diff --git a/.buildkite/pipeline.yml b/.buildkite/pipeline.yml
new file mode 100644
index 0000000..c491a16
--- /dev/null
+++ b/.buildkite/pipeline.yml
@@ -0,0 +1,91 @@
+env:
+  CARGO_TERM_COLOR: always
+
+steps:
+  - label: ":linux: Linux ARM64"
+    key: linux-arm64
+    concurrency: 2
+    concurrency_group: "big-cabbage/tart-ci"
+    agents:
+      queue: "ci-linux-arm64"
+    plugins:
+      - github.com/Bande-a-Bonnot/tart-ci#v0.1.1:
+          image: "ci-linux-arm64-rust-bazel"
+          os: "linux"
+          always_pull: false
+          headless: true
+    command: |
+      set -euo pipefail
+
+      if [[ -z "$${HOME:-}" || "$$HOME" == "/" ]]; then
+        export HOME=/home/admin
+      fi
+      export CARGO_HOME="$${CARGO_HOME:-$$HOME/.cargo}"
+      export RUSTUP_HOME="$${RUSTUP_HOME:-/opt/rustup}"
+      export PATH="/usr/local/bin:/opt/cargo/bin:$$CARGO_HOME/bin:$$PATH"
+
+      rustc --version
+      cargo --version
+      python3 --version
+
+      cd middens
+      cargo fmt --check
+      cargo test --locked --lib
+      cargo test --locked --test cucumber -- --input tests/features/smoke.feature
+      cargo build --release --locked
+
+      smoke_output="$$(mktemp -d)"
+      smoke_xdg="$$(mktemp -d)"
+      XDG_DATA_HOME="$$smoke_xdg" ./target/release/middens analyze tests/fixtures --split --no-python --output "$$smoke_output"
+      test -f "$$smoke_output/interactive/markov.json"
+      test -f "$$smoke_output/subagent/markov.json"
+      test -f "$$smoke_output/autonomous/markov.json"
+
+  - label: ":mac: macOS Apple Silicon"
+    key: macos-apple-silicon
+    concurrency: 2
+    concurrency_group: "big-cabbage/tart-ci"
+    agents:
+      queue: "ci-macos-apple-silicon"
+    plugins:
+      - github.com/Bande-a-Bonnot/tart-ci#v0.1.1:
+          image: "ghcr.io/cirruslabs/macos-sequoia-base:latest"
+          os: "macos"
+          always_pull: false
+          headless: true
+    command: |
+      set -euo pipefail
+
+      if [[ -z "$${HOME:-}" ]]; then
+        export HOME=/Users/admin
+      fi
+      export CARGO_HOME="$${CARGO_HOME:-$$HOME/.cargo}"
+      export RUSTUP_HOME="$${RUSTUP_HOME:-$$HOME/.rustup}"
+      export PATH="$$CARGO_HOME/bin:/opt/homebrew/bin:/usr/local/bin:$$PATH"
+
+      if ! command -v cargo >/dev/null 2>&1; then
+        curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs \
+          | HOME="$$HOME" CARGO_HOME="$$CARGO_HOME" RUSTUP_HOME="$$RUSTUP_HOME" sh -s -- -y --profile minimal --no-modify-path
+        . "$$CARGO_HOME/env"
+      fi
+
+      if command -v rustup >/dev/null 2>&1; then
+        rustup component add rustfmt
+      fi
+
+      rustc --version
+      cargo --version
+      python3 --version
+
+      cd middens
+      cargo fmt --check
+      cargo test --locked --lib
+      cargo test --locked --test cucumber -- --input tests/features/smoke.feature
+      cargo build --release --locked
+
+      smoke_output="$$(mktemp -d)"
+      smoke_xdg="$$(mktemp -d)"
+      XDG_DATA_HOME="$$smoke_xdg" ./target/release/middens analyze tests/fixtures --split --no-python --output "$$smoke_output"
+      test -f "$$smoke_output/interactive/markov.json"
+      test -f "$$smoke_output/subagent/markov.json"
+      test -f "$$smoke_output/autonomous/markov.json"
diff --git a/docs/HANDOFF.md b/docs/HANDOFF.md
index bc9cff6..c1ae4eb 100644
--- a/docs/HANDOFF.md
+++ b/docs/HANDOFF.md
@@ -1,11 +1,17 @@
 # Session Handoff
 
