Ruslan Gunawardana— Toronto, ON
SeniorFull-StackEngineer
Available for new roles
TypeScript · Node.js · React · AWS
01.About
I build scalable products on the Node.js ecosystem — 10+ years in TypeScript, Node.js, React, NestJS, GraphQL, and event-driven microservices across PostgreSQL, Redis, Kafka, and AWS/GCP. Recently I delivered a D2L education platform for a large Canadian charity and shipped generative-AI products powered by fine-tuned LLMs on serverless AWS. I've cut API latency 40%+, improved reliability at scale, and spent 6+ years leading teams for North American clients.
Open Source
55 merged upstream PRs, including a code fix in nestjs/graphql, feature work on Zilliqa's kaya, and a fix in eslint-plugin-compat.
github.com/exarus →Education
- Master's Degree in Software Engineering — Igor Sikorsky Kyiv Polytechnic Institute, Ukraine, 2018
- Bachelor's Degree in Software Engineering — Igor Sikorsky Kyiv Polytechnic Institute, Ukraine, 2017
02.Projects
A few things I've shipped — click any screenshot for the full-size version.
eWizard — multi-channel content platform for pharma
Viseven · 2024 – 2025An enterprise platform where 150+ pharma and life-science companies create, edit, and publish email, web, and in-app content from a single editor. I built Vue.js editor features, rebuilt core Express.js services (40%+ faster APIs), and led the feature team.
- TypeScript
- Node.js
- Express.js
- Vue.js
- REST APIs
- AWS
PIXIO — social platform & voxel studio
Trendformer · 2021 – 2023A social platform for 3D pixel artists built around PIXIO magnetic blocks — artist profiles with followers and likes, an in-browser voxel builder, and an e-commerce storefront, shipped across web, iOS, Android, and an admin dashboard.
- TypeScript
- Node.js
- NestJS
- GraphQL (Apollo Federation)
- Kafka
- Redis
- Elasticsearch
- PostgreSQL
- Vue.js
Pleasuredomes — generative-AI companion platform
R&D Center Winstars.AI · 2023 – 2024An AI companion platform (18+) where every character is generated end-to-end: fine-tuned LLM conversations, Stable Diffusion avatar pipeline, and ElevenLabs voice — orchestrated on fully serverless AWS (Lambda, Step Functions) with a Next.js frontend.
- TypeScript
- Next.js
- AWS Lambda
- Step Functions
- LLM fine-tuning
- Stable Diffusion
- ElevenLabs
DMEX — decentralized derivatives exchange
CodeRiver · 2018 – 2021A first-of-its-kind DEX for derivatives trading with up to 100x margin and non-custodial funds — smart-contract order settlement, a pro trading terminal with live order book and charts, and MetaMask wallet integration. Handled 1,500+ transactions during initial rollout.
- JavaScript
- Vue.js
- Web3.js
- Ethereum smart contracts
EtherMium — ERC-20 trading terminal
CodeRiver · 2018 – 2021A decentralized trading terminal where any ERC-20 token can be traded without listing — TradingView charting, live order book and trade feed, and on-chain balances held by smart contract.
- JavaScript
- Vue.js
- Web3.js
- TradingView
03.Experience
Senior Full-Stack Software Engineer
EPAM Systems — EdTech: D2L (Desire2Learn) education platform for a large Canadian charity
- Led backend modernization of a D2L (Desire2Learn) education platform used by a large Canadian charity to deliver training to thousands of learners nationwide — cutting page load times 30%+ and improving reliability at scale.
- Migrated legacy data to PostgreSQL, redesigned schemas, and introduced structured migrations, improving query performance by 35% with zero data loss across repeated migration runs.
- Built accessible, reusable UI with Lit web components and TypeScript/Express.js REST APIs powering learner-facing course and content workflows, meeting WCAG standards.
- Owned features end-to-end with a distributed Canadian team — shipping 75 features across 17 sprints with zero critical production incidents, accelerated by AI-assisted development (Claude, Cursor, GitHub Copilot).
- Node.js
- TypeScript
- Express.js
- REST APIs
- PostgreSQL
- Lit
- Python
- Django
- AWS
- Docker
- GitHub Actions
Senior Full-Stack Software Engineer · Team Lead
Viseven — eWizard: multi-channel content platform for global pharma
- Built core features of the eWizard editor in Vue.js — the flagship authoring component of an enterprise multi-channel content platform delivering email, web, and in-app content for 150+ pharma and life-science companies.
- Improved content-customization workflows, reducing content creation time by 30% while preserving consistent multi-channel rendering.
- Rebuilt core Express.js services, cutting API response times by 40%+ and increasing throughput at peak.
- Led the feature team — sprint planning, code reviews, and mentoring — coordinating delivery with product stakeholders across time zones.
- Node.js
- TypeScript
- Express.js
- Vue.js
- REST APIs
- AWS
Senior Full-Stack Software Engineer (Contract)
R&D Center Winstars.AI — Contract: generative-AI chatbot platform
- Designed and shipped an AI chatbot powered by a fine-tuned LLM, delivering personalized, context-aware conversations end-to-end.
