[Hiring] Senior Data Engineer @Proton.ai

Role Description

We're hiring a Senior Data Engineer to own and grow our Data Layer — the unified foundation that every Proton product and our AI brain are built on. You'll own the pipelines and architecture end to end:

• The medallion-style layers (raw → refined → curated)
• Ingestion from a wide range of systems
• The serving the whole company depends on

We're investing heavily to make the Data Layer bigger and better, and this role is for someone who wants to do the hands-on building and shape where it goes next.

Two things make this role different from a standard data engineering opening:

• You're an AI-native operator, not a pipeline author.
• Every engineer at Proton uses Claude Code and other agentic tools as first-class collaborators.

You own the layer everything runs on. When the AI gives a wrong answer or a number doesn't match the source, the trail leads back to the data. You own correctness end to end — ingestion, modeling, reconciliation, and the contracts other teams depend on.

Location: Europe, remote. Meaningful daytime overlap with our Boston (EST) team required.

Qualifications

• 7+ years hands-on as a data engineer with real, demonstrable production ownership — pipelines and data models serving real users at scale.
• Strong fundamentals. You understand what your code and your queries are doing and why.
• Strong programming and SQL skills.
• Hands-on orchestration experience, building reliable ingestion/ELT pipelines against messy upstream sources.
• Experience with a cloud data warehouse and a major cloud platform.
• Experience ingesting from multiple source types: file-based, event/streaming, and API-based.
• Solid grasp of data-consistency failure modes — partial loads, late or out-of-order data, idempotency, backfills, schema drift.
• Daily, hands-on use of agentic dev tools (Claude Code, Cursor agent mode, Codex, or equivalent) to ship real work.
• Ownership and judgment. You take data systems from idea to production.
• Startup mindset and strong communication — pragmatic, fast, biased to ship.
• English at C1 or above.

Requirements

• Deep cloud data warehouse experience and modern transformation tooling.
• Streaming/event ingestion at scale.
• Medallion or lakehouse architecture experience on large, multi-source data.
• Experience integrating enterprise sources such as ERP (Epicor Eclipse, Prophet 21) or ecommerce systems, and reconciling messy transactional data.
• Building data systems that feed AI/ML or agentic products — serving/feature layers, retrieval, or data contracts for model inputs.
• Prior experience at an early-stage SaaS startup.