Senior QA Engineer

About Ceffu

Ceffu is a leading institutional-grade digital asset custody platform, offering secure, compliant, and scalable solutions for enterprises, hedge funds, and financial institutions. 

Our mission is to provide cutting-edge security and infrastructure to support the seamless integration of blockchain technology into institutional finance.

Job Responsibilities

• Design, develop, and maintain comprehensive test strategies, test plans, and test cases for backend services and distributed systems.

• Take ownership of quality assurance throughout the software development lifecycle, including requirement analysis, test design, implementation, testing, deployment, and production support.

• Design and execute functional, integration, regression, system, and end-to-end testing for backend services and business workflows.

• Develop and maintain automated testing frameworks and test scripts for RESTful APIs and backend services.

• Build comprehensive test scenarios for high-concurrency and distributed systems, with a focus on data consistency, reliability, fault tolerance, idempotency, and high availability.

• Test and validate APIs, database models, message-driven workflows, and system integrations to ensure stability, correctness, and efficiency.

• Collaborate closely with cross-functional teams to identify quality risks and deliver high-quality solutions.

• Conduct code and technical design reviews from a quality perspective, contribute to testing standards, and drive QA best practices across the team.

• Monitor production systems, troubleshoot incidents, reproduce defects, and proactively identify quality, performance, and reliability risks.

• Continuously improve testing efficiency by enhancing test automation, CI/CD integration, test coverage, observability, and quality processes.

• Lead or contribute to the development and continuous improvement of the AI engineering capabilities, tools, and infrastructure.

• Stay current with emerging testing technologies and share testing knowledge and best practices with the team.

Skills & Experience Required

• Bachelor's degree in Computer Science, Software Engineering, or a related field.

• 5+ years of QA or software testing experience, with strong experience in backend and API testing.

• Solid understanding of software testing methodologies, test design, defect management, and software engineering best practices.

• Strong experience with API testing, including RESTful APIs, request/response validation, authentication, authorization, error handling, and boundary conditions.

• Hands-on experience with test automation frameworks and scripting/programming languages such as Java, Python, or similar.

• Strong understanding of distributed systems and testing concepts, including scalability, reliability, fault tolerance, idempotency, concurrency, data consistency, and high availability.

• Experience testing microservices architectures and asynchronous systems.

• Experience with relational databases such as MySQL or PostgreSQL, including SQL-based data validation and data integrity testing.

• Experience with caching technologies such as Redis.

• Familiarity with message queues such as Kafka, RabbitMQ, or RocketMQ, including testing asynchronous and event-driven workflows.

• Experience with containerization and deployment technologies such as Docker and Kubernetes.

• Familiarity with Git, CI/CD pipelines, and automated testing practices.

• Experience with performance and load testing tools such as JMeter, Gatling, Locust, or similar tools.

• Strong analytical, debugging, and problem-solving skills.

• Basic proficiency in reading and writing English.

Preferred Qualifications

• Experience testing or developing Web3, digital wallet, digital asset custody, cryptocurrency exchange, payment, or financial transaction systems.

• Understanding of blockchain fundamentals, including public/private key cryptography, wallet architecture, blockchain transactions, and digital assets.

• Experience testing or integrating blockchain infrastructure, blockchain nodes, smart contracts, Web3 technologies, or crypto-related products.

• Experience testing high-throughput, low-latency backend systems.

• Familiarity with observability and monitoring tools such as Prometheus, Grafana, ELK, or OpenTelemetry.

• Experience with security testing, financial transaction testing, data consistency, and transaction integrity.

• Experience applying AI technologies to improve test automation, test case generation, defect analysis, or engineering productivity is a plus.