Senior Quality Assurance Engineer

Job Description — Senior QA Engineer

Location: London — 4 days a week in office, 1 day remote

Team: Platform

About Us

We build decision-making infrastructure for complex, real-world systems. Our platform combines edge-deployed sensors and intelligence with centralised algorithms, data pipelines, and graph-based analytics. We work primarily in global logistics, where we ingest data from sensors, emails, spreadsheets, and external databases to make predictions, detect problems, and support automated decisions across a distributed network of devices and agents.

The system includes edge devices with onboard sensors and compute, a central cloud-based analytics layer, and a graph-based data store and algorithmic engine that supports both machine learning and rules-based logic.

Job Description

We are hiring a Senior QA Engineer to own quality across the entire platform — from data pipelines and ML models to backend services and user-facing applications. This is not a manual testing role. We're looking for someone who can build automated test infrastructure, design performance benchmarks, validate ML outputs, and ensure data quality at every stage of the system.

You'll be the first dedicated QA hire in a team of 6 engineers. This means full ownership: you'll define our quality strategy, build the testing infrastructure from scratch, and be accountable for how we ship reliable software. The right person will be technically strong, comfortable writing code, and able to work independently across a complex system that spans edge devices, streaming pipelines, graph-based analytics, and web applications.

Key Responsibilities

• Design and implement automated testing strategies across the full stack
• Build and maintain test frameworks for backend services, APIs, and frontend applications
• Develop performance and load testing infrastructure to validate system behaviour at scale
• Create benchmarking frameworks for ML models, including accuracy, latency, and regression testing
• Implement data quality checks and validation across pipelines and databases
• Work with engineers to integrate testing into CI/CD pipelines and development workflows
• Define quality metrics and monitoring to catch issues before they reach production
• Investigate and diagnose bugs across the system, from data ingestion to user interface
• Champion testing best practices and help the team build quality into every stage of development

Requirements

We don't expect candidates to meet every requirement — if you're strong in some areas and willing to learn in others, we'd still like to hear from you.

• Strong programming skills, ideally in Python (our primary language)
• Production experience building and maintaining automated test suites
• Experience with test frameworks (pytest, Playwright, Selenium, or similar)
• Hands-on experience with performance and load testing tools (Locust, k6, JMeter, or similar)
• Understanding of data quality concepts and experience validating data pipelines
• Familiarity with CI/CD systems and integrating tests into automated workflows
• Ability to work across the stack — comfortable testing APIs, databases, and user interfaces
• Strong debugging and root cause analysis skills
• Experience working in a fast-moving environment with full ownership and accountability
• Comfortable making decisions independently and driving initiatives without close oversight

Bonus

• Experience testing or benchmarking ML models and systems
• Familiarity with streaming systems (Kafka) and event-driven architectures
• Experience with observability tools (logging, metrics, tracing)
• Understanding of logistics, supply chain, or IoT systems
• Experience as the first or early QA hire, building quality processes from scratch