Kiho Nguyen

Full-stack & Blockchain Engineer

Press Enter ↵ to continue · Esc to skip

Available for select engagements

KihoNguyen

Full-stack & Blockchain Engineer · aka Yugo

I build payment infrastructure and on-chain systems — from Soroban and Move smart contracts to production payment gateways and the interfaces on top of them.

View workGet in touch
#01024TypeScript0xd90c17db
#01025Rust0xdf0c214d
#01026Move0xc00bf080
#01027Solidity0xde0c1fba
#01028NestJS0xc30bf539
#01029GraphQL0xca0c003e
#01030Next.js0xc30bf539
#01031React0xdf0c214d
#01032PostgreSQL0xdd0c1e27
#01033FastAPI0xcb0c01d1
#01034Stellar0xde0c1fba
#01035Aptos0xcc0c0364
1036 blocks · finalized
01 / Selected work

Builton-chain,shippedtoproduction

Stellar · Fintech

UCTalent Payment Rails

Dual-rail payout infrastructure for a live hiring platform. Domestic checkout runs through 9Pay with e-invoicing; cross-border payroll settles USDC via Soroban escrow and a SEP-31 corridor into VND bank accounts.

  • Idempotent payment-intent API with signed webhooks
  • Soroban milestone escrow & atomic commission split
  • Onshore VND settlement in under 10 seconds
  • NestJS
  • GraphQL
  • PostgreSQL
  • Soroban
  • SEP-31
sim://payment-railslive
Domestic · VNDClientcheckoutIntentidempotent9PaygatewayWebhookHMAC ✓e-InvoiceissuedCross-border · USDCEmployerUSDCSorobanescrowMilestonereleaseSEP-31anchorVND Bank< 10sshared ledger · reconciliation
  • FIATea0c32intent.created pi_4f2a · 12,500,000 VND
  • CHAINe60c2cescrow.lock 1,200 USDC · 3 milestones
  • FIAT3a0cb09pay.ipn signature verified
  • CHAINee0c38milestone#2 released → split 95 / 5
  • FIATea0c32invoice.issued WinInvoice #00172
  • CHAINf00c3csep31.payout settled 8.4s · 30.49M VND

Aptos · EVM

Oreka

Binary-option prediction market implemented natively on Aptos Move and Solidity, with a comparative study of object storage, oracle models and gas behaviour.

  • Resource-oriented market objects
  • Pyth pull oracle vs Chainlink push
  • Long/short pool pricing and settlement
  • Move
  • Solidity
  • Pyth
  • Chainlink
  • React
sim://orekalive
MarketBTC ≥ 68,000
Mark67752.5
OraclePyth · pull
40
15%P(long)
LONG 1.83×2.20× SHORT
TVL 33,730 USDC
    Pyth update verified on-chainSHORT pool settles · 2.20× payout

    Aptos · Move

    Futarchy Protocol

    Governance by prediction markets: every proposal spawns PASS and FAIL conditional markets, and the protocol executes whichever outcome the market prices higher over time.

    • Conditional vault — 1 USDC mints 4 outcome tokens
    • Gaussian AMM with volatility-adjusted fees
    • TWAP resolution, DIVE AI oracle & optimistic dispute window
    • Aptos Move
    • Gaussian AMM
    • TWAP
    • Oracle adapter
    sim://futarchylive
    1 USDC
    PASS·YESPASS·NOFAIL·YESFAIL·NO
    PASS TWAP 0.500FAIL TWAP 0.500 · +3% premium
    MintTradeTWAP checkDIVE · 24h window
    FAIL · proposal rejected
    02 / Case study

    Trust,securedbycodeandAI

    Base · AI · Security

    Bloody-Roar

    A trust-minimised bounty marketplace where identity, money and evidence are all verifiable. Wallet-native auth, contract-held rewards and an AI layer that guards conversations and assists — never replaces — human arbitration.

    • Next.js 14
    • GraphQL Yoga
    • Prisma
    • PostgreSQL
    • Solidity 0.8.24
    • Base Sepolia
    • LLM router
    Layer 01 / 05

    Wallet-native identity

    Sign-In with Ethereum replaces passwords. GitHub OAuth links a verified developer profile that acts as reputation collateral instead of capital.

    • EIP-4361 signed nonce
    • GitHub verification
    • Zero-stake for developers

    bloody-roar.app wants you to sign in with

    your Ethereum account: 0xe00c…f30c

    URI: https://bloody-roar.app

    Chain ID: 84532 · Base Sepolia

    Nonce: fb0c4d61235eaf3d

    sig 0xd60c13229f02f49e8ca678e1940f2a1e…

    ✓ recovered signer matches · session issued · GitHub linked

    Interactive simulation · illustrative data

    Rules-first, model-second redactionHash-only provider logsHuman-in-the-loop arbitrationSignature-based sessions
    03 / About

    Calmincode,relentlessindelivery

    Silver wolf artwork — personal emblem
    Emblem · Silver Wolf

    I work where money meets code: settlement flows, escrow logic and the product surfaces people actually touch. My focus is correctness first — idempotent APIs, auditable state machines and contracts that fail safely.

    01

    Smart Contracts

    Escrow, prediction markets and governance primitives on Stellar Soroban, Aptos Move and EVM.

    • Soroban
    • Move
    • Solidity
    • Oracles
    02

    Payment Infrastructure

    Payment intents, gateway integration, webhooks and e-invoicing for a live recruitment platform.

    • NestJS
    • GraphQL
    • PostgreSQL
    • 9Pay
    03

    Product Engineering

    Type-safe frontends with motion, realtime features and AI-assisted workflows.

    • Next.js
    • React
    • FastAPI
    • LLM
    04 / Experience

    Thechainsofar

    Block #0040xda0c196e4d
    2026 — Present

    Software Engineer — UCTalent

    Payment and invoicing backend, Stellar disbursement gateway (APAC Stellar Hackathon 2026), UC Yield on Base.

    Block #0030xc60bf9f243
    2025 — 2026

    Blockchain Engineer — Independent · Aptos & EVM

    Oreka prediction market and Futarchy V2 — conditional vaults, Gaussian AMM and TWAP-based resolution.

    Block #0020xcd0c04f745
    2025 — 2026

    Capstone Lead Developer — Bloody-Roar

    Decentralised bounty marketplace: escrow design, wallet identity, AI chat guard and evidence-backed arbitration.

    Block #0010xcb0c01d1e8
    Education

    Information Systems — Duy Tan University · CMU Program

    Systems integration, databases, mobile and e-commerce engineering.

    05 / Contact

    Let'sbuildsomethingthatsettles.

    trongkhoidev@gmail.com
    LinkedIn ↗GitHub ↗X @trongkhidev ↗