Senior Java Blockchain Engineer
Senior Java Blockchain Engineer
Java + BTC + ETH + Solana + TRON
Full-time, EU timezone (±)
Location: Europe (preferred)
Project Overview
Building an internal wallet technology platform for custodial operations across Bitcoin, Ethereum, Solana, and TRON. The goal is to replace a fragmented setup of multiple vendor-specific tools with a unified, client-owned stack — consolidating policy engines, wallet registries, and governance frameworks into a single system.
Platform scope: policy and governance · wallet management · transaction construction and execution · signing coordination
Responsibilities
Design and develop a unified custodial wallet platform from the ground up
Build and maintain wallet management, transaction construction, and signing coordination modules
Implement policy and governance layers for multi-chain operations
Integrate blockchain protocols: Bitcoin, Ethereum, Solana, TRON
Ensure security, scalability, and reliability of the custody infrastructure
Consolidate existing vendor-specific tools into a single client-owned stack
Requirements (Must-have)
Strong hands-on Java development experience in production environments
Proven experience with blockchain protocols — BTC, ETH, Solana, TRON
Deep understanding of wallet infrastructure: key management, signing flows, transaction lifecycle
Experience building or integrating custodial / non-custodial wallet systems
Solid understanding of cryptographic primitives (signing schemes, key derivation)
EU timezone availability, full-time commitment
Nice to Have
Experience with HSM or MPC-based signing coordination
Familiarity with multi-chain wallet registries
Prior work on fintech or crypto custody platforms
Tech Stack
Java · Bitcoin · Ethereum · Solana · TRON · Wallet Infrastructure
Hiring Process
Intro call → Technical discussion → Offer
Start: ASAP
Duration: Long-term (8+ months)
Required languages
| English | B2 - Upper Intermediate |
| Ukrainian | Native |