Software engineer in quantitative finance, distributed systems, HPC, and ML.

  1. The Python stack for machine learning

    Python runs machine learning not because the language is fast but because it is the control layer over a stack of compiled libraries that now share memory…

    pythonmachine-learning

  2. Boosting

    Boosting builds a strong model from many weak ones trained in sequence, each focusing on what the previous ones got wrong.

    ml basicsmachine-learningensembles

  3. Random forests

    A random forest is bagging with one extra rule: at every split, each tree may only choose from a random handful of the features.

    ml basicsmachine-learningensembles

  4. Portfolio optimisation

    Portfolio optimisation chooses how much to put in each asset so that, for the risk you accept, the expected return is as high as possible; it works because…

    finance statsstatisticsportfolio

  5. Bagging

    Bagging trains many copies of the same model, each on a slightly different random resample of the data, and averages their answers; the copies make different…

    ml basicsmachine-learningensembles

  6. Sharpe, Sortino and Information ratio

    A return on its own means little until you know the risk taken to get it; these three ratios divide extra return by risk, and they differ only in what they…

    finance statsstatisticsportfolio

  7. Bias and variance

    A model's error on new data comes from three places: bias (it is too simple to capture the real pattern), variance (it changes too much depending on which data…

    ml basicsmachine-learningoverfitting

  8. Covariance, correlation and portfolio variance

    Covariance and correlation measure whether two things tend to move together; in a portfolio, that one number decides how much of the risk cancels out, which is…

    finance statsstatisticsportfolio

  9. Decision trees

    A decision tree makes a prediction by asking a short series of yes/no questions about the input, like a flowchart an expert would draw; it learns which…

    ml basicsmachine-learningdecision-trees

  10. Mean and standard deviation

    The mean tells you where the middle of your data is, and the standard deviation tells you how far a typical value strays from that middle; in finance the first…

    finance statsstatisticsreturns

  11. Linear regression

    Linear regression draws the straight line that best fits your data, where "best" means the total of the squared misses is as small as possible; each number it…

    ml basicsmachine-learningregression

  12. Expected value

    Expected value is the average result you would get if you could repeat a risky situation many times: multiply each possible outcome by its probability and add…

    finance statsstatisticsprobability

  13. Regression vs classification

    Most machine learning answers one of two questions: "how much?" (regression, the answer is a number) or "which one?" (classification, the answer is a category).

    ml basicsmachine-learningvolatility

  14. Probability basics

    A probability is a number between 0 and 1 that says how often something happens in the long run.

    finance statsstatisticsprobability

  15. What is machine learning?

    Machine learning is teaching a computer by example instead of by instruction: you show it many past cases with the right answers, it works out the pattern on…

    ml basicsmachine-learningfraud

  16. Letting my homelab do things on its own

    A chat window only answers when I ask. I wanted my homelab to also do small jobs for me on its own, so I tried two AI agents, OpenClaw and Hermes Agent.

    agentshermes

  17. Switching to a smaller model

    I expected a new, smaller model to be slower on my homelab, and at first it was. Then I found one setting that more than doubled its speed.

    llmself-hosting

  18. Setting up my homelab

    I wanted my own private AI, running at home, where nothing I ask leaves the house.

    llmself-hosting