Blockchain Backend Engineer (Rust / Polyglot) (Middle-Senior)

We are looking for a true Polyglot Engineer to join our team for a long-term collaboration. In the fragmented world of Web3, the ability to bridge different technologies is a superpower. We need a specialist who can architect and build the critical off-chain infrastructure that powers decentralized applications. If you are proficient in Rust but comfortable diving into C++, Python, and Node.js to get the job done, this role is for you.

Who are we?

We are Out Of The Box Systems: a Ukrainian team of passionate, battle-tested engineers and creators united by one goal—delivering real results with clarity, precision, and autonomy. We champion a flexible, pragmatic approach over rigid, static processes. While our roots and primary team are in Ukraine, we collaborate with top talent from various labor markets. We specialize in demanding fields like Rust-first development, AI Engineering, and Computer Graphics, blending performance, security, and innovation into every project. We are deeply invested in the growth of our team members, believing that a person's ability to learn and their openness to feedback are the true keys to long-term success. Our team thrives on solving hard problems and doing the heavy lifting so our clients don’t have to.

Workload

• Full-time, remote collaboration.
• Flexible schedule, with expected availability for team syncs.
• Project-based workload with a focus on clear deliverables.

Responsibilities

• Design, implement, and maintain high-performance backend services and indexers using Rust as the primary language.
• Integrate with diverse blockchain nodes and legacy systems, utilizing C++ for performance-critical modules or native bindings.
• Develop robust APIs and tooling scripts using Node.js and Python to ensure seamless interaction between on-chain data and client applications.
• Architect scalable data pipelines that can handle the asynchronous nature of blockchain events reliably.
• Act as a bridge between technologies, mentoring team members on how to effectively navigate a multi-language stack.

Required Skills

• Polyglot Proficiency: You must be comfortable working in a multi-language environment.
  • Rust: Strong proficiency for core backend logic and safety.
  • C++: Experience with systems programming, reading legacy code, or performance optimization.
  • Python: Proficiency for data processing, testing frameworks, or rapid scripting.
  • Node.js: Experience with the JS/TS ecosystem, particularly for Web3 SDKs and lightweight services.

• Backend Architecture: Deep understanding of API design (REST/gRPC), database modeling (SQL/NoSQL), and microservices.
• Distributed Systems: Understanding of eventual consistency, message queues, and handling asynchronous events.
• Intellectual Flexibility: The ability to pick the right tool for the job and adapt quickly to new libraries or protocols.
• English Proficiency: Upper-Intermediate (B2) or higher.

Preferred Skills

• Ethereum & EVM: Deep understanding of the Ethereum ecosystem, JSON-RPC standards, event logs, and ABI decoding.
• Major Chains: Experience integrating with other major networks (Solana, Near, Cosmos, or Bitcoin).
• Blockchain Nodes: Experience running or modifying nodes (e.g., Geth, Casper Node, Substrate).
• DevOps: Experience with Docker, Kubernetes, and CI/CD pipelines.
• Cryptography: Basic understanding of cryptographic primitives used in blockchain (hashing, signatures).

What you get

• The opportunity to work on complex, high-impact infrastructure projects where your versatility is a major asset.
• A transparent, friendly, and supportive team environment that values ownership and competence.
• A clear path for growth, where you are encouraged to experiment with and master new technologies.
• Competitive compensation based on your skills and experience.
• This is a long-term collaboration based on a 2-year B2B contract, reflecting our mutual investment in your growth and success with our team.