Full-Stack Blockchain Engineer with Cross-Chain Expertise

Takehiko Kikuchi

Full-stack blockchain developer

********.**.***@*****.*** +818******** Minato City, Tokyo, Japan Profile

Full-Stack Blockchain Developer with strong experience across Bitcoin (UTXO, Taproot, node validation), Ethereum (EVM), Solana, Aptos (Move), Substrate, and CosmWasm. Skilled in building wallets (web, mobile, browser extensions), smart contracts, dApps, and secure backend services. Experienced in consensus mechanisms, validator operations, off-chain computation, and cross-chain architecture. Delivers clean, scalable systems using modern full-stack frameworks and crypto primitives, with a focus on performance, security, and high-quality user experience.

Professional Experience

Node Js Developer, Moontree, LLC

Moon Tree Consulting is a Service Disabled Veteran Owned Small Business 01/2025 – 02/2025

Orem, United States

•Developed a Node.js package to compile and broadcast P2SH and P2PKH transactions, enabling secure and efficient blockchain transactions.

•Implemented transaction serialization and script validation for multi-signature and standard Bitcoin-like transactions, enhancing wallet interoperability.

•Optimized blockchain wallet interactions by improving transaction flexibility and ensuring seamless integration with decentralized applications. Python Developer, Enso Consulting LLC

Business Consulting and Services

12/2024 – 01/2025

Utah, United States

•Developed a custom Python library for a Ravencoin fork, enabling advanced blockchain functionalities such as P2SH (Pay-to-Script-Hash)support and enhanced wallet management.

•Implemented secure P2SH transaction handling and multi-signature wallet support, improving flexibility and security in blockchain-based transactions.

•Optimized blockchain wallet interactions by extending Ravencoin’s core, ensuring seamless integration with custom transaction scripts and decentralized applications.

Full-stack Developer, Osmium

Driving Blockchain Innovation https://osmium.space 10/2024 – 01/2025

Czech Republic

•Designed and implemented a high-performance PostgreSQL database to support blockchain wallet operations, ensuring secure and efficient transaction management.

•Developed and optimized a Node.js backend using TypeScript to integrate blockchain functionalities, enhancing wallet performance and scalability.

•Implemented secure data storage and retrieval mechanisms for wallet transactions, improving blockchain interaction reliability and user experience. Web3 Developer, Ango-ya LLC

Web Consulting, Service Development

02/2022 – 07/2024

Fukuoka, Japan

•Designed and deployed Solidity smart contracts for DeFi protocols and DEX architectures, including Uniswap V3–style concentrated liquidity, fee tiers, and yield-farming mechanisms.

•Implemented secure wallet integrations (MetaMask, Trust Wallet, WalletConnect) to support seamless user authentication, transaction signing, and cross-chain interactions.

•Engineered core DEX functionalities such as swap execution, liquidity provisioning, position management, and pricing logic with a focus on performance and security.

•Managed end-to-end smart contract lifecycle, including architecture, testing, gas optimization, audits, and production deployments.

Full-stack Developer, Orixa LLC

A web3 company in Japan building DeFi, DEX, and multi-chain infrastructure. 10/2020 – 12/2021

Yokohama, Japan

•Built full-stack Web3 applications with React/Next.js and Node.js, supporting multi-chain wallet operations and real-time on-chain interactions.

•Developed backend services for blockchain event indexing, transaction processing, and liquidity/market data aggregation.

•Created reusable Web3 modules for wallet connections, transaction handling, and smart contract interactions across multiple networks.

•Implemented security best practices for key management, RPC communication, transaction validation, and signing workflows.

•Assisted in operating nodes and validators, including setup, monitoring, and optimization for network reliability and performance. Skills

Frontend

React, Next.js, TypeScript, TailwindCSS, Shadcn UI, MUI, Web3.js / Ethers.js,UI/UX for Web3 dApps

Blockchain

Bitcoin UTXO, Taproot, PSBT, Ethereum / EVM

(Solidity), Solana (Rust)

Aptos (Move), Substrate / FRAME, CosmWasm, Wallet

integration (MetaMask, WalletConnect, Trust Wallet), AMMs, DEX, liquidity, staking/farming,

Node/validator operations

Backend

Node.js, Express / Fastify, Python, PostgreSQL, Redis, REST & WebSocket APIs, Microservices architecture

Tools

Git / GitHub, Docker, CI/CD, Linux, Hardhat /

Foundry, Jest, Mocha

RPC tools & blockchain explorers

Education

Bachelor's Degree, Nanzan University

Achieved a GPA of 3.6 over the course of enrollment, graduating in the top 20% of the class

09/2017 – 12/2020

Languages

Japanese English

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