video chat support B2B clients.
- Designed and developed the agent video chat page in React, Tailwind CSS, and WebRTC client.
- Rearchitected the old code to be more performant and robust. Used state machines to manage complex video chat events and connections.
Technologies: React, WebRTC, Video Chat, Docker, Tailwind CSS, REST, WebSockets, UI Libraries, UI Frameworks, Design, Radix UI, Framer Motion, Front-end Development
Senior Full-stack Developer
2023 - 2024
FGRMTech Pte Ltd
- Developed a Next.js app with a dynamic form to support multiple visa applications.
- Built an affiliates system to support visa application tracking and affiliate discounts.
- Created an admin portal to manage visa requirements for multiple countries and allow admins to manage visa documents.
Technologies: Next.js, TypeScript, Tailwind CSS, HTML, React, UI Frameworks, Front-end Development
Full-stack JavaScript and TypeScript Engineer
2022 - 2023
AutoGrab Pty Ltd.
- Built a Next.js (TypeScript) based fully customizable responsive dashboard with drag-and-drop and resizable data and charts widgets for a SaaS automotive platform.
- Created a SOAP-based client to consume the external SOAP service.
- Developed a back-end logic in Node.js to run a cron job for fetching stats.
Technologies: TypeScript, JavaScript, Node.js, React, Next.js, GraphQL, Google Cloud, Apollo, MongoDB, PostgreSQL, Framer, GSAP, CSS, HTML5, Full-stack, UI Frameworks, Front-end Development
Node.js Expert
2022 - 2023
Nerd Collective, LLC
- Built React/Next.js-based logins using MetaMask and Coinbase wallets.
- Developed a Node.js-based back end to handle WebSocket's stream from OpenSea.
- Created cron jobs to process data and derive analytics, such as an average floor price, profit and loss, and a sell wall.
Technologies: Node.js, Web3.js, Ethers.js, JavaScript, Blockchain, Non-fungible Tokens (NFT), Tailwind CSS, Full-stack, React, UI Frameworks
TV Developer
2021 - 2022
Endeavor
- Helped build the TV apps for the client, including Apple TV, Android TV, LG TV, Samsung TV, and Amazon Fire TV. The apps are created using React Native and TypeScript.
- Built the spatial navigation feature in the new apps for TVs.
- Helped migrate the legacy code to the new applications.
Technologies: React, React Native, TV, tvOS, Android TV, HTML5, Xcode, UI Frameworks
React Native Developer
2020 - 2021
Yara
- Built React Native-based Android and iOS apps for the client.
- Added new features to the existing apps and built a Bluetooth monitoring app from scratch.
- Implemented an automated test set up to ensure the QA of the React Native app is manageable and maintainable.
Technologies: React, React Native, HTML5, Xcode, Node.js, Android, iOS, Bluetooth Low Energy (LE)
React Native Developer
2020 - 2020
Protas Tech, LLC
- Designed and built a React Native app powered by a GraphQL back end.
- Built a back-end Node.js GraphQL API server backed by a Firestore database.
- Released the app for download on the US App Store.
Technologies: React Native, Firebase, GraphQL, Xcode, React, Tailwind CSS, Figma, Node.js, Firebase Hosting, Cloud Firestore, Full-stack Development
React Native Developer
2019 - 2020
Wardrobe Luxury Fashion
- Built an image-heavy React Native app from scratch to rent luxury fashion items.
- Developed a performant React Native app that included high-resolution images and animations.
- Created a payment processing feature using Stripe APIs.
Technologies: React Native, Figma, CSS, Xcode
React Native Developer
2019 - 2020
Highlighter, Inc.
- Collaborated with a React Native team to build a React Native-based iOS app for book and podcast highlighting.
- Built the podcast highlighting feature in the existing React Native app.
- Developed a GraphQL-based API server using Node.js and TypeGraphQL. The back-end database was Firebase.
Technologies: Node.js, GraphQL, React Native, Xcode, Full-stack
React Native Developer
2018 - 2019
Mosaic
- Added new features to the existing React Native app and fixed bugs in old code.
- Used React Native to create iOS and Android builds.
- Contributed to UI/UX designs for a React Native app.
