Principal Data Scientist

Permanent employee, Full-time · Oficina Plaza España, Híbrido

About this role

Your mission?

Turn our rich operational and product telemetry into trustworthy, timely, secure, and business-ready data. Build the semantic layer and pipelines that power GTM, Product, Operations, and Partner Success—so decisions are faster, experiments are rigorous, and growth is compounding.


The role


What are we looking for?
We’re hiring a Principal Data Scientist / Developer—part architect, part builder, part strategist—to own our end-to-end data foundation and accelerate impact from insights to shipped improvements.

You’ll partner with Product and Engineering leads to design the next-gen data platform (batch and streaming), define metrics and contracts, and ship models (analytics, ML, and LLM-assisted) that lift activation, expansion, and reliability.

Reporting to the COO, you’ll work hands-on while coaching others, translating business questions into robust, production-grade data products. This role is based in Madrid, Spain, with a hybrid work model.

This isn’t about dashboards alone—it’s about building the engines that move the business.


What you’ll own and drive

  • End-to-end data infrastructure: From ingestion to orchestration to serving (batch/stream), optimizing cost, reliability, and speed.

  • Data quality, integrity, and availability: CI/CD for data, contracts, tests, and observability as first-class citizens.

  • Pipelines & processes: Design/optimize ingestion, transformation, and analysis workflows for structured and unstructured data.

  • Insights to action: Partner with GTM, Product, Operations, and Partner Success to prioritize questions, run experiments, and land changes.

  • Models & semantics: Own core metrics, semantic layers, reporting models, and feature stores aligned to the partner funnel (SQL→MQL→SQL→ARR).

  • Governance & collaboration: Lineage, catalog, permissions, and clear documentation so teams can self-serve safely and confidently.

Day-to-day tasks

  • Design/optimize pipelines (ingestion, transformation, orchestration).

  • Develop and maintain analytical and ML/LLM models (structured/unstructured; stats/experimentation).

  • Implement/improve dashboards (Dash/Plotly, Power BI, Tableau, Looker).

  • Analyze trends/patterns to improve processes, product, and the partner funnel.

  • Data modeling (dimensional, lakehouse, feature stores).

  • Data quality & observability (detect/fix inconsistencies).

  • Coordinate accessibility & usability (catalog, lineage, permissions).

  • Automate extraction/transformations, data testing, and deployment.

  • Document best practices, standards, and methodologies.


Tooling you’ll use
Linux, bash, Git, Containerization; SQL/NoSQL; Flask/FastAPI for APIs; Data stack: Pandas, scikit-learn, Polars, DuckDB; DL stack: PyTorch, HuggingFace, TensorFlow; Dash/Plotly/Power BI; Slack; Microsoft O365; Jira; Confluence; Cloud platforms & data services.


What will make us fall in love with you as a candidate?

It will be a perfect match if…

  • You are proactive. You spot data gaps early and propose scalable solutions without waiting for direction.

  • You prioritize clarity over clutter. You define crisp metrics and contracts, and make complex systems understandable.

  • You rock in strategic storytelling. You turn analysis into compelling narratives that move execs and engineers to act.

  • You are brave & creative. You experiment fast, embrace feedback, and solve problems others deem “too technical” or “too messy.”

  • You simplify the complex. You design data models and APIs that make cloud workflows intuitive for partners and internal teams.

  • Ownership. You can lead the full data lifecycle—from ingestion to models to serving and observability—hands-on and end-to-end.

  • You love being the bridge between tech and business. You translate questions into analysis, and insights into shipped changes.

  • For you, user and business impact go first. You champion data integrity and responsible AI to improve real outcomes.

  • Trust. You give and receive feedback thoughtfully, with the intent to build, and you lead with transparency.


Requirements that are important for us

Please, only apply if you match these.

  • A principal level: 8+ years across Data Science/Analytics/Engineering (including leading initiatives), with shipped data products and measurable business impact.

  • Mastery of data tooling: Python (preferred) and/or R; SQL & NoSQL; visualization (Power BI, Tableau, Looker, Dash/Plotly); ML/LLM/stats; cloud data services. You use AI responsibly to speed up quality work.

