Agentic AI is changing how software gets built — and at SIX, it will touch the work of more than thousand engineers. We're building a new team at the center of this shift, responsible for shaping how AI-driven software engineering works across the company. As part of this team, you will build the guardrails that make agentic development trustworthy at scale: the test automation, coverage enforcement, and independent review layers that let AI agents write and ship code without compromising quality.

What You Will Do

- build test automation as a platform capability, not a project. Agent-driven test generation and maintenance, coverage enforcement on changed lines, flaky-test detection and self-healing, mutation testing, and test-suite health (redundancy, gaps, execution time) across unit, integration, and end-to-end layers.
- build and operate the AI agent harness.

The sandboxed execution environment, tool/permission scoping, and CI/CD integration that lets agents propose, test, and merge code, instrumented with decision logs and action provenance so every agentic change is traceable and reproducible.

- own the independent review layer for AI-generated code and tests: correctness, coverage, and quality gates in CI/CD that verify what an agent produces using tooling the agent doesn't control, so speed never comes at the cost of test quality or code health.

- define and evolve the test strategy for an AI-driven SDLC. What gets tested where, how test data is generated and managed, and how test quality is measured (not just pass/fail, but whether the tests catch regressions).




- treat test automation and guardrails as a product, not a gate.

Instrument for adoption, false-positive rate, and developer trust, keeping the safe, well-tested path the fastest path.

What You Bring
- 6+ years in software engineering with deep, hands-on expertise in test automation. Ideally a software/platform engineer in test, with a track record of building tooling or developer infrastructure that other engineering teams adopted, not just writing test suites.

- hands-on familiarity with agentic AI architectures. Agent orchestration, tool-use/sandboxing, and harness design, not just conceptual awareness of "AI in the SDLC."
- deep knowledge of test methodology and code quality: test pyramids, coverage strategy, mutation testing, flaky-test remediation, and what makes a test suite trustworthy versus just green.

- platform-product mindset. You build reusable capabilities and pave roads for other engineers, and you measure and strive for adoption and impact across SIX's business units.
- working knowledge of governance and controls in a regulated or high-assurance setting.

Financial market infrastructure experience is a plus, but adjacent regulated-industry background is a plus. A pragmatic, collaborative bias toward quality and automation.

What We Offer
- Hybrid model up to 40% working from home

- 37,5 hours/week with versátil schedule and 29+2 holidays
- Daily meal allowance
- Additional Medical Insurance for employee and family
- Pension fund
- Access to technical and language learning platforms

- Free parking spots, charger spots and shuttle bus

📌 AI Engineer - Test Automation & Guardrails (Madrid)
🏢 BME | Bolsas y Mercados Españoles
📍 Madrid