Raw data in. Clean data out.

Hi, I'm Jasper Jansen, a freelance data engineer. I build the data warehouses, pipelines and MLOps infrastructure that turn scattered source data into numbers your team can rely on. And I help that team accelerate: juniors into seniors, strategy into working solutions, and the bar a little higher every sprint.

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  • 10 YearsExperience In Data
  • Social Data NerdHelping Others Accelerate
  • Cloud-AgnosticSQL · Python · Git · CI/CD
  • MScMedical Engineering, TU/e

How I work

AI writes more of the code every month. What makes a data team good is still people: how fast they learn, how well they turn business questions into solutions, and how high they set the bar. That's where I make the biggest difference.

Colleagues describe me as always willing to help, and as someone who somehow always finds a creative way to turn an issue into a solution. Some just call me “LLM Jasper”.

  • Growing people

    I turn graduates into juniors, and juniors into seniors.

    • Founded Dept's data engineering team and grew it to 12 people across several countries.
    • Led several traineeship cohorts, taking university graduates to junior engineers.
    • Weekly 1:1s and half-year learning plans, so growth is planned, not accidental.
    • Data lectures where I share new things and others present their own, plus talks at events.

  • From strategy to solution

    I translate a business question into a technical plan that answers it.

    • Define KPIs and a reporting strategy before anyone builds a dashboard.
    • Combine GA4 with campaign performance data into one view of what marketing spend delivers.
    • Untangle knotty technical issues into clear, solvable steps.

  • Raising the bar

    I challenge teams to step up their game, and give them the tools to do it.

    • Introduced version control with Git, and dbt for tested, documented models.
    • Taught Python and AI skills, so teams build faster with today's tools.
    • Coach a problem-solving way of thinking: understand the problem first, then build.

What I do

Hands-on engineering on any platform, and the coaching that makes a team faster.

  • Data warehousing & modelling

    Data models in dbt that analysts can trust: tested, documented and version-controlled, on BigQuery, Snowflake or Redshift.

    • dbt
    • SQL
    • BigQuery
    • Snowflake

  • Pipelines & orchestration

    ELT pipelines in Airflow that run on schedule and fail loudly, packaged in containers and shipped through CI/CD.

    • Airflow
    • Python
    • Docker
    • CI/CD

  • Platform migrations

    Moving a data platform without breaking the reports that depend on it, such as Randstad's move from BigQuery to Snowflake.

    • BigQuery
    • Snowflake
    • Airflow
    • dbt

  • MLOps

    The infrastructure to train, deploy and run machine learning models in production, as built for Rituals and Otrium.

    • Python
    • Google Cloud
    • AWS
    • MLOps

  • Marketing data & KPIs

    GA4 combined with campaign performance data, KPIs everyone defines the same way, and a reporting strategy marketing can actually steer on.

    • GA4
    • Marketing Tech
    • BigQuery
    • dbt

  • Team acceleration & coaching

    As lead engineer or coach: 1:1s and learning plans, traineeships for graduates, knowledge sessions, and new ways of working like Git, dbt and AI-assisted development.

    • Mentoring
    • Traineeships
    • Knowledge sharing
    • AI skills

From raw to clean

Two examples from everyday work: stitching web and app data into one customer, and turning inconsistent UTM tags into campaign results you can steer on.

Animated example of raw data being cleaned. Web cookies and an app device are linked to one user, and inconsistent UTM tags are mapped to campaigns with sessions, conversions, cost and ROAS.

Profile

Cloud-agnostic data engineer with ten years of experience, from web analytics to complete data platforms. I build data warehouses, pipelines and MLOps infrastructure on principles that carry across platforms (dbt, Airflow, containers, CI/CD), on any cloud for clients including Rituals, Randstad, NN Investment Partners and Otrium. Just as important: I make teams faster. I founded Dept's data engineering team (12 people), ran traineeships and coach juniors to senior level. Background in medical engineering (MSc, TU/e).

Prefer a document?

