diff --git a/CHANGELOG.md b/CHANGELOG.md
index 1a18a4e..6b99cfa 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -8,6 +8,15 @@ Full module documentation: [hexdocs.pm/mob_dev](https://hexdocs.pm/mob_dev).
 
 ---
 
+## [0.5.17]
+
+### Fixed
+- **iOS simulator deploy now boots from a clean `mix mob.deploy --native`** (was device-only). Three gaps made the sim deploy incomplete vs the device path, so the sim crashed on boot even though the device worked:
+  - The Elixir-distribution apps `elixir`/`logger` were staged only under `lib/<app>/ebin`, which the sim's `mob_beam.m` doesn't add to the code path — boot failed at `ensure_all_started(:elixir)` with "elixir.app not found". They're now flattened into the flat BEAMS_DIR alongside `eex` (which already needed this), where the path resolves.
+  - `priv/` was only partially staged (`repo/migrations`), so `Application.app_dir(:<app>, "priv/cacerts.pem")` was `:enoent` and `Mob.Certs.load_cacerts!` crashed the boot. The whole `priv/` is now rsynced into the flat dir (cacerts, `mix`/`hex` ebins, vendored static, …), matching the device release.
+  - `Paths.sim_runtime_dir/0` fell back to `/tmp/otp-ios-sim` for zig-based projects (no `ios/build.sh`), but the runtime is synced to `~/.mob/runtime/ios-sim` — so the launcher and staging disagreed. It now recognizes `ios/build.zig` and returns the default runtime dir.
+  Verified: a clean `mob.deploy --native` to an iPhone 11 Pro Max sim boots Io, Phoenix endpoint up, embedded Livebook home renders — no manual runtime fixups.
+
 ## [0.5.16]
 
 ### Fixed
diff --git a/lib/mob_dev/native_build.ex b/lib/mob_dev/native_build.ex
index 9c8965e..d69ab92 100644
--- a/lib/mob_dev/native_build.ex
+++ b/lib/mob_dev/native_build.ex
@@ -1988,15 +1988,22 @@ defmodule MobDev.NativeBuild do
   end
 
   defp copy_priv_repo_assets(otp_root, app_module) do
-    src = "priv/repo/migrations"
-
-    if File.dir?(src) do
-      IO.puts("  === Copying priv/repo assets")
-      dst = Path.join([otp_root, app_module, "priv/repo/migrations"])
+    # Copy the WHOLE priv/ into BEAMS_DIR/priv (not just repo/migrations), so
+    # Application.app_dir(:<app>, "priv/...") resolves on device/sim — e.g.
+    # priv/cacerts.pem (Mob.Certs.load_cacerts!), priv/mix + priv/hex ebins
+    # (on-device Mix.install), a vendored lib's priv/ (Livebook's static), etc.
+    # Mirrors the device release's full-priv rsync; without it the sim boot
+    # crashed at Mob.Certs.load_cacerts! with :enoent on priv/cacerts.pem.
+    if File.dir?("priv") do
+      IO.puts("  === Copying priv/ (full)")
+      dst = Path.join([otp_root, app_module, "priv"])
       File.mkdir_p!(dst)
+      chmod_writable(dst)
+
+      {_, status} =
+        System.cmd("rsync", ["-a", "--no-perms", "priv/", "#{dst}/"], stderr_to_stdout: true)
 
-      Path.wildcard("#{src}/*.exs")
-      |> Enum.each(&File.cp!(&1, Path.join(dst, Path.basename(&1))))
+      if status != 0, do: raise("rsync priv/ -> #{dst} failed")
     end
 
