The full portfolio This is the same work as the main portfolio, reordered around harness engineering, deterministic pipelines and reproducibility for one role family.

Research Engineering

I build the harness, the pipeline and the verifier.

I build the systems that make a research result trustworthy rather than merely plausible: staged experiment pipelines, deterministic execution, automated testing, and reproducibility and artifact-validation tooling that fails closed rather than open. The same programme appears on the main portfolio; here it is ordered around the engineering first.

Experiment orchestrationDeterministic pipelinesReproducibility & provenanceAutomated testing

Independent researcher Brampton, Ontario, Canada Open to research-engineering roles

What I'd bring

Infrastructure an employer can inspect.

Each of these is a concrete piece of shipped engineering, not a slogan, and each one shows up in one of the two public repositories.

Staged pipeline architecture

An 8-subcommand harness — plan / verify / preflight / freeze-runtime / capture / encode / analyse / report — where each stage refuses to run until its predecessor verifies.

Deterministic, reproducible execution

Seeds derived via HMAC-SHA256 rather than ambient randomness, so a resampling run reproduces exactly; environment-lock verification exits non-zero on drift.

Write-once, tamper-evident publication

Artifacts are published with O_EXCL + O_NOFOLLOW against a directory file descriptor, then fsync'd, with openat-style descriptor-relative path walking to close the TOCTOU window.

Automated verification at scale

Manifests verify 12 root files, 120 nested supplement files and 20 shipped Python files; checksum and environment-lock scripts both exit non-zero on any mismatch.

A large, real test suite

The canonical reproducibility package carries thousands of test functions, run under pytest and GitHub Actions.

Evidence

The evaluation harness and staged execution.

Staged execution Ordered verification Zero failures
Problem
How do you stop a large evaluation run from silently producing invalid data when any one of many stages could fail quietly?
Built
A srop_mech_eval Python package exposing plan / verify / preflight / freeze-runtime / capture / encode / analyse / report as ordered subcommands, where a stage refuses to run until its predecessor verifies.
Scale
20,096 model jobs executed against a frozen schedule with zero failures; 65,536 layer-feature coordinates captured and encoded in a separate mechanistic run.
Methods
Ordered subcommands with hard verification gates between stages, pinned environments, and deterministic HMAC-SHA256-derived seeding so any stage can be re-run exactly.
Result
The staged design caught what a single-script run would have hidden: the harness completed almost every case (98.4% procedural closure) while its own reliability gate correctly identified that the underlying measurement was not yet trustworthy. What this establishes: the orchestration worked as designed. What it does not establish: anything by itself about the model behaviour being measured — that is a separate, already-reported result.

Evidence

The reproducibility and release-verification system.

Verified Write-once Byte-preserved
Problem
Once a research artifact is published, how does anyone — including me, a year later — know the numbers in the paper are the numbers the code actually produces?
Built
A verification system: SHA-256 manifests, write-once publication via O_EXCL/O_NOFOLLOW against a directory file descriptor, checksum scripts, and environment-lock verification, all exiting non-zero on any mismatch.
Scale
Manifests verify 12 root files, 120 nested supplement files and 20 shipped Python files; two predecessor packages of 86 and 201 files carried forward byte-preserved, zero modified.
Methods
Descriptor-relative (openat-style) path walking to close the TOCTOU window between check and use; statistics reimplemented directly on NumPy so verification does not depend on scipy/statsmodels/sklearn version drift.
Result
An independent numerical pass reproduced the published figures directly from the shipped code and manifests. What this establishes: byte- and number-level reproducibility of the release. What it does not establish: the validity of the underlying research claims, which is a separate, already-reported result.

Capability stack

What the infrastructure is built from.

Grouped by what each tool was used for, not as a logo wall — every entry appears in code that ships in a public repository.

Experiment orchestration

  • Staged subcommand pipelines
  • Ordered stage verification
  • Pinned model & environment revisions
  • Python 3.11

Reproducibility & provenance

  • SHA-256 manifests
  • O_EXCL / O_NOFOLLOW write-once publication
  • openat-style descriptor-relative paths
  • Environment lockfiles
  • HMAC-SHA256 derived seeding

Tooling & testing

  • pytest
  • GitHub Actions
  • Thousands of test functions
  • Checksum & drift verification scripts