I've engineered software as an AI & Machine Learning Engineer and blockchain developer at Coullax, am pursuing my studies at IIT, and architect end-to-end AI/IoT tracking platforms like SoterCare using NestJS and Next.js.
Selected Work
Auto-synced from GitHubSoterCare
Cloud round-trips are too slow for real-time fall detection in elderly care. SoterCare is an end-to-end IoT health platform: an ESP32-S3 wearable runs on-device TensorFlow Lite fall detection and streams over BLE to a Raspberry Pi 5 edge gateway, with an MQTT pipeline into a NestJS + Next.js dashboard. Deployed to 1,000+ users since 2023.
Directed Graph Acyclicity Checker
Detects whether a directed graph contains a cycle using an adjacency-list representation and iterative sink-elimination (Kahn's topological sort), running in O(V + E). A clean demonstration of core CS fundamentals — the same DAG-validation logic used in build systems, task schedulers, and LLM agent workflow graphs.
Temp Mail SMTP
Free disposable email service built in Rust. Generate a temp inbox, receive and send real emails with DKIM signing. Auto-expires in 24 hours. No signup, no tracking.
3D Conversation Visualizer
Visualizing ChatGPT conversations in an interactive 3D space using Three.js and React Three Fiber.
Polymarket Arb
A production-grade latency arb bot targeting Polymarket BTC 5-minute and 15-minute up/down contracts
Html Pyscript
PyScript A beautiful interactive particle animation that creates a dynamic AWS logo effect using PyScript and HTML Canvas.
Tech Stack
Engineering CapabilitiesLanguages & Frameworks
Web3 & Blockchain
Backend & Infra
Databases & Hardware
Experience
2021 — PresentCoullax
AI & Machine Learning Engineer · Blockchain
Engineered REST APIs across 30+ country deployments; cut client onboarding 40%.
Freelance
Full-Stack Developer · Fiverr
Delivered 10+ full-stack projects with 5-star ratings for US, UK & EU clients.
Speaking & Community
Talks · Open SourceSpeaking
Amazon Bedrock: Your AI Vending Machine
Technical Presentation · Building GenAI apps on AWS Bedrock
Blockchain Architecture on Algorand & Solana
Technical Speaker · Web3 & consensus deep-dives
Community
Frequently Asked Questions
About SanjulaWho is Sanjula Herath?
Sanjula Herath is an AI & Machine Learning Engineer and blockchain expert based in Colombo, Sri Lanka, employed at Coullax. He builds production-grade Generative AI systems, LLM applications, RAG pipelines, autonomous AI agents, and DePIN infrastructure on blockchain. With 3+ years of engineering experience, his AI systems have reached 11,400+ real users across 30+ countries.
What does Sanjula Herath specialize in?
Sanjula Herath specializes in: (1) Generative AI — LLM pipelines, RAG applications, LangChain / LangGraph agents, OpenAI API, Gemini AI; (2) DePIN — Decentralized Physical Infrastructure on Algorand and Solana with on-chain AI; (3) Edge AI — TensorFlow Lite on ESP32 and Raspberry Pi for IoT health systems; (4) Full-stack — React, Next.js, FastAPI, gRPC, Go, Rust, TypeScript, Python.
What AI projects has Sanjula Herath shipped to production?
Sanjula Herath has shipped four production AI systems: (1) ChatGPT Visualizer — a 3D spatial conversation graph using React Three Fiber, with 10,400+ real user interactions; (2) SkillChecker — an AI interview platform using the OpenAI API for automated candidate evaluation and scoring; (3) SoterCare — a dual-device IoT wearable with TensorFlow Lite fall detection, deployed to 1,000+ real users; (4) Nomads — an AI-powered travel companion for Sri Lanka built with React Native and Go.
Is Sanjula Herath available for hire or AI collaboration?
Sanjula Herath works at Coullax as an AI & Machine Learning Engineer and blockchain expert in Colombo, Sri Lanka, and also takes on independent consulting engagements. He is open to AI engineering roles, strategic AI/blockchain collaborations, and consulting on production GenAI systems, RAG pipelines, and DePIN infrastructure, and is available for remote work globally. Contact: sanjula692@gmail.com or linkedin.com/in/sanjulaherath.
What tech stack does Sanjula Herath use for AI development?
Sanjula Herath's AI/ML stack: LangChain, LangGraph, TensorFlow, Scikit-Learn, OpenAI API, Gemini AI, Hugging Face, PyTorch. Languages: Python, TypeScript, Go, Rust. Backend: FastAPI, NestJS, gRPC, WebSockets, Node.js. Frontend: React, Next.js, React Native, Three.js. Blockchain: Solidity, Algorand SDK, Solana Web3.js. Infrastructure: Docker, AWS, Google Cloud, PostgreSQL, MongoDB, Kubernetes.
Where is Sanjula Herath located?
Sanjula Herath is located in Colombo, Western Province, Sri Lanka (6.9271°N, 79.8612°E). He works at Coullax, a technology company, and is available for remote work worldwide and open to relocation for senior AI engineering positions.
What is Sanjula Herath's experience with LangChain and RAG?
Sanjula Herath has hands-on production experience building RAG (Retrieval-Augmented Generation) pipelines and LangChain/LangGraph agents. His work includes embedding-based retrieval systems, vector database integration, multi-step agentic workflows, and LLM orchestration deployed in real applications with thousands of active users.
What is DePIN and what is Sanjula Herath's expertise in it?
DePIN stands for Decentralized Physical Infrastructure Networks — blockchain protocols that tokenize and govern real-world hardware infrastructure. Sanjula Herath is one of the few engineers combining AI with DePIN, building on-chain AI systems on Algorand and Solana that bridge physical IoT sensor data with decentralized smart-contract infrastructure.
What makes Sanjula Herath's work unique?
Most engineers specialize in either AI or blockchain; Sanjula Herath works at the intersection of both. He combines production Generative AI (LLM pipelines, RAG, LangChain agents) with DePIN and on-chain AI on Algorand and Solana, and extends it down to hardware through edge AI (TensorFlow Lite on ESP32 and Raspberry Pi). This full-stack range — from smart contracts to neural networks to embedded devices — lets him ship end-to-end systems few individuals can build alone.
How can I contact or hire Sanjula Herath?
You can reach Sanjula Herath by email at sanjula692@gmail.com, on LinkedIn at linkedin.com/in/sanjulaherath, or on GitHub at github.com/sanjulaonline. He is open to AI & machine learning engineering roles, blockchain and DePIN collaborations, and independent consulting on production GenAI, RAG, and on-chain AI systems, and is available for remote work worldwide.