We’re building a world-class team to redefine knowledge work with AI Zeno is a legal AI startup building a platform that helps lawyers research, review, and draft documents with real legal reasoning — not just text prediction. We’re developing technology that can:

• Search and retrieve statutes, case law, and commentary with high precision.
• Reason step-by-step, applying legal tests and weighing precedents.
• Explain every answer transparently, so lawyers can trace conclusions back to the exact sources.

Where most tools automate surface-level tasks, we’re focused on replicating the way lawyers actually think through legal problems, making depth and trust the foundation of everything we build.

You’re joining an early-stage startup that is already working with leading firms. Backed with €3M in seed funding, we’re now scaling a team of engineers and thinkers who want to solve real problems, drive innovation, and create lasting change in the legal sector.

About The Role As a Staff Data Engineer — Entity Resolution & Identity , you will build and own the core systems that power Zeno’s data and AI platform. Your work sits at the heart of the product: determining what is the same, what is different, what is a version, and how those decisions evolve over time.

This role is centered on hard engineering problems. You’ll work with large volumes of unstructured and semi-structured legal data from many sources, formats, jurisdictions, and time periods. You’ll design systems that can evolve without constant reprocessing, where every decision is explainable, reversible, and traceable.

You operate at senior-to-staff level and take ownership of long-lived, mission-critical infrastructure where correctness, performance, and maintainability matter deeply.

What You’re Working On What you’ll build

• A durable entity resolution framework
• Canonical entities with stable IDs that survive logic and data changes
• Identity graphs with merge/split semantics and full provenance
• Matching and consensus logic balancing precision, recall, and durability
• Incremental recomputation (no “reprocess the world” when logic improves)
• Reversible decisions: merge, split, revert, replay
• System-level data quality, validation, and observability

You’ll build systems that can reliably answer:

• Are these two records the same real-world legal entity?
• Is this a duplicate, a variant, a new version, or something else?
• How do we evolve matching logic without rebuilding everything?
• How do we make merges reversible and decisions explainable?

Constraints you’ll work under:

• Unstructured and semi-structured legal data
• Conflicting, incomplete, and shifting sources of truth
• Long-lived correctness requirements across jurisdictions

Who You Are

• Staff-level experience in data engineering, solving non-trivial identity, deduplication, or consistency problems
• Strong system design instincts and ownership mindset
• Experience building complex, long-lived production systems
• Strong programming skills (for example Python or similar)
• Hands-on work with unstructured or semi-structured data

You think naturally in terms of:

• Entity resolution, record linkage, and deduplication
• Blocking and candidate generation trade-offs
• Precision/recall calibration
• Survivorship and conflict resolution
• G
• raph connected components and merge cascades
• Versioning, provenance, and replayability

Nice to have

• Experience in legal, government, or other high-complexity document domains
• Experience building human-in-the-loop review systems

Why this role This is not a role focused on maintaining pipelines. You will design and build systems that do not yet exist as standard solutions in a domain where data identity, correctness, and evolution over time are exceptionally challenging.

The ride from startup to scale-up means things will break, and there won’t always be a playbook. You’ll wear multiple hats, ship fast, and learn faster. If you thrive on ownership, speed, and building from zero, you’ll love it here.

The ride from startup to scale-up Things will break, priorities will shift, and there won’t always be a playbook. You’ll wear multiple hats, ship fast, and learn faster. Some weeks will feel chaotic, some problems will feel bigger than your role. That’s the nature of the ride from startup to scale-up: if you need stability and structure, this won’t fit. But if you thrive on ownership, speed, and building from zero, you’ll love it here.

Why join us

• Be part of a product-driven team reinventing how legal professionals work.
• Join early and shape the foundation of a fast-growing, high-impact startup.
• Work in a place where hierarchy doesn’t matter — only the best ideas do.
• Collaborate with a top-tier team of engineers, researchers, and entrepreneurs.
• Competitive compensation, employee benefits and strong upside as we grow.
• An inspiring place to work in the heart of Rotterdam.

Shape the future of legal work with us.