Data Engineer

About Cala AI

From the creators of Vilynx - a Barcelona AI startup acquired by Apple - comes Cala AI: a bold new venture redefining how information is verified and represented at massive scale. Based in Barcelona's vibrant tech hub near Passeig de Gràcia, Cala AI is building innovative AI systems focused on trust, accuracy, and impactful technology that challenges industry norms.

Recently, Cala AI was named by Creandum to their #EuroSeed50 list - highlighting the most promising early-stage startups in Europe - an honor that reflects the strong belief in our mission and team. We are a small, ambitious group dedicated to building real solutions with grit, heart, and a culture of authenticity.

We are now growing our engineering team with an experienced Data Engineer who enjoys working across boundaries - data, backend, infrastructure, and applied AI.

About the role 💡

We're looking for an experienced data engineer with depth.

You'll come from a Data Engineering background - big data pipelines, storage systems, processing frameworks - but what matters most is your motivation to build across layers and solve complex problems end-to-end. Data is your anchor, but this is a high-impact engineering position for someone who enjoys working with multiple parts of the system rather than in a narrow specialization.

You'll architect, build, and scale the data systems that power large-scale AI-driven information verification and representation, engaging with emerging information representation systems like embeddings, Knowledge Graphs, and search engines to help shape the future of AI-driven data.

What you'll do 🛠️

Design and maintain scalable, high-throughput data pipelines and ETLs (batch and streaming)

Architect data storage and retrieval systems using SQL and NoSQL technologies (Cassandra, graph databases) for efficient processing

Collaborate closely with the team on system design and data modeling

Work with cloud infrastructure on AWS and containerized environments (Kubernetes)

Integrate and experiment with ML-based data representation techniques and emerging AI engineering tooling

Contribute to a culture of clean, pragmatic, high-quality engineering

Things we value 🔎

Strong background in:

Data Engineering (big data pipelines, storage systems, processing frameworks)

Technical stack we commonly work with:

Big data pipelines (Spark, Hadoop, Kafka or equivalent)

Python or Scala (Java welcome)

AWS

Kubernetes

SQL and NoSQL databases (Cassandra a plus)

Search and graph databases (Elasticsearch, Neo4j) are a nice to have

DevOps practices

Profile:

4+ years of hands-on data engineering experience, with real depth - you've gone deep, not wide and shallow

Able to reason about and justify your technical decisions: pros, cons, why A over B

Builders at heart: hackathons, side projects, open-source contributions, active GitHub are all highly appreciated

Curious about how things work end-to-end, including the parts adjacent to your own - infrastructure, backend, the systems your data feeds

Curious about the AI ecosystem and modern developer tooling

Comfortable in a fast-moving startup environment

C1+ level in either English or Spanish (fluency in either is acceptable)

Diversity & Inclusion 🌍

We are intentionally building a diverse team. We strongly encourage applications from women, underrepresented groups in tech, and individuals from non-traditional or less represented backgrounds. Diverse perspectives are critical to building responsible AI systems.

If you're excited about the role but don't meet every requirement, we'd still love to hear from you.

Compensation & Work Model 💼

Competitive salary

Stock options

Hybrid model: 3 days per week onsite

New office on Gran Via (Barcelona), with a full dedicated space for Cala AI

Flexible benefits covering transport, meals, and health insurance

Why Cala AI? ✨

Work alongside founders with a proven track record in AI startups

Build foundational AI systems with an "AI for good" focus

High ownership, high autonomy, real technical challenges

Join at an early stage and help shape both technology and culture

A supportive, inclusive, and horizontal team environment

Hiring Process – Conversation-Based (No Coding Tests) 🤝

Initial chat with team member focused on experience and projects

System design interview with CTO (onsite preferred)

Cultural fit conversation with CEO

Offer