Thoughts

Sparse autoencoders just turned interpretability into feature engineering

We're not making AI more transparent, we're just building better debugging tools for black boxes.

The interpretability crowd has been banging on about understanding AI internals for years. Now sparse autoencoders are giving us exactly what we asked for, and it looks suspiciously like old-school feature engineering with extra steps.

The feature extraction pipeline returns

Sparse autoencoders decompose model activations into supposedly meaningful components. We extract features, analyse patterns, and build tools around these decomposed representations. Sound familiar? We’ve just rebuilt the entire feature engineering pipeline that deep learning was meant to replace.

The difference is scale and automation. Instead of hand-crafting features from raw data, we’re auto-extracting them from learned representations. We’re not interpreting the model so much as building a secondary model to explain the first one.

Black boxes all the way down

Here’s the uncomfortable truth. Those sparse autoencoder features aren’t inherently more interpretable than the original activations. We’ve just pushed the black box problem one layer deeper. We still need human judgement to decide which features matter and what they actually represent.

The real value isn’t transparency. It’s tooling. We’re building sophisticated debugging instruments for complex systems, and that’s genuinely useful. We just need to stop pretending it’s the same as understanding how the system actually works.

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