d
donggeonlee

Donggeon L

@donggeonlee

Senior Go, golang Backend Engineer, Payments and Blockchain

Corea del Sur
Inglés, Coreano
Parte de la información aparece en idioma inglés.
Sobre mí
Senior Backend Engineer (Go(golang), Python) with 15+ years of experience, 8 in Go. I build payment systems (card payments, subscription billing, on-chain USDC) and blockchain services on Ethereum, Hyperledger Fabric, and Cosmos SDK, from backend design to mainnet launch. Stack: Go(golang), Python, Node.js, gRPC, Kubernetes, AWS, GCP, MySQL, ClickHouse, Stripe, PayPal, Authorize.Net, Solidity. 6 years of remote work with teams in the US, Sweden, Israel, and China. Message me before ordering to discuss your project.... Lee más

Habilidades

d
donggeonlee
Donggeon L
desconectado • 

Revisa mis servicios

API e integraciones
I will develop a go backend API with payment integration
DeUSD 50 / proyectoMás información
Aplicaciones descentralizadas (dApps)
I will build defi and blockchain backends, smart contracts and web3 integrations
DeUSD 50 / proyectoMás información

Porfolio

Experiencia laboral

WildfireART

Blockchain Developer

WildfireART • Freelance

Jun 2025 - Dec 2025 • 6 mos

• Took over a non-operational blockchain service and resolved critical issues across the Node.js and EVM stack, including Ethereum, Base, and USDC transaction integrations. • Fixed critical bugs in Solidity smart contracts and refactored and optimized them, reducing gas costs and bringing contract size under the EIP-170 (24KB) deployment limit. • Maintained the frontend’s Web3.js integration to keep it in sync with backend and smart contract changes. • Redesigned the system architecture to align with the original product requirements and completed preparations for mainnet launch.

Home_- Bnei Baruch Kabbalah Academy

Back End Developer

Home - Bnei Baruch Kabbalah Academy • Freelance

Jul 2022 - Jul 2024 • 2 yrs

• Maintained Go microservices for event and broadcast registration, orders and payments (Pelecard), and user profiles synced with Keycloak. • Built a lecture subtitles and slides service in Go with Keycloak OIDC authentication and document ingestion from a media archive. • Built Python automation that bulk-downloads Zoom recordings across account users via Server-to-Server OAuth. • Deployed services with Docker and GitLab CI, with automated staging and manual production releases. • Developed the initial frontend, implementing core pages and user flows.

VegaX

Backend / Blockchain Developer

VegaX • Tiempo completo

Feb 2021 - Aug 2022 • 1 yr 6 mos

• Led the Konstellation (DARC) Cosmos SDK chain from mid-development to mainnet launch, including mainnet genesis and network configuration. • Built custom Cosmos SDK modules for an exchange-rate oracle and token issuance, and upgraded the chain’s Cosmos SDK with IBC and CosmWasm support, including IBC connection to Cosmos Hub. • Built a DARC↔BNB Smart Chain token bridge in Go (API, block parser, and worker services) with an order state machine, expiry handling, and automatic retries. • Operated validator and full nodes for the network. • Maintained the oracle price feeder, an explorer REST API with Redis caching, and network tooling for localnet, testnet, and mainnet deployment.