Technologies: React Native, Xcode
Full-stack Engineer
2016 - 2018
Spotbeat
- Created a React-based app to search for interesting local pubs and restaurants.
- Developed a back-end API platform using Node.js, GraphQL, PostgreSQL, and PostGIS.
- Built a social network app with wall posts, comments, likes, reactions, chat, and follow users' features.
Technologies: PostgreSQL, Node.js, GraphQL, React, CSS, Full-stack
Node.js API Server Developer
2015 - 2016
Primedice
- Developed a Node.js-based API platform and the logic behind games.
- Used Redis and PostgreSQL to build a highly scalable back end.
- Designed and built a secured API for blackjack, minesweeper, plinko, and bustabit games.
- Created a Bitcoin deposit and withdraw API and user accounts API.
- Designed and built a chat server using Socket.IO, including chat groups, media attachments, and emojis.
Technologies: Socket.IO, PostgreSQL, Redis, Node.js, Amazon EC2, Bitcoin
Software Engineer
2015 - 2015
RBD
- Developed the entire link-sharing app from scratch.
- Built an intelligent post-creation form with fast autocomplete.
- Created a Node.js-based API server to serve the website and apps.
- Programmed a responsive web app with social network features such as posts, comments, and follow-ups.
- Wrote a real-time chat and comments engine with mentions and emoji support.
Technologies: MongoDB, Node.js, CSS, HTML5, Full-stack, Amazon EC2
Full-stack Developer
2015 - 2015
Gogogab
- Built a real-time event management system with push notifications.
- Developed a scalable API server using Node.js, Express.js, and PostgreSQL.
- Created an AngularJS-based web app to manage events.
Technologies: Node.js, CSS, HTML5
CEO
2014 - 2015
Aponomy
- Built an app for Western Australia to get the best fuel prices.
- Designed and developed a mobile app to track fuel prices.
- Created an RSS parser and cron jobs to schedule regular updates.
Technologies: Android, iOS, RSS Feeds, Ionic, CSS
Node.js Developer
2014 - 2015
Coinucopia
- Created firmware for Bitcoin ATMs that run on ATM hardware.
- Built a secure API server for Bitcoin transactions.
- Developed a Node.js-based serial port communicator for camera and bill validator hardware.
- Built an AngularJS-based web application to display real-time Bitcoin prices and stats.
- Created infrastructure for AML and KYC of Bitcoin buyers.
Technologies: MongoDB, Bitcoin, Node.js
Software Innovator
2012 - 2014
Mobius Innovations
- Designed and developed a context-aware mobile advertising platform using machine learning and pattern recognition techniques.
- Built a highly scalable Node.js-based complex event processing engine for pattern matching in streaming sensor data such as location traces, bank transactions, weather, and social media events.
- Created an iOS and Android library that can be added to any mobile app to serve context-aware advertisements inside apps.
- Developed a data mining engine that provides semantic ontology-based mining of linked open data sources such as OpenStreetMap, DBpedia, and Freebase.
- Programmed an AngularJS-based front-end portal to design and deploy rules for pattern matching.
Technologies: Machine Learning, Redis, MongoDB, Node.js
Founder and CTO
2010 - 2012
AXS Solutions
- Founded a company for mobile payment facilitation.
- Designed and developed the entire Node.js-based push notification platform for mobile payment receipts.
- Developed a Node.js and Socket.IO-based front end to send notifications to mobile apps.
- Built an Android app for mobile payments and a web app to support user accounts.
- Created an API for integrating the mobile payment feature in third-party apps.
Technologies: Push Notifications, iOS, Redis, Node.js
IT Analyst
2005 - 2012
Tata Consultancy Services
- Built a system size estimator to predict future hardware requirements using the current load on the server.
- Created a SOAP application server to expose legacy services, written in C and COBOL, as web services use SOAP 1.2 protocol.
- Developed a testing framework for SOAP server integration testing.
- Built a WSDL generator in Java to auto-create WSDL for legacy services.
- Led the team of five developers and three testers.
Technologies: Web Services, C
Founder and CTO
2008 - 2010
Blackbull Investment Company
- Designed and built a stock market technical analysis web app that shows beautiful charts for various technical analysis indicators, such as MACD, TRIX, MA, and Stochastics.
