Donggeon Lee

Migrated a monolithic Go server to microservices on GCP, developing shared libraries for auth, logging, and CDN. Developed and maintained payment, subscription, billing, and tax services integrated with Stripe and PayPal.

Took over a non-operational blockchain service, resolving critical issues across Node.js and EVM stack, including Ethereum, Base, and USDC integrations. Fixed critical bugs in Solidity smart contracts, reducing gas costs and bringing contract size under EIP-170 limit.

Built a real-time chat system in Go using Redis Pub/Sub for message fan-out and SSE for streaming messages to clients. Implemented connection lifecycle management and message delivery handling for long-lived client sessions.

Rebuilt a FastAPI-based resource allocation API for a Bittensor GPU compute subnet, enabling clients to allocate, manage, and monitor GPU resources. Implemented spec-based miner matching, allocation flows, and decryption of RSA-encrypted SSH credentials.

Maintained Go microservices for event registration, payments, and user profiles synced with Keycloak. Built a lecture subtitles service and Python automation for Zoom recordings.

Led development of a Go-based token trading application on the Xelis blockchain, implementing token exchange flows. Built backend services for wallet management and transaction processing, integrated the Xelis SDK, and deployed with Docker.

Developed a Go-based YouTube video management server with gRPC APIs. Implemented backend workflows for video ingestion and metadata management, optimizing video processing through parallel uploads and batch processing.

Developed a FastAPI backend system for parking citation payments, integrating Authorize.net and Heartland payment gateways. Implemented payment transaction workflows, error handling, and reporting.

Led the Konstellation (DARC) Cosmos SDK chain from mid-development to mainnet launch, including genesis and network configuration. Built custom Cosmos SDK modules for an exchange-rate oracle and token issuance, and upgraded the chain with IBC and CosmWasm support.

Maintained and optimized Go and Python microservices for a solar installation company's operations management system. Developed a Telegram chatbot to automate customer interactions and managed deployment on GCP.

Led the development and launch of a blockchain-based credit data service on Ethereum and Hyperledger Fabric. Led ICO preparation and developed smart contracts for the entire lifecycle, from token sales to service launch.

Migrated a monolithic PHP server to Go microservices and containerized them on Kubernetes. Implemented a Backend for Frontend (BFF) layer in Go to aggregate microservice APIs for client applications.

Implemented internationalization (i18n) for a Bitcoin debit card service's localization server, including database migrations to support multilingual content.

Ported the messaging app's backend services to Go, building client-facing APIs for proxy number provisioning and customer management, and integrating with an Elixir-based message delivery server. Built an internal ERP platform to support business operations.

Developed Go tools to automate translation preparation workflows. Built CMS and localization management systems for translation projects.

Maintained annual iOS and Android conference agenda apps for an IBM event. Maintained Firestone Complete Auto Care vehicle service apps and developed the AAOS Musculoskeletal Exam – Spine app for iOS and Android.

Developed an in-house ERP application covering internal business operations, including accounting and credit management.

Bachelor's Degree in Computer Software Engineering from Kwangwoon University.