Machine Learning Engineer II - AI

Adyen; Amsterdam; On-site; EUR 70,000 - 110,000; Full time

Job summary

Adyen is seeking a Software Engineer II AI/ML - Payments to lead production-grade AI initiatives within our GenAI team. You will own the full lifecycle from research to deployment, building agentic systems and LLM-powered tools at scale in a payments context.

You will collaborate with product and engineering teams to identify high-impact opportunities, design MVPs, and establish evaluation frameworks to ensure reliable, production-ready AI outcomes. Amsterdam-based, office-first environment.

Qualifications

• 3–6 years of hands-on AI/ML research or engineering with production systems.
• Strong expertise in language models, generative AI, and production-grade code.
• Experience with agentic or multi-agent systems and tool-use in production.

Responsibilities

• Discover and build AI prototypes (MVPs) with product and engineering teams.
• Own end-to-end development of bespoke AI tools at Adyen's scale.
• Define evaluation strategy for agentic systems and LLMs; design benchmarks.
• Provide AI expertise across the organization on retrieval and tool-use approaches.
• Raise the bar with reproducibility, documentation, and rigorous evaluation practices.

Skills

Python

Applied AI/ML

LLMs

Agentic systems

MLOps

Evaluation frameworks

Multi-agent systems

Memory management

Tools

PyTorch

TensorFlow

Job description

Software Engineer II AI/ML - Payments

Adyen provides payments, data, and financial products in a single solution for customers like Meta, Uber, H&M, and Microsoft - making us the financial technology platform of choice. At Adyen, everything we do is engineered for ambition.

Our Payment Solutions team is the engine behind this, processing billions of transactions while empowering businesses to create seamless payment experiences. As Adyen and our merchants scale globally, the complexity and volume of our operational knowledge are growing exponentially.

To position our Payments organization at the technological forefront, we are establishing a GenAI team focused on identifying high-impact use cases for automation through agentic capabilities. As a Machine Learning Engineer II - AI/ML, you will undertake some of the most technically demanding work in applied AI: designing agents that reason over complex, multi-step tasks, building the infrastructure to ensure production-grade reliability, and shaping how humans and AI collaborate at scale within a global payments company.

This is not a narrow research role. You will take full ownership of your work, from early research through deployed production systems, influence the team's technical direction, and act as a force multiplier for the broader AI organization, including contributing to custom model development for structured financial data, and working toward our longer-term ambition of defining how humans and AI collaborate at scale across the company.

What you’ll do:

• Discover and Build: You will be an explorer within Adyen, proactively engaging with product and engineering teams to uncover their most critical challenges. You won't wait for instructions; you'll find high-impact opportunities and rapidly design and build AI prototypes (MVPs) to demonstrate value.
• Develop Strategic AI Products: You will own the end-to-end development of bespoke AI tools that solve problems unique to Adyen's scale. Whether it's optimizing merchant experience, enhancing pricing models, or improving internal workflows, you will build intelligent solutions.
• Own Evaluation and Benchmarking: Define and lead the evaluation strategy for the agentic systems and LLMs your team builds and deploys. Design internal benchmarks grounded in real domain complexity, probing for genuine capabilities, edge cases, and failure modes that standard metrics miss. Build reusable evaluation infrastructure that is embedded in the development process, not bolted on after the fact.
• Provide AI Expertise Across the Organization: Serve as a technical resource for AI initiatives across Adyen - evaluating agentic frameworks, retrieval and search strategies, or agent tool-use approaches across partner teams. Surface connections across initiatives and help teams avoid duplicating work or converging on the wrong approach.
• Raise the Bar: Set engineering standards for the team and company. Provide mentorship through problem decomposition, research methodology, and code review. Champion reproducibility, documentation, and rigorous evaluation practices across the AI organization.

Who you are:

• You have 3-6 years of hands-on experience in applied AI/ML research or engineering, with a clear track record of shipping AI systems, including agentic or LLM-powered systems, in production environments.
• You have deep expertise in language models and Generative AI, with hands-on depth across several of: architecture, post-training (fine-tuning, RLHF), inference optimization, context engineering (RAG), and failure modes at scale.
• You have proven experience designing and operating agentic systems at scale, multi-agent orchestration, tool use, memory and context management, state handling for long-running workflows, and human-in-the-loop design. You understand what separates production agents from research prototypes.
• You are rigorous and systematic about evaluation. You have designed evaluation frameworks or internal benchmarks that go beyond standard metrics. You understand the failure modes of LLM-as-judge approaches and know how to measure what actually matters for a given system and use-case.
• You have a strong foundation in classical machine learning: supervised learning, ensemble methods, optimization, probabilistic modeling, and statistics. You reach for the appropriate tool for the problem.
• You write clean, well-structured, production-ready code, primarily Python, and you hold research code to an engineering standard.
• You have hands-on experience with at least one production-grade agentic framework.

Nice to Have (tell us about them!)

• Familiarity with financial data, payments, fraud detection, or risk systems.
• Track record of external visibility: publications, conference presentations, or open-source contributions.
• Experience with observability and evaluation tooling.
• Familiarity with MLOps and model deployment pipelines in large-scale environments.

Our Diversity, Equity and Inclusion commitments

Our unique approach is a product of our diverse perspectives. This diversity of backgrounds and cultures is essential in helping us maintain our momentum. Our business and technical challenges are unique, and we need as many different voices as possible to join us in solving them - voices like yours. No matter who you are or where you're from, we welcome you to be your true self at Adyen.

Studies show that women and members of underrepresented communities apply for jobs only if they meet 100% of the qualifications. Does this sound like you? If so, Adyen encourages you to reconsider and apply. We look forward to your application!

What's next?

Ensuring a smooth and enjoyable candidate experience is critical for us. We aim to get back to you regarding your application within 5 business days. Our interview process tends to take about 4 weeks to complete, but may fluctuate depending on the role. Learn more about our hiring process here . Don't be afraid to let us know if you need more flexibility.

This role is based out of our Amsterdam office. We are an office-first company and value in-person collaboration; we do not offer remote-only roles.

The way we work is guided by the eight principles of the Adyen Formula. Learn more here.

Our engineers are building the first financial technology platform that combines payments, data, and financial services. We're looking for more talented problem solvers to help us address a unique set of challenges.