  • English skills: Intermediate level required — Level B1 minimum (B2+ is a plus) to collaborate with international teams.


Data

  • SQL & NoSQL excellence: Schema design, performance tuning, partitioning, indexing.

  • ETL/ELT & orchestration: Reliable pipelines (batch/stream) with monitoring, alerting, and recovery.

  • Modeling: Dimensional modeling, lakehouse patterns, and feature stores that serve analytics and ML.

  • ML/LLM & experimentation: From baseline models to rigorous A/B tests and causal inference on structured/unstructured data.

  • Visualization: Power BI, Tableau, Looker, and Dash/Plotly for decision-ready views.

  • Observability & governance: Data tests, lineage, contracts, catalogs, and CI/CD for data.

  • Quality by design: Freshness, completeness, accuracy, and SLAs as non-negotiables.


Engineering

  • System design & architecture: Comfortable with monoliths, microservices, and event-driven patterns.

  • APIs & services: Build/consume services with Flask/FastAPI; productionize models and data apps.

  • Cloud & data services: Practical fluency with cloud storage/compute and managed data offerings.

  • Core stack: Python, Pandas, Polars, DuckDB, scikit-learn; DL with PyTorch/TensorFlow/HuggingFace.

  • DevX: Linux, bash, Git, containerization; automation, testing, and CI/CD for code and data.

  • Security-minded: Design with least privilege, encryption, and secure defaults.


Security & Compliance
The Data Analytics team ensures secure and responsible data use in line with ISO 27001, ENS, and HDS—protecting confidentiality, integrity, and availability.


We anonymize and encrypt where applicable, enforce access controls, uphold data quality, and ensure that analysis tools/platforms are compliant. You’ll work closely with our Security team to bake this into architecture and day-to-day operations.

About us

Ready to shake up the tech world? At Jotelulu, we’re on a mission to empower Technology Service Providers with our secure, all-in-one cloud platform. We unite automation, AI, and growth tools, giving our partners the freedom to scale fast, launch big ideas, and build their brand with confidence.
This is the perfect time to join us: the company is growing rapidly, the challenges are exciting, and each person has a real impact.

If you are passionate, ambitious and ready to help shape the future of cloud technology, we want to meet you. You will join a fun, fast-paced, collaborative, and agile team, helping us scale our platform to millions of users while building out Jotelulu’s own infrastructure and data centers with the latest technologies.


Life a Jotelulu
 
We’re passionate about technology, but we’re also a bit geeky—we love Star Wars, video games, 90s movies, and pop culture.
 We work hard and with passion, but we also have a great time together. At Jotelulu, you’ll find a balance between work and fun, where teammates often become friends, and boredom is rare—there’s always something new, unexpected, and memorable happening. 


Videos behind the scenes
 
Meet our team! 


This is how we roll at events!



  Our own event, the SUMMIT  

What we offer?
At Jotelulu, we’re building something big, and we want you to be part of it.
We don’t do red tape or endless layers of approval. Here, ideas move fast, and your opinion actually counts.

We believe in flexibility and balance, because work is part of life, not the other way around. Whether you’re at home, in the office, or anywhere in between, what matters most is the impact you make.

You’ll join a team that’s growing and learning together, where challenges are real, but so are the opportunities to stretch your skills and shape your career path. We’ll give you the tools, the trust, and the feedback to help you keep moving forward.

Our culture is inclusive, friendly, and refreshingly down-to-earth. No suits, no egos, just a bunch of people who enjoy what they do and respect each other’s individuality.

We also take care of the essentials: access to quality healthcare, a transparent feedback culture (including regular 1:1s and performance reviews), and open communication through company-wide updates.

We also take care of your well-being:
- Private health insurance with access to a top-tier medical network.
- A friendly, inclusive culture where everyone can be themselves.
- Casual dress code (yes, t-shirts and sneakers are perfectly fine).
- Team gatherings and informal events to celebrate milestones and recharge together.
- We would love to hear from you and have the opportunity to work together.

We’re excited to discover what you’ll bring to the team.

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