- Built a web-based portfolio manager to track companies and set buy/sell triggers for stock prices.
- Created an SMS-based notification system to send buy/sell trigger notifications to mobile phones.
- Maintained a blog to explain technical analysis using stock market indicators.
Technologies: jQuery
Project History
Alchemist
Alchemist is a Node.js-based complex event processing framework. It matches patterns in various sensor data from mobile systems, bank transactions, and social media to detect credit card spending patterns.
Porsche OI 2019 - Semifinalist
I built a blockchain-powered secure digital key platform to create and share digital car keys. Users can use a Porsche mobile app to lock, unlock, and customize their cars. The keys can also be securely shared with friends or clients.
Fuelmate Android App
An Android app built using AngularJS and Ionic frameworks to find the best fuel prices in Western Australia. The app tracks fuel prices and helps users get the best fuel deals nearby. The users can set alerts in the app and be notified when the fuel price target is matched.
Context-aware Apps and Complex Event Processing
I wrote a blog post about context-aware mobile development. It outlines the design principles behind the complex event processing and analysis based on various sensor data. The blog post provides code samples to illustrate the event processing patterns.
Fuelmate for iOS
An iOS mobile app to get the best fuel prices in Western Australia. The app tracks the fuel prices daily and notifies users about the best prices around them. Users can also set price targets in the app to get notifications when their price criteria are met.
Complete Authentication Solution for Web Apps
A reusable module to instantly add a feature-rich user management system to any web app. It was built as a standalone authentication server for user management. A front-end demo was built using AngularJS.
Crypto Price Tracker
https://chrome.google.com/webstore/detail/crypto-price-tracker/fpkhlnacfhciopipcjpcjmkpldbogaeo/reviewsA crypto price tracker chrome extension to track live cryptocurrency prices and to get notifications for price changes. The extension has over 2000 active users and it supports prices in different fiat currencies.
React Native App
I assisted in building a React Native iOS app to connect college alumni users with new college grads for guidance and mentorship. The app helps new college grads to get mentorship and guidance during their enrolment process.
Learning Platform
https://learning-platform-smoky.vercel.appThis demo app was built using Next.js, TypeScript, Radix UI, Tailwind CSS, and Framer animations.
It features a video player with app router navigation and charts built using D3. The web app uses the latest Next.js app router.
It features a video player with app router navigation and charts built using D3. The web app uses the latest Next.js app router.
Education
2001 - 2005
Bachelor's Degree in Electrical Engineering
University Of Mumbai - Mumbai, India
Skills
Libraries/APIs
React, Node.js, GSAP, OpenAI API, Web Worker, jQuery, Socket.IO, Web3.js, WebRTC, D3.js, Framer Motion, Wagmi
Tools
Figma, Chrome Developer Tools, Sketch, Xcode, AI SDK, Drizzle ORM, Claude, Claude Code, ChatGPT, Expo, TanStack Router
Languages
TypeScript, GraphQL, CSS, JavaScript, HTML5, Swift, C, HTML, Elixir
Frameworks
React Native, Next.js, Tailwind CSS, Ionic, Deck.gl, Phoenix
Platforms
MacOS, Firebase, Amazon EC2, iOS, Blockchain, Ubuntu, Android, tvOS, Android TV, Bluetooth Low Energy (LE), Docker, Vercel, Ollama
Storage
Redis, MongoDB, PostgreSQL, Google Cloud, Cloud Firestore
Paradigms
REST
Other
Full-stack, Front-end Development, Framer, Code Architecture, UI Frameworks, Full-stack Development, Artificial Intelligence (AI), AI Agents, Apollo, UI Libraries, Design, ChatGPT API, CTO, Fractional CTO, OpenAI, Machine Learning, Push Notifications, Web Services, Bitcoin, RSS Feeds, TV, Ethers.js, Non-fungible Tokens (NFT), Complex Data Analysis, Chrome Extensions, Software, Big Data, XState, Firebase Hosting, Video Chat, WebSockets, Radix UI, AI Chatbots, Front-end, Web3, Cryptocurrency, Ethereum Smart Contracts, VoiceBot, Voice Chat, Gemini, APIs, API Integration, Image Generation, Gemini API, flux kontext model
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