CARLOS

Hey, I’m
Carlos.

Product Data Scientist / ML Engineer

I work on data science and machine learning at IKEA. Here’s a bit about what I do, what I’ve worked on before, and what I like outside of work.

See what I’ve worked on 2019 — PRESENT
WHERE I’VE STUDIED & WORKED
Maastricht UniversityDHL ExpressASMLIKEA
  1. IKEA

    Global B2B · Madrid

    Product Data Scientist / ML Engineer

    I like to think of myself as a Product Data Scientist / ML Engineer. My work covers most of the process: figuring out what we need to solve, building the solution, taking care of the MLOps and data engineering behind it, and checking whether it actually helps.

    There’s also a lot of talking to people across IKEA: understanding what different teams need, what they’ve already tried and how our work could help.

    Recommendations

    On the B2B website, we wanted to get better at recommending products that customers would actually be interested in. I worked on improving the recommender’s predictions, with the aim of increasing click-through and conversion rates.

    Measuring impact

    Then there’s the question of how to tell whether a change actually helped. I worked on designing A/B tests for that. For projects that had already happened, I used causal inference and synthetic control groups to estimate their impact. That helps us decide what’s worth investing more time in.

    Room furnishing

    Another project has been working out how to furnish a room: which pieces to choose and where to put them. The placement part is a particularly important problem for IKEA, because there are so many products you could build around it.

    This involved a lot of research and talking to different teams, including AI Lab in Amsterdam.

    In earlier work, we tried approaches along the lines of MiDiffusion and PolyLayout. These give an idea of the kind of things we were exploring.

    The field has moved on quite a bit since then. These days I’m building an agentic system that does exactly that: you give it a prompt and it gives you back a furnished room — a bit like ChatGPT, but instead of a picture, the answer is a 3D room where you can move things around.

    TECH STACK
    • GenAI
    • GCP
    • Terraform
    • Git
    • Python
    • LangGraph
    • Google ADK
    • Langfuse
    • MLflow
    • Docker
    • Recommendation systems
    • Causal inference
    • AI agents
    • Cross-team collaboration
  2. ASML

    Overlay & Control · Software · Veldhoven

    Research Intern

    Predicting how chip layers will line up.

    Chips are built in layers, and those layers need to line up very precisely. If the displacement is too large, the part may have to be discarded. My work was about predicting that displacement and how uncertain the prediction was.

    I used time-series models and statistical methods to predict overlay, and conformal prediction to quantify the uncertainty. The idea was to help the team anticipate alignment problems and know how much confidence to put in a prediction.

    TECH STACK
    • Python
    • Time series
    • Statistics
    • Conformal prediction
    • Time series
    • Statistics
    • Conformal prediction
  3. DHL Express

    Global Data & AI · Maastricht

    Data Science · Student contract

    Forecasting how many packages will arrive.

    DHL Express needs to reserve airport capacity before the packages arrive. If more arrive than expected, extra space costs more. If fewer arrive, the reserved space goes unused.

    I worked on predicting those volumes using graph neural networks, attention mechanisms and a new architecture we developed for the problem. The architecture was a variant of an augmented message-passing approach, similar in spirit to the ideas discussed in the paper below. Better forecasts would help DHL reserve the right amount of space and avoid those extra costs.

    Related reading: Message passing all the way up

    TECH STACK
    • PyTorch
    • Airflow
    • Git
    • GCP
    • Graph neural networks
    • Attention
    • Demand forecasting
  4. Maastricht University

    Data Science & Artificial Intelligence

    Master’s degree

    My master’s at Maastricht.

    I stayed at Maastricht for my master’s and graduated cum laude. Alongside my studies, I worked at DHL Express and later did my research internship at ASML.

    • Graduated cum laude
  5. DHL Express

    Global Data & AI · Maastricht

    Data Science · Student contract

    Planning the aircraft schedule.

    DHL Express has its own aircraft to move urgent shipments around the world. Planning their schedules means coordinating the whole network while accounting for the constraints of the operation.

    I worked on a strategic scheduling problem that hadn’t been solved internally. It took a lot of research and conversations with people across the company to understand the problem and work out how to model it in a way that could scale to such a large network, with so many variables. I used a branch-and-price approach to break the problem into manageable pieces. The aim was to help planners coordinate the fleet more effectively.

    Related reading: Branch and price

    TECH STACK
    • Java
    • Git
    • CPLEX
    • Operations research
    • Optimisation
    • Air network planning
  6. Maastricht University

    Advanced Computing Sciences

    Bachelor’s degree · Data Science & AI

    Studying data science and AI.

    The degree is taught by Maastricht’s Department of Advanced Computing Sciences, which also runs the Computer Science programme. Ours is more maths-heavy, combining applied mathematics, computer science, machine learning and operations research.

    I graduated cum laude and with honours.

    BACHELOR’S THESIS

    A Branch and Price Approach for the Aviation Acyclic Problem

    9/10 · Nominated for best thesis of the year
    • Cum laude
    • Honours
    • Thesis: 9/10
    • Best thesis nomination
  7. 2019 · Started at Maastricht

02 MY APPROACH

How I usually
work.

01 / START WITH THE PAIN

Understand what needs fixing

I try to understand the pain first: what is getting in the way, who feels it and what would make a real difference. Product and research move at different speeds, but both need a clear understanding of the problem.

02 / WORK WITH AUTONOMY

Turn an abstract problem into something concrete

I like having the autonomy to explore and develop things myself: trying new ideas and turning an abstract question into a solution that can be tested.

03 / MEASURE THE VALUE

Be rigorous about what works

I like to measure whether something actually helps. I define useful metrics, run experiments and use the results to learn and create value. The rhythm may differ between product and research, but I bring the same care and rigour to both.

03 OUTSIDE OF WORK

Hey! I like
other stuff too.

Outside of work, I like reading, I’m learning to play chess, and I’m into football, basketball and tennis.

BOOKS

Reading

I really enjoy literature, although I haven’t been reading as much of it lately. Some authors I like are Philip Roth, Paul Auster and Vladimir Nabokov. You can see what I’ve been reading on Goodreads.

RothAusterNabokov
CHESS

Learning to play

I’ve just started taking chess lessons. Two classes so far, so I’m very much a beginner.

SPORTS

Sevilla FC,
basketball & tennis

I’m a Sevilla FC fan. I also play basketball — power forward — and tennis, although my one-handed backhand still needs some work.

FOOTBALL + BASKETBALL + TENNIS