Location: Remote
Work Modality: 100% Remote (Europe & Latin America)

About the Opportunity

At 5411 Hub, a headhunting firm specialized in senior and expert-level technology roles across LATAM, the U.S., and Europe, we are partnering with a leading global company in blockchain infrastructure and decentralized technologies to recruit a Software Engineer Expert.

This is a core engineering role, focused on the evolution of a blockchain client (node/client software) that supports EVM compatibility, consensus improvements, and secure, high-performance protocol features.

The Role (explained clearly)

This is not a typical Web3 application or dApp development role.
It is a deep engineering position, centered on:

• Core blockchain client development
• EVM compatibility at the protocol level
• Consensus, execution, and performance improvements
• Backend, low-level engineering in Java

You will work alongside highly experienced blockchain engineers in a fast-paced, research-driven environment, building Web3 infrastructure at the foundation level, where architectural and implementation decisions directly impact network security, stability, and scalability.

Key Responsibilities

• Develop new features for the blockchain client using Java as the primary language.
• Analyze complex technical requirements, which may include:
  • Ethereum consensus changes
  • Bitcoin scripts
  • Internal research papers and protocol proposals
• Design and implement features following best practices for security, scalability, and performance.
• Write clean, modular, well-tested code using solid object-oriented design principles.
• Actively participate in peer reviews and technical discussions to continuously improve code quality and development processes.
• Write simple Solidity smart contracts to validate and test client features at the EVM level (testing purposes only, not production dApp development).
• Share research outcomes and technical insights with distributed, global teams.
• Maintain and expand CI/CD automation, including GitHub Actions pipelines.

What You Bring (and what it really means)

Strong Technical Background

• 5+ years of professional experience in Java, or equivalent experience with JVM-based languages (Kotlin, Scala, Gradle) or C++.
• 3+ years of experience working on core blockchain components, such as:
  • Node or client development
  • Consensus or execution layers
  • Protocol-level infrastructure
• Solid understanding of Ethereum or Bitcoin architecture, including:
  • Smart contract execution models
  • Consensus mechanisms
  • Core protocol design
• Ability to reason deeply about security, performance, and edge cases in complex distributed systems.
• Strong command of data structures (trees, graphs, etc.) and their practical application in system design.
• Basic experience with Solidity, with a clear understanding of how to interact with smart contracts (primarily for testing and validation).
• Familiarity with CI/CD pipelines and automation tools such as GitHub Actions.

👉 When the role refers to “core blockchain components”, it means critical infrastructure, not surface-level application development.

Professional Profile & Collaboration

• Hands-on engineer with strong ownership and accountability.
• Clear technical communicator and collaborative team player.
• High standards for code quality, security, and documentation.
• Comfortable working in a fully remote, global, and diverse environment.
• Fluent English (spoken and written) is required.

What’s Offered

• Competitive compensation aligned with expert-level seniority.
• 100% remote work from Europe or Latin America.
• Access to global coworking spaces.
• Strong work–life balance, including generous vacation, sick leave, and parental leave policies.
• Annual learning budget for training, certifications, and language courses.
• Opportunity to work on mission-critical blockchain infrastructure with global impact.
• Monthly allowance for contractors to support connectivity and well-being.