     :ok
@@ -2027,20 +2034,27 @@ defmodule MobDev.NativeBuild do
   end
 
   defp copy_eex_stdlib_to_app(elixir_lib, otp_root, app_module) do
-    # EEx is part of Elixir but mob_beam.m doesn't add it to the code path.
-    # Drop it into BEAMS_DIR (flat) so code:where_is_file("eex.app") resolves
-    # — Ecto's startup needs it.
-    IO.puts("  === Copying EEx stdlib")
+    # The iOS sim's mob_beam.m doesn't add lib/<app>/ebin to the code path, so
+    # the Elixir-distribution apps that copy_elixir_stdlib_to_otp drops under
+    # lib/ (elixir, logger) — plus eex — are invisible there: boot fails at
+    # `ensure_all_started(:elixir)` with "elixir.app not found". Drop their .app
+    # + beams into BEAMS_DIR (flat), which IS on the path, so they resolve.
+    # (eex was already needed for Ecto's startup; elixir/logger are needed for
+    # the sim to boot at all. Harmless on device, which also has them in lib/.)
+    IO.puts("  === Copying Elixir-distribution apps (elixir, logger, eex) to BEAMS_DIR")
     dst = Path.join(otp_root, app_module)
     File.mkdir_p!(dst)
-    src_ebin = Path.join([elixir_lib, "eex", "ebin"])
 
-    if File.dir?(src_ebin) do
-      Path.wildcard("#{src_ebin}/*.beam")
-      |> Enum.each(&File.cp!(&1, Path.join(dst, Path.basename(&1))))
+    for app <- ~w(elixir logger eex) do
+      src_ebin = Path.join([elixir_lib, app, "ebin"])
+
+      if File.dir?(src_ebin) do
+        Path.wildcard("#{src_ebin}/*.beam")
+        |> Enum.each(&File.cp!(&1, Path.join(dst, Path.basename(&1))))
 
-      app_file = Path.join(src_ebin, "eex.app")
-      if File.exists?(app_file), do: File.cp!(app_file, Path.join(dst, "eex.app"))
+        app_file = Path.join(src_ebin, "#{app}.app")
+        if File.exists?(app_file), do: File.cp!(app_file, Path.join(dst, "#{app}.app"))
+      end
     end
 
     :ok
diff --git a/lib/mob_dev/paths.ex b/lib/mob_dev/paths.ex
index 6927ca7..9b1c883 100644
--- a/lib/mob_dev/paths.ex
+++ b/lib/mob_dev/paths.ex
@@ -39,11 +39,24 @@ defmodule MobDev.Paths do
       build_sh_aware?(project_dir) ->
         default_runtime_dir()
 
+      build_zig?(project_dir) ->
+        # Zig-based iOS builds (ios/build.zig, no ios/build.sh) sync the runtime
+        # to default_runtime_dir() in sync_otp_runtime_sim. The launcher must
+        # agree, or the sim looks in /tmp/otp-ios-sim and boots a non-existent
+        # runtime ("elixir.app not found"). Match the staging path.
+        default_runtime_dir()
+
       true ->
         legacy_tmp_path()
     end
   end
 
+  @doc false
+  @spec build_zig?(String.t()) :: boolean()
+  def build_zig?(project_dir) do
+    File.exists?(Path.join([project_dir, "ios", "build.zig"]))
+  end
+
   @doc """
   The new default runtime path — under `~/.mob/runtime/` so `mix mob.cache`
   can list and clear it the same way it handles the OTP cache.
diff --git a/mix.exs b/mix.exs
index c3d6e9f..e00273b 100644
--- a/mix.exs
+++ b/mix.exs
@@ -4,7 +4,7 @@ defmodule MobDev.MixProject do
   def project do
     [
       app: :mob_dev,
-      version: "0.5.16",
+      version: "0.5.17",
       elixir: "~> 1.19",
       description: "Development tooling for the Mob mobile framework",
       source_url: "https://github.com/genericjam/mob_dev",
diff --git a/test/mob_dev/paths_test.exs b/test/mob_dev/paths_test.exs
index dad36df..5f13861 100644
--- a/test/mob_dev/paths_test.exs
+++ b/test/mob_dev/paths_test.exs
@@ -79,5 +79,12 @@ defmodule MobDev.PathsTest do
       File.write!(Path.join([project, "ios", "build.sh"]), "echo old\n")
       assert Paths.sim_runtime_dir(project_dir: project) == Paths.legacy_tmp_path()
     end
+
+    test "new default for zig-based iOS projects (ios/build.zig, no build.sh)",
+         %{project: project} do
+      System.delete_env("MOB_SIM_RUNTIME_DIR")
+      File.write!(Path.join([project, "ios", "build.zig"]), "// zig build\n")
+      assert Paths.sim_runtime_dir(project_dir: project) == Paths.default_runtime_dir()
+    end
   end
 end