- Built a generative-AI avatar pipeline creating characters from prompts via Stable Diffusion, with ElevenLabs-driven voice and text-to-speech for natural spoken interaction.
- Architected a fully serverless AWS backend (Lambda, Step Functions) orchestrating LLM inference, image-generation, and voice-synthesis workflows with pay-per-use scaling.
- Delivered a responsive Next.js frontend with streaming AI responses and real-time voice playback.
- Node.js
- TypeScript
- Next.js
- React
- AWS (Lambda, Step Functions, API Gateway, S3, Route 53)
- LLM fine-tuning
- Stable Diffusion
- ElevenLabs
- prompt engineering
Senior Full-Stack Software Engineer · Tech Lead
Trendformer — Social platform for 3D artists
- Transformed a static landing page and CMS into a scalable social platform across web, iOS, Android, and an admin dashboard.
- Designed the backend architecture for an event-driven platform of 5 microservices with collaborative editing, multi-device sync, conflict resolution, and AI-assisted content selection.
- Introduced Elasticsearch, gRPC, Kafka, and Redis — cutting search response times by 40%; optimized BullMQ jobs and Apollo Federation GraphQL APIs, reducing data-fetch time by 40%.
- Integrated a Shopify-based e-commerce layer, and led a 4-person team as sole senior — cutting average feature cycle time from 14 to 9 days.
- Node.js
- NestJS
- Express.js
- TypeScript
- GraphQL (Apollo Federation)
- Kafka
- Redis
- Elasticsearch
- PostgreSQL
- BullMQ
- Vue.js
- Python
- Django
- Docker
- AWS
Lead Frontend Software Engineer
CodeRiver — Decentralized crypto exchange & Web3 products
- Launched a decentralized crypto exchange built on Solidity smart contracts, handling 1,500+ transactions during initial rollout; promoted to Lead Frontend Engineer.
- Led a team of 4 developers to operational readiness in 4 months through agile execution, code reviews, and CI/CD practices.
- Built a Vue.js / Web3.js crypto game that scaled to 50K+ players, with real-time on-chain state sync and optimistic transaction UI.
- JavaScript
- Vue.js
- Web3.js
- Solidity
- Python
- Django
- PostgreSQL
Full-Stack Software Engineer · Team Lead
Ineffable Innovations — Early-stage AI startup (volunteer); wound down after funding fell through
- Led a 4-person team end-to-end (planning, reviews, delivery) building an AI microcomputer application in Python / React / TensorFlow.js.
- Reduced cloud costs by $20K/year by moving ML inference on-device with TensorFlow.js.
- Grew the beta program to 400 testers, driving product iteration directly from structured user feedback.
- Python
- Django
- JavaScript
- React
- TensorFlow.js
- PostgreSQL
Software Engineer
Netcracker Technology — OSS/BSS & telecom solutions
- Developed presales proof-of-concepts for OSS/BSS and MANO/SDN telecom solutions, from concept through customer presentation.
- Delivered 3 high-demand features ahead of schedule by aligning development with shifting presales priorities.
- Represented engineering in direct discussions with major telecom stakeholders across 4 international business trips.
- Java
- Spring Framework
- Java EE (Jakarta EE)
- JavaScript
- jQuery
- React
- PostgreSQL
- MySQL
- Oracle Database
04.Skills
Languages
- TypeScript
- JavaScript (ES2023+)
- Python
- Java
- SQL
- HTML5/CSS3
- Bash
Backend
- Node.js
- Express.js
- NestJS
- Fastify
- GraphQL (Apollo Federation)
- REST APIs
- gRPC
- WebSocket
- microservices
- event-driven architecture
- serverless
- BullMQ
Frontend
- React
- Next.js
- Vue.js
- Lit
- Redux
- TanStack Query
- Tailwind CSS
Data
- PostgreSQL
- MySQL
- Redis
- MongoDB
- Elasticsearch
- DynamoDB
- Kafka
- Debezium
- RabbitMQ
- Prisma
- TypeORM
Cloud / DevOps
- AWS (Lambda, Step Functions, ECS, S3, SQS/SNS, EventBridge, API Gateway, RDS, CloudWatch, Route 53, Cognito)
- GCP (Cloud Run, GKE, Pub/Sub, BigQuery, Cloud SQL)
- Docker
- Kubernetes
- Terraform
- CI/CD pipelines
- GitHub Actions
- GitLab CI
AI / ML
- LLM integration & fine-tuning
- prompt engineering
- RAG
- AI agents
- LangChain
- Stable Diffusion
- ElevenLabs TTS
- TensorFlow.js
- AI-assisted development: Claude Code (agentic workflows)
- Cursor
- GitHub Copilot
- Kiro (AWS)
Testing
- Jest
- Vitest
- React Testing Library
- Supertest
- Cypress
- Playwright
- TDD
Observability / Security
- OpenTelemetry
- Prometheus
- Grafana
- Sentry
- Datadog
- ELK
- OAuth 2.0/OIDC
- JWT
- RBAC
- OWASP