QA Engineer

Efsora; London; On-site; GBP 50,000 - 70,000; Full time

Job summary

A leading software development company is seeking a QA Engineer to ensure the quality of AI-powered web applications. The ideal candidate has 5+ years of experience, strong skills in JavaScript and Python, and proficiency in automated testing. This role involves designing test frameworks, conducting performance tests, and collaborating with developers to maintain the quality of innovative systems.

Qualifications

• 5+ years of professional experience in Quality Assurance.
• Strong proficiency in JavaScript/TypeScript and Python.
• Experience with automated testing for web applications.

Responsibilities

• Design and maintain automated test frameworks.
• Develop tests for AI model integration.
• Lead the execution of quality tests across applications.

Skills

JavaScript/TypeScript

Python

Test automation

API Testing

Performance Testing

Problem-Solving

Communication

Tools

Cypress

Playwright

Jest

Pytest

PostgreSQL

Docker

Job description

Job Title: QA Engineer

Level: Mid

Location: Urla, Izmir

Type: On-site

About Efsora

We are a fast-growing software and AI development company that partners with innovative enterprises and scaleups to deliver large, cutting-edge R&D projects. Our teams work as extensions of our clients’ internal R&D, combining advanced technology expertise, AI-centric engineering, and agile development to build impactful solutions. We focus on augmenting our clients’ R&D capabilities, accelerating innovation, and managing technical risks from early-stage prototyping to full-scale deployment. As part of our team, you’ll work on exciting, high-stakes projects that shape the future of industries, collaborate with top-tier talent, and grow your skills at the frontier of AI and software development.

The Opportunity

We are seeking a highly skilled and proactive QA Engineer to join our engineering team. This is a critical role for an individual passionate about ensuring the highest quality in cutting-edge web applications that integrate real-time data processing, advanced AI-driven features, and robust backend services. As a key contributor, you will work hand-in-hand with our Full-Stack Developers, AI Developers, and Product Managers to design, implement, and maintain comprehensive automated test solutions that validate the integrity, performance, and reliability of our innovative systems. You will play a pivotal role in maintaining the high standards expected from our AI-powered products.

What You'll Do

• Test Strategy & Automation: Design, develop, and maintain robust, scalable, and efficient automated test frameworks and scripts for both front-end (UI) and back-end (API, microservices) components.
• AI/ML Feature Testing: Develop specialized tests to validate AI model integration, data pipelines feeding AI, inference accuracy, output quality, and edge case behavior of AI-driven features. This includes testing for data consistency, model drift, and intelligent user interactions.
• End-to-End Quality: Lead the development and execution of comprehensive functional, integration, regression, performance, and security tests across the entire application stack.
• CI/CD Integration: Integrate automated tests into our continuous integration and continuous deployment (CI/CD) pipelines to enable rapid feedback and maintain high code quality standards.Performance & Scalability Testing: Design and execute performance, load, and stress tests to identify bottlenecks and ensure applications can handle high traffic and data volumes.
• Security Testing: Collaborate with development to ensure robust security implementations by testing authentication (OAuth, SAMLv2, JWT), authorization (RBAC), and data privacy controls.
• Collaboration & Advocacy: Work closely with developers, participating in design reviews and code reviews, advocating for testability, and promoting a quality-first mindset throughout the development lifecycle.
• Problem-Solving & Debugging: Perform thorough root cause analysis of defects, collaborate with development teams to resolve issues, and ensure proper defect tracking and resolution.
• Innovation: Stay abreast of the latest advancements in QA methodologies, test automation tools, and AI testing strategies, bringing new ideas and best practices to the team.

What We're Looking For

• Experience: 5+ years of professional experience in Quality Assurance, with a strong focus on test automation for complex, distributed web applications.
• Programming Expertise: Strong proficiency in JavaScript/TypeScript and Python for developing and maintaining test automation frameworks.
• Test Automation Tools: Hands-on experience with modern UI test automation frameworks (e.g., Cypress, Playwright) and API testing frameworks (e.g., Jest, Pytest, SuperTest).
• API Testing: Solid experience designing and executing tests for RESTful/GraphQL APIs and microservices.
• Cloud & DevOps: Familiarity with cloud platforms (AWS, Azure, or GCP), Docker, and Kubernetes from a testing perspective, including deploying and managing test environments.
• Database Knowledge: Experience with validating data integrity and consistency across both SQL (e.g., PostgreSQL, MySQL) and NoSQL (e.g., MongoDB, Redis, Cassandra) databases.
• Performance Testing: Experience with performance testing tools (e.g., JMeter, k6) and analyzing performance bottlenecks.
• Security Testing Awareness: Understanding of common web security vulnerabilities and experience testing authentication and authorization mechanisms (OAuth, SAMLv2, JWT, RBAC).
• Version Control: Proficient with Git for source control and collaborative development.
• AI/ML Testing Acumen: Demonstrated understanding and practical experience in testing applications that incorporate AI/ML models, including approaches to validate model outputs, data quality, and responsible AI principles.
• Problem-Solving: Excellent analytical skills with a meticulous attention to detail, capable of identifying subtle bugs and complex system interactions.
• Communication: Strong verbal and written communication skills, with the ability to articulate complex technical issues clearly and collaborate effectively across cross-functional teams.
• AI-Assisted Testing: Familiarity with leveraging Generative AI tools (e.g., Claude Code, Cursor, Copilot) to assist in test case generation, test script optimization, or data synthesis.

Bonus Points If You Have

• Complex Test Data Management: Proven ability to strategize, design, and implement advanced test data generation, anonymization, and management solutions for large-scale and dynamic datasets.
• Security Testing Acumen: Hands-on experience with security testing tools and methodologies (e.g., SAST/DAST, fuzz testing, penetration testing concepts) to identify and validate vulnerabilities.
• MLOps Quality Assurance: Understanding of MLOps pipelines and how quality assurance processes, including model validation, bias detection, and continuous monitoring, integrate throughout the AI model lifecycle.
• Contributions to Open-Source: Contributions to open-source test automation projects, frameworks, or a strong GitHub profile showcasing technical prowess.
• Fast-Paced Environment Experience: Experience in a startup or fast-paced, high-tech environment, demonstrating strong adaptability and a proactive approach to quality.