AI TEST ENGINEER

Reply, Inc.; Greater London; On-site; GBP 70,000 - 110,000; Full time

Job summary

Reply is seeking a mid/senior AI Testing & Engineering Specialist with strong Python expertise to build and evolve a next-generation testing framework for generative AI agents. You will work across AI engineering, data pipelines, and quality automation, shaping standards for AI system validation in production environments.

The role focuses on architecture design and hands-on development of evaluation pipelines, synthetic data generation, and observability layers to deliver robust quality

Qualifications

• 2–5+ years of experience in Software Engineering, Test Automation, AI Engineering, or Data Engineering.
• Strong proficiency in Python and data/AI libraries (Pandas, NumPy, PyTorch).
• Experience with test automation frameworks (PyTest, Playwright) and CI/CD pipelines.
• Familiarity with data pipelines, dataset design, or feature engineering is a strong plus.
• Experience with evaluation metrics for NLP/AI systems (BLEU, ROUGE, embedding-based metrics) preferred.

Responsibilities

• Design and develop Python-based frameworks for testing and evaluating AI agents and LLM-based systems
• Contribute to architecture design for evaluation pipelines, observability, and data‑driven testing systems
• Build and maintain tools for test data generation (including synthetic and adversarial datasets)
• Define and implement evaluation strategies and quality KPIs for AI behavior (accuracy, robustness, bias, consistency, hallucination rate, etc.)
• Integrate LLM evaluation tools, CI/CD pipelines, and external AI platforms
• Support continuous testing, benchmarking, and production monitoring of AI systems
• Collaborate with AI engineers, data engineers, and QA teams to improve system reliability and scalability

Skills

Python

AI Testing

Test Automation

Data Engineering

LLM / NLP

Tools

PyTest

Playwright

CI/CD

Pandas

NumPy

PyTorch

Job description

Requisition ID11321-Posted10/02/2026- Years of Experience (2) -Technology- Where (1) -Job

Reply specialises in designing and implementing solutions based on new communication channels and digital media. Structured as a network of highly specialised companies, Reply supports leading European industrial groups in sectors such as Telco & Media, Industry and Services, Banking and Insurance, and Public Administration, helping define and develop business models enabled by new paradigms such as AI, Cloud Computing, Digital Media, and the Internet of Things. Reply’s services include Consulting, System Integration, and Digital Services.

Role Overview:

We are looking for a mid/senior-level AI Testing & Engineering Specialist with strong Python expertise and solid experience in AI, Data Engineering, or Test Automation. The role is focused on building and evolving a next-generation testing framework for generative AI agents, including evaluation pipelines, synthetic data generation, observability layers, and quality metrics for LLM-based systems. You will work across AI engineering, data pipelines, and quality automation, contributing both to architecture design and hands‑on implementation of scalable testing and evaluation systems. This role is suited for someone who can operate independently, contribute to technical decisions, and help shape standards for AI system validation in production environments.

Responsibilities:

• Design and develop Python-based frameworks for testing and evaluating AI agents and LLM-based systems
• Contribute to architecture design for evaluation pipelines, observability, and data‑driven testing systems
• Build and maintain tools for test data generation (including synthetic and adversarial datasets)
• Define and implement evaluation strategies and quality KPIs for AI behavior (accuracy, robustness, bias, consistency, hallucination rate, etc.)
• Integrate LLM evaluation tools, CI/CD pipelines, and external AI platforms
• Support continuous testing, benchmarking, and production monitoring of AI systems
• Collaborate with AI engineers, data engineers, and QA teams to improve system reliability and scalability

About the candidate:

• 2–5+ years of experience in Software Engineering, Test Automation, AI Engineering, or Data Engineering

Strong proficiency in Python and data/AI libraries (e.g., pandas, numpy, PyTorch or similar)

Solid understanding of LLMs, NLP concepts, or generative AI systems

Experience with test automation frameworks (e.g., PyTest, Playwright) and CI/CD pipelines

Familiarity with data pipelines, dataset design, or feature engineering is a strong plus

Experience with evaluation metrics for NLP/AI systems (BLEU, ROUGE, embedding-based metrics, or custom scoring approaches)

Ability to design scalable systems and work autonomously on complex technical problems

Strong analytical mindset and interest in AI system quality, reliability, and governance

Reply is an Equal Opportunities Employer and committed to embracing diversity in the workplace. We provide equal employment opportunities to all employees and applicants for employment and prohibits discrimination and harassment of any type regardless of age, sexual orientation, gender, identity, pregnancy, religion, nationality, ethnic origin, disability, medical history, skin colour, marital status or parental status or any other characteristic protected by the Law.

Reply is committed to making sure that our selection methods are fair to everyone. To help you during the recruitment process, please let us know of any Reasonable Adjustments you may need.