QA Engineer; Typescript, Blockchain; OP; auto

We are hiring in Europe! , a US-based outsourced software development company, we're looking for contractors to join our global team of IT professionals helping tech companies scale their business through software engineering expertise. Operating as a remote-first company, our experts work across 55+ countries on five continents, giving us the flexibility and skillset to deliver high-quality engineering for projects of any size or complexity.

We invite a Senior QA Engineer to join our team and help evolve a large-scale blockchain-based platform for private markets. In this role, you’ll own end-to-end quality assurance, combining hands‑on manual testing with building and expanding test automation across backend services, distributed systems, and blockchain integrations. You’ll help establish testing approaches and automation practices from the ground up, working closely with engineering teams and business stakeholders to ensure reliable, high-quality releases.

• In this role, you'll lead testing activities across blockchain-based applications, from requirements analysis and manual validation to test automation and release support.
• Review business requirements and technical documentation to understand system functionality and identify testing needs.
• Manually test new features and existing functionality to understand system behavior and guide test automation efforts.
• Define and improve QA strategies, test plans, and quality gates.
• Establish testing ownership and coordinate responsibilities between QA and engineering teams.
• Work closely with engineering and product teams to define test coverage and acceptance criteria.
• Build and maintain automated test suites, frameworks, and test harnesses, focusing on backend, integration, and contract testing.
• Test blockchain integrations, smart contracts, REST APIs, JSON-RPC endpoints, MCP servers, and other blockchain-specific functionality.
• Integrate and monitor automated tests within CI/CD pipelines and quality gates.
• Investigate and troubleshoot issues across distributed systems and blockchain integrations.
• Adjust testing priorities and approaches as project needs evolve.
• Maintain test documentation, report quality risks, and communicate testing progress and blockers.
• Help expand automation coverage and improve QA practices across multiple projects.

• Hands-on experience testing blockchain systems, smart contracts, and transaction flows.
• Experience with Go for test automation.
• EVM testing experience using Foundry, Hardhat, or similar frameworks.
• Ability to read and understand Solidity or Rust code for smart contract validation.
• Experience with Layer 2 solutions and blockchain protocol testing.
• Experience testing asynchronous messaging systems (AWS SNS/SQS, Azure Service Bus).
• Experience with Kubernetes.
• Experience with observability-driven testing.
• Experience testing MCP servers.
• Experience with performance and load testing.

• Work on an innovative blockchain platform designed to bring trust and transparency to private markets.
• Deepen your expertise in blockchain systems, distributed architectures, and complex integrations.
• Drive the development of test automation frameworks and help shape quality practices across multiple projects.
• Is that you?
• 5+ years in QA/SDET roles, covering both manual and automated testing across the full SDLC.
• Strong experience with backend and non-UI test automation.
• Hands-on experience developing, maintaining, and debugging automated tests.
• Strong programming skills for test automation, preferably with Type Script/Node.js.
• Ability to define QA strategies, test plans, and quality gates from the ground up.
• Understanding of blockchain fundamentals, including wallets, transactions, and blockchain types.
• Experience testing REST…