VEXPOWER
VEXPOWER Marketing Mix Modeling Training Simulator
About
Philosophy
If you can’t measure it, you’re guessing.
Saxifrage started in 2020 as a holding company for growth experiments: thousands of A/B tests, marketing mix models and viral loops, written up so other people could reuse what worked.
The same instinct now points at AI. Most teams ship prompts and agents on vibes because there is no obvious metric. I spend my time building the evals, judges and optimization loops that give you a number — and then making that number go up.
Everything I learn still gets published here. The growth marketing archive is intact; the new work sits alongside it.
Founder
History
Company history
A few milestones, drawn from the projects and posts on this site.
2016
Ladder
Co-founded Ladder, a growth marketing agency that grew to 50 people and ran thousands of experiments for clients like Booking.com.
2017
LinkedIn Learning
Recorded Advanced Google Ads, Excel for Marketers and Marketing Analytics courses for LinkedIn Learning.
2020
Saxifrage founded
Founded as a holding company for growth experiment ideas. Launched Vexpower, a marketing mix modeling training simulator, and Python for Marketers.
2022
Prompt engineering
Started writing about prompt engineering for generative art and copy — the beginning of the AI archive on this blog.
2024
O’Reilly book
Co-authored Prompt Engineering for Generative AI (O’Reilly), after a Udemy bootcamp on the same topic.
2025
Evals
Building synthetic research tools and eval patterns like the Pairwise Gold Triad for subjective LLM tasks.
2026
Second O’Reilly book
Published Context Engineering with DSPy (O’Reilly): self-optimizing prompt pipelines for building reliable AI agents.
Latest work
View all projects
Word of Mouth Coefficient
I worked with former VP of Growth at Eaze Yousuf Bhaijee and Reforge to define a method for calculating Word of Mouth
Zirality Analytics
75% of social traffic is 'direct' meaning there's no marketing source. We found a way to shine a light on this dark traffic.
Get in touchor email m@saxifrage.xyz