See it
Run the same review twice.
Same document, same requirement, repeated runs. A conventional LLM stack drifts. HaloRT does not. Watch the digest column as the runs stack up.
Input
case-88421.pdf → REQ-0148 v4
Executing run 1
Conventional LLM stack
—
Output digest changes between runs. An examiner cannot re-derive the finding, so the control cannot be evidenced by re-execution.
HaloRT
—
Identical digest, identical finding, identical cited extract. The run is evidence, and it can be reproduced on demand.
How
Determinism is engineered, not requested.
Setting a temperature to zero does not make a model reproducible. Drift comes from execution order, floating-point non-associativity, batching, hardware scheduling and silent model or configuration changes. HaloRT closes each of those.
01
Fixed execution order
Reduction and accumulation order is fixed, independent of batch composition or concurrency. Two runs perform the same operations in the same sequence.
02
Pinned numerics
Precision, kernel selection and rounding behaviour are pinned to the run, so hardware and driver changes cannot silently move an output.
03
Sealed model & config
Model weights, prompt scaffolding, tokeniser and decoding settings are sealed together and content-addressed. There is no "the model was updated" explanation available.
04
Signed run manifest
Every run emits a manifest — inputs, ruleset version, sealed model digest, environment — signed and stored with the finding. Reproduction is a command, not an investigation.
Why it matters
Four things determinism buys you that probabilistic tooling cannot.
Evidence that survives re-examination
A finding from 2024 can be re-executed in 2028 and return the same result. That is the difference between an audit artefact and an anecdote.
Rule changes with a real diff
Re-run a population under a new interpretation and every difference is attributable to the change — not to model variance. Interpretation changes become testable.
Validation and qualification are possible
Regulated quality systems require documented evidence that a computerised system performs consistently. Reproducibility makes that testable rather than aspirational.
Consistency across the population
Two identical cases receive an identical outcome — including two identical cases six months apart, in different regions, handled by different teams.