CV in EnglishCV in Dutch

Experience

  • Nov 2021 – present

    5 yrs 1 mo

    This Is Data

    Own company · freelance data engineer

    • Data Engineer · Rituals

      Aug 2025 – present

      • Design and maintain the data warehouse models (BigQuery + dbt) for the Digital department.
      • Develop and run the data engineering architecture on Google Cloud, including pipelines and infrastructure.
      • Handle MLOps for developing and deploying AI models.
      • Guide and mentor team members and lead the technical execution of projects.
      • BigQuery
      • dbt
      • Google Cloud
      • Python
      • MLOps

    • Data Engineer · Dept · two largest data clients

      Oct 2023 – Jul 2025, Rotterdam

      • Randstad: migrated the data platform from BigQuery to Snowflake, with Airflow and dbt for orchestration.
      • Rituals: built the architecture for machine learning models and maintained the marketing BigQuery data warehouse.
      • Snowflake
      • BigQuery
      • Airflow
      • dbt
      • Python

    • Data Engineer · NN Investment Partners

      Sep 2022 – Sep 2023, Den Haag

      • Risk Management Tooling team, responsible for reporting all risk KPIs for every fund managed by NNIP.
      • Built pipelines and data models with Airflow, dbt and ECS on AWS.
      • AWS
      • Airflow
      • dbt
      • ECS

    • Data Engineer · Otrium

      Nov 2021 – Aug 2022

      • Set up a machine learning pipeline in AWS for the pricing team's smart pricing model.
      • Built ELT pipelines for competitor pricing data in Airflow with custom operators; BI data models in Redshift.
      • AWS
      • Airflow
      • Redshift
      • Python

  • Oct 2016 – Nov 2021

    5 yrs 2 mo

    Dept

    Digital agency · Rotterdam

    • Lead Data Engineer

      Dec 2020 – Nov 2021

      • Founded the data engineering team and grew it to 12 people in several countries.
      • Airflow
      • BigQuery
      • dbt
      • Apache Beam
      • Docker
      • CI/CD

    • Data Engineer

      Apr 2018 – Nov 2020

      • Helped clients set up their online data as the foundation for better decisions.
      • Led traineeship cohorts (graduate → junior) and coached juniors to senior level.
      • BigQuery
      • Cloud Functions
      • Dataflow
      • GA360
      • Tag Manager
      • Tealium

    • Digital Analytics Consultant · Expand Online (now Dept)

      Oct 2016 – Mar 2018

      • Moved from medical data to web analytics; analysed large datasets.

  • Oct 2015 – Sep 2016

    1 yr

    Reinier de Graaf

    Hospital · Delft

    • Medical technology traineeship

      Oct 2015 – Sep 2016

      • Assured quality of medical equipment: maintenance plans, training and procurement.

Skills

Data engineering

  • SQL
  • Python
  • dbt
  • Airflow
  • Apache Beam
  • Data modelling
  • MLOps

Platform-independent

  • Data Warehousing
  • Docker
  • CI/CD
  • ELT
  • Platform migration
  • Git

Cloud platforms

  • Google Cloud (BigQuery, Cloud Run, Airflow)
  • AWS (Redshift, ECS)

Leadership & coaching

  • Mentoring
  • Team building
  • Traineeships
  • Knowledge sharing

AI & agents

  • Claude Code
  • Gemini CLI
  • AI agents
  • Skill development

Digital analytics

  • GA4 / GA360
  • Google Tag Manager
  • Marketing Tech
  • KPI definition

Education

MSc Medical Engineering

Technische Universiteit Eindhoven, 2012–2015

Graduation project at Máxima Medical Centre; research internship at UC San Diego (patient-specific heart modelling).

BSc Biomedical Engineering

Technische Universiteit Eindhoven, 2008–2012

Erasmus minor in Biomedical Engineering, Queen Mary University of London.

Languages

  • DutchNative
  • EnglishFluent

Other activities

Volunteer firefighter

Veiligheidsregio Midden- en West-Brabant · Steenbergen

Jul 2025 – present

Publications (2)
  • Test–retest reliability of skeletal muscle oxygenation measurements during submaximal cycling exercise in patients with chronic heart failure
  • Characterization of exercise limitations by evaluating individual cardiac output patterns: a prospective cohort study in patients with chronic heart failure

A data problem, or a team to level up? Let's talk.

Tell me about your data, your team and what you're trying to achieve. I can join as an engineer, a lead or a coach. I'll get back to you within two working days.

Or reach me directly