AI Interview Prep

AI Interview Prep

Generative Vision Interview Questions #17 - The Perceived Noise Paradox

How zero-mean noise silently destroys your high-res diffusion training, and the timestep shifting trick that rescues your detail-defining steps from being averaged away.

Hao Hoang's avatar
Hao Hoang
Jun 25, 2026
∙ Paid

We’re in a Senior ML Engineer interview at Midjourney and the interviewer asks:

“You trained a diffusion model that’s gorgeous at 256px. You scale it to 1024px, keep the exact same noise schedule, and the outputs get quietly worse. Same architecture, same loss, same schedule. What broke?”

Don’t say: “The schedule is resolution-agnostic, so I’d just train …

User's avatar

Continue reading this post for free, courtesy of Hao Hoang.

Or purchase a paid subscription.
© 2026 Hao Hoang · Privacy ∙ Terms ∙ Collection notice
Start your SubstackGet the app
Substack is the home for great culture