-**Last updated:** 2026-06-04 (public results trusted smoke/deploy green)
+**Last updated:** 2026-06-09 (Buildkite/Tart CI PR rebased on public-results work)
 
 Read this at the start of every session. Update before compaction or at natural milestones.
 
 ---
 
+## Current session update — 2026-06-01
+
+Started Buildkite/Tart CI migration on branch `chore/buildkite-tart-ci`. Added `.buildkite/pipeline.yml` with two non-credentialed PR jobs using `github.com/Bande-a-Bonnot/tart-ci#v0.1.1`: Linux ARM64 on local image `ci-linux-arm64-rust-bazel`, and macOS Apple Silicon on `ghcr.io/cirruslabs/macos-sequoia-base:latest` with Rust bootstrapped by rustup. The first slice intentionally covers lightweight Middens cross-platform checks: `cargo fmt --check`, `cargo test --locked --lib`, the Cucumber harness smoke feature, `cargo build --release --locked`, and `middens analyze tests/fixtures --split --no-python` with checks for all three stratum outputs. The full Cucumber/HF corpus batteries, scheduled workflows, release artifacts, x86_64 targets, Hugging Face registry/secrets, and large network downloads remain on GitHub Actions/deferred.
+
+Local validation before PR, after merging latest `origin/main`: `cd middens && cargo fmt --check`, `cargo test --locked --lib` (31 unit tests), Cucumber smoke feature, `cargo build --release --locked`, fixture split/no-python smoke, Buildkite YAML parse with Ruby, `bash -n` over both embedded commands after Buildkite dollar escaping, and `git diff --check` all passed. Full `cargo test --locked` was attempted after the latest main merge but exceeded the local harness timeout twice (>20 minutes), so it is intentionally left to the existing GitHub HF/full test workflow rather than the first Tart smoke slice. A small rustfmt-only fix was included for `middens/tests/steps/split.rs` because latest `main` had one formatting drift that would fail the new CI slice. `cargo clippy --all-targets --locked -- -D warnings` was tried before merging latest `main` but is not included in the first CI slice because current code has many pre-existing clippy warnings under the local/newer toolchain. Remote `buildkite-agent pipeline upload --dry-run` on `big-cabbage` was attempted but blocked by intermittent SSH publickey auth from this session; no host/config/image changes were made. Existing GitHub Actions `Build public results site` initially failed on PR #3; Azure-backed log/artifact downloads were unreachable from this workstation, but workflow inspection found a likely artifact path mismatch where downloaded artifacts may contain `site-data/corpora/...` instead of `.tmp/site-data/corpora/...`. The PR branch now accepts both path shapes in the collector; workflow YAML and a local `find` fixture validated.
+
 ## >>> Read this first <<<
 
 **All 23 techniques are working. Zero errors, zero timeouts on 13,423 sessions (commit `867f57b`).**
diff --git a/middens/tests/steps/split.rs b/middens/tests/steps/split.rs
index bb3ac08..4eb3c62 100644
--- a/middens/tests/steps/split.rs
+++ b/middens/tests/steps/split.rs
@@ -206,7 +206,13 @@ fn when_run_middens_analyze_with_split_on_the_mixed_corpus_using_technique(
     run_analyze_with_args(
         world,
         true,
-        &["--techniques", technique.as_str(), "--timeout", "1800", "--force"],
+        &[
+            "--techniques",
+            technique.as_str(),
+            "--timeout",
+            "1800",
+            "--force",
+        ],
     );
 }