Senior QA Engineer – Backend, API & Distributed Systems

BNB Chain; Hong Kong; On-site; HKD 600,000 - 1,000,000; Full time

Job summary

Ceffu is seeking a QA engineer to design, implement, and maintain test strategies for backend services and distributed systems. You will own quality across the SDLC, develop automated test frameworks, validate APIs and data workflows, and collaborate with cross-functional teams to ensure reliability and performance in high-concurrency environments.

Candidates should have 5+ years of backend/API testing experience, strong fundamentals in testing methodologies, SQL and Redis, and familiarity with

Qualifications

• Bachelor's degree in Computer Science, Software Engineering, or a related field.
• 5+ years of QA or software testing experience, with strong backend and API testing experience.
• Solid understanding of software testing methodologies, test design, defect management, and software engineering best practices.
• Strong experience with API testing, including RESTful APIs, authentication, error handling, and boundary conditions.
• Hands-on experience with test automation frameworks and scripting languages such as Java or Python.
• Strong understanding of distributed systems, scalability, reliability, fault tolerance, idempotency, concurrency, data consistency, and high availability.
• Experience testing microservices architectures and asynchronous systems.
• Experience with relational databases (MySQL/PostgreSQL) and SQL-based data validation.
• Experience with Redis, Kafka, RabbitMQ, or similar message queues.
• Experience with Docker and Kubernetes, Git, CI/CD pipelines.
• Experience with performance/load testing tools (JMeter, Gatling, Locust).
• Strong analytical, debugging, and problem-solving skills.
• Basic proficiency in reading and writing English.

Responsibilities

• Design, develop, and maintain comprehensive test strategies, plans, and cases for backend services and distributed systems.
• Own quality assurance across the software development lifecycle including requirements, design, tests, 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 scripts for RESTful APIs and backend services.
• Build test scenarios for high-concurrency and distributed systems emphasizing data consistency and high availability.
• Test APIs, databases, message-driven workflows, and system integrations for stability and efficiency.
• Collaborate with cross-functional teams to identify quality risks and deliver high-quality solutions.
• Conduct reviews of code and design from a quality perspective and promote QA best practices.
• Monitor production systems, reproduce defects, and identify quality and reliability risks; improve testing efficiency through automation and CI/CD.
• Lead or contribute to AI-assisted testing capabilities and knowledge sharing.

Skills

API testing

Backend testing

Test automation

Distributed systems

SQL

Redis

CI/CD

Docker

Kubernetes

Java/Python

Education

Bachelor's degree in CS/SE

Tools

JMeter

Gatling

Locust

Prometheus

Grafana

OpenTelemetry

Git

Job description

Ceffu is seeking a QA engineer to design, implement, and maintain test strategies for backend services and distributed systems. You will own quality across the SDLC, develop automated test frameworks, validate APIs and data workflows, and collaborate with cross-functional teams to ensure reliability and performance in high-concurrency environments.

Candidates should have 5+ years of backend/API testing experience, strong fundamentals in testing methodologies, SQL and Redis, and familiarity with