[DSRP Evidence](https://dsrpevidence.org/)

# Mental Model of the Week (#2): Sharpen your systems thinking with DSRP

## Details

**Authors** Calais, Pedro

**Year** 2026

**Publisher** Substack (pcalais.substack.com)

**Kind of work** blog

**Discipline** Computer Science & AI

**Secondary disciplines** Business & Management

**Kind of engagement** public

**Applied** false

[Read it](https://pcalais.substack.com/p/mental-model-of-the-week-2-sharpen)

## In authors' words

### What they set out to do (purpose)

To introduce DSRP to a readership of senior software engineers and engineering managers as a tool for problems that become more systemic as a career advances, and to show how the four patterns can be used to build a mental model of an unfamiliar technical concept.

### How they did it (methods)

A short newsletter essay in four moves: an argument that senior technical problems are systemic rather than local, a definition of each of the four patterns, an account of where the author first encountered DSRP, and one worked example applying the four patterns to Principal Component Analysis.

### What they found (results)

Calais argues that the four patterns are fundamental to how people organize information, and that the value of DSRP lies in making them explicit: distinctions expose assumptions about boundaries and categories, systems reveal what is being treated as the whole and what is left out, relationships surface dependencies, feedback loops and unintended consequences, and perspectives reveal blind spots. He concludes that what is implicit is easy to overlook and what is explicit can be examined, challenged and changed. Applied to Principal Component Analysis, he reports that the four patterns produce an account of how the method works rather than a memorized description of what it does.

## Commentary

### In short

A software engineering newsletter presents DSRP as its mental model of the week, defining all four patterns and applying them to Principal Component Analysis as a worked example.

### In more detail

Calais writes for senior software engineers and engineering managers, and opens with the observation that problems grow more systemic as responsibility grows: a bug is local, but a department optimized in isolation can make a company worse. He offers DSRP as the model that addresses this, attributing it to Derek Cabrera and stating that he first encountered it through the Cabrera Lab Podcast. Each pattern is defined as an act of making something explicit — what things are and how they differ, what forms a whole and how the parts fit, how things are connected and affect one another, and how the same system looks from different points of view. The worked example takes Principal Component Analysis, a dimensionality-reduction technique, and passes it through the four patterns: the distinctions among original variables and the combinations that capture different patterns of variation, the dataset as a whole rather than a set of independent variables, the shared variation that connects those variables, and the transformation into principal components as a new vantage on the same data. Calais notes that this pass was produced by asking a generative AI tool to explain the method through DSRP.

**Patterns it shows** D, S, R, P

**Added** 2026-10-14

**How to cite this** Calais, Pedro (2026). Mental Model of the Week (#2): Sharpen your systems thinking with DSRP. Substack (pcalais.substack.com).