diff --git a/packages/python/tests/e2e/glob_speed_dotfiles_test.py b/packages/python/tests/e2e/glob_speed_dotfiles_test.py
new file mode 100644
index 000000000..15b6d69c1
--- /dev/null
+++ b/packages/python/tests/e2e/glob_speed_dotfiles_test.py
@@ -0,0 +1,129 @@
+"""Glob speed: dotfiles stay hidden unless the pattern spells the dot.
+
+A deep, wide tree where half the top-level directories are dot-named and
+dot-named directories and dotfiles recur below. `'./**/*.md'` must skip
+every one of them; `'./**/.*'` reaches dotfiles because the pattern spells
+the dot, and `'./.cache/**/*.md'` reaches under a dot-named directory
+because the pattern names it. Native is `find` pruning what bash globstar
+with dotglob off would not enter. No mocks: real console script, real
+process, real filesystem.
+"""
+
+from __future__ import annotations
+
+import shutil
+
+import pytest
+
+from .speed_of_light import (
+    assert_speed_of_light,
+    best_of,
+    cli,
+    dirsql_rows,
+    dirsql_timeout,
+    grow_until_native_takes_a_second,
+    hopeless_seconds,
+    startup_seconds,
+    timed,
+)
+
+MARKDOWN = (
+    "find . -mindepth 1 -name '.*' -prune -o -type f -name '*.md' -printf '%P\\n'"
+)
+DOTFILES = "find . -mindepth 1 -name '.*' -prune -type f -printf '%P\\n'"
+UNDER_CACHE = "find .cache -mindepth 1 -name '.*' -prune -o -type f -name '*.md' -print"
+FANOUT = 8
+
+
+def home(i):
+    """The top of item `i`'s subtree: half of them dot-named."""
+    return ("a", "b", ".cache", ".tmp")[i % 4]
+
+
+def build_tree(root, lo, hi):
+    """Items `lo` through `hi - 1`, each a file three directories below its
+    home. Every seventh sits in a dot-named directory, every fifth is a
+    dotfile, and every ninth a `.txt`."""
+    for i in range(lo, hi):
+        j = i // 4
+        folder = (
+            root
+            / home(i)
+            / f"x{j % FANOUT}"
+            / f"y{j // FANOUT % FANOUT}"
+            / f"z{j // FANOUT**2 % FANOUT}"
+        )
+        if i % 7 == 0:
+            folder = folder / ".d"
+        folder.mkdir(parents=True, exist_ok=True)
+        if i % 5 == 0:
+            name = f".h{i}.md"
+        elif i % 9 == 0:
+            name = f"n{i}.txt"
+        else:
+            name = f"n{i}.md"
+        (folder / name).touch()
+
+
+def matched(n, glob):
+    def hit(i):
+        visible = i % 7 != 0
+        markdown = i % 5 != 0 and i % 9 != 0
+        if glob == "./**/*.md":
+            return not home(i).startswith(".") and visible and markdown
+        if glob == "./**/.*":
+            return not home(i).startswith(".") and visible and i % 5 == 0
+        return home(i) == ".cache" and visible and markdown
+
+    return sum(1 for i in range(n) if hit(i))
+
+
+def native(root, script):
+    proc, seconds = timed(["bash", "-c", script], root, timeout=600)
+    assert proc.returncode == 0, proc.stderr
+    return sorted(proc.stdout.splitlines()), seconds
+
+
+def describe_dotfile_glob_speed_of_light():
+    @pytest.fixture
+    def root(tmp_path):
+        tree = tmp_path / "dotfiles"
+        tree.mkdir()
+        try:
+            yield tree
+        finally:
+            shutil.rmtree(tree, ignore_errors=True)
+
+    @pytest.mark.parametrize(
+        ("glob", "script"),
+        [
+            ("./**/*.md", MARKDOWN),
+            ("./**/.*", DOTFILES),
+            ("./.cache/**/*.md", UNDER_CACHE),
+        ],
+    )
+    def it_matches_native_files_within_the_bar(root, glob, script):
+        startup = startup_seconds()
+        n = grow_until_native_takes_a_second(
+            lambda lo, hi: build_tree(root, lo, hi),
+            lambda: native(root, script),
+            start=100_000,
+            ceiling=2**22,
+        )
+        expected, native_seconds = best_of(lambda: native(root, script), "native")
+        assert len(expected) == matched(n, glob)
+
+        def dirsql():
+            proc, seconds = timed(
+                [cli(), "query", f"SELECT path FROM '{glob}'"],
+                root,
+                timeout=dirsql_timeout(native_seconds),
+            )
+            return sorted(row for (row,) in dirsql_rows(proc, ("path",))), seconds
+
+        actual, dirsql_seconds = best_of(
+            dirsql, "dirsql", hopeless_seconds(native_seconds, startup)
+        )
+
+        assert actual == expected
+        assert_speed_of_light(glob, native_seconds, dirsql_seconds, startup)
diff --git a/packages/ts/e2e-attestations/claude-1309-glob-speed.json b/packages/ts/e2e-attestations/claude-1309-glob-speed.json
new file mode 100644
index 000000000..01dbd4e18
--- /dev/null
+++ b/packages/ts/e2e-attestations/claude-1309-glob-speed.json
@@ -0,0 +1,7 @@
+{
+  "command": "pnpm test:e2e",
+  "ran_at": 1791269930,
+  "exit_code": 0,
+  "commit": "3d387a5513bd2e0bf3ab85e12d31eb6c95b130e9",
+  "branch": "claude/1309-glob-speed"
+}