Source
The Twenty Minute VC (20VC): Venture Capital | Startup Funding | The Pitch — 20VC: Who Wins the Inference Market | Has Open-Source LLM Inference Peaked? | What Happens to the Cost of Compute | The Real Limits of Post-Training and RL with Erik Bernhardsson, Modal CEO (November 2, 2026) ·
at 41:33 ▸
When this applies
when deciding whether a task/process is a good candidate for a tight feedback-loop optimization method (training, agentic automation, iterative experimentation)
The takeaway
A process is a good fit for rapid iterative optimization only if it has a fast, well-defined feedback signal; longer feedback loops resist this approach until new mechanisms are found.
Why it works
RL requires a measurable, fast feedback signal to iterate against; tasks like coding (testable in sandboxes) or math (verifiable proofs) have this, while tasks with multi-month human feedback loops don't yet have an analogous mechanism.
One level up
The feedback loop length of a task is often a better predictor of automatability than its apparent complexity.
Where it stops holding
This stops working when new techniques emerge that can simulate or compress long feedback loops (e.g., proxy metrics, simulation environments) that didn't exist before — Bernhardsson himself flags he's 'been wrong for so long' on these predictions.
Detail
rule: Post-training/RL works well for tasks with fast, finite feedback loops (coding, cybersecurity, math); longer feedback-loop tasks remain out of reach for now.
rationale: You can run code in sandboxes and verify success quickly; tasks with multi-week/month human feedback loops lack an equivalent verification mechanism yet.
In their words
I don't know. There's a lot of tasks out there that have way longer feedback loops that I don't know if post-training quite yet is within reach.