diff --git a/e2e/README.md b/e2e/README.md
index 45b8ad3e..eb942c00 100644
--- a/e2e/README.md
+++ b/e2e/README.md
@@ -1,19 +1,22 @@
 # Checkout Kit End-to-End Tests
 
-This directory contains Maestro end-to-end smoke flows for Checkout Kit sample
-apps.
+This directory contains Maestro end-to-end flows and configuration for Checkout
+Kit sample apps. Two complementary setups live here:
 
-The current runnable suite starts with React Native. It verifies a full guest
-checkout from a seeded cart in the sample app, through Shopify checkout, and
-back to the app after completion.
+- A **local** guest-checkout smoke flow, run with `dev rn e2e`, that exercises a
+  full checkout from a seeded cart through Shopify checkout and back to the app.
+- A **CI matrix** that expands applications, OS version tags, and suites into
+  BrowserStack Maestro run rows, starting with a shared launch smoke.
 
 ## Run locally
 
-Run the matching command from the repo root.
-
 Run `dev up` first to provision the local toolchain. Install Maestro separately
 and make sure `maestro --version` succeeds before running these flows.
 
+### Full guest checkout (`dev rn e2e`)
+
+Run the matching command from the repo root.
+
 React Native iOS:
 
 ```bash
@@ -31,17 +34,90 @@ sample app, then run Maestro. They require the standard storefront `.env` setup,
 but the E2E flow seeds its own cart through the bootstrap deep link; no manual
 sample cart setup is required.
 
+### Shared launch smoke
+
+The launch smoke launches a sample app and waits for the shared ready marker
+exposed by that app, using the same environment contract used by CI.
+
+React Native iOS:
+
+```bash
+E2E_APP_ID=com.shopify.checkoutkit.reactnativedemo \
+E2E_READY_MARKER=checkout-kit-sample-ready \
+maestro --platform ios test e2e/tests/shared/launch-smoke.yaml
+```
+
+React Native Android:
+
+```bash
+E2E_APP_ID=com.shopify.checkoutkit.reactnativedemo \
+E2E_READY_MARKER=checkout-kit-sample-ready \
+maestro --platform android test e2e/tests/shared/launch-smoke.yaml
+```
+
+React Native E2E runs should use the released native SDK artifacts declared by
+the React Native sample configuration, not local in-repo native SDK overrides.
+
+## Matrix
+
+CI runs are described by `config/matrix.yml`. The matrix expands applications, OS
+version tags, and suites into BrowserStack Maestro run rows. Because Bitrise has no
+built-in matrix support, `e2e/lib/e2e_matrix.rb` performs the expansion and the
+pipeline parallelizes over the resulting rows.
+
+Current applications:
+
+- React Native iOS sample app
+- React Native Android sample app
+
+Current OS version tags:
+
+- `latest`
+
+Current suites:
+
+- `tests/shared/launch-smoke.yaml`
+
+Validate the matrix:
+
+```bash
+ruby e2e/scripts/e2e_matrix validate
+```
+
+Expand all run rows:
+
+```bash
+ruby e2e/scripts/e2e_matrix expand
+```
+
+Expand a single run row by index:
+
+```bash
+ruby e2e/scripts/e2e_matrix expand --index 0
+```
+
 ## Files
 
 - `config.yaml` configures Maestro for shared platform behavior.
 - `flows/` contains reusable Maestro subflows for app setup and checkout steps.
 - `tests/react-native/full-guest-checkout.yaml` composes the React Native guest
   checkout smoke test from those subflows.
+- `config/matrix.yml`, `lib/e2e_matrix.rb`, and `scripts/` drive the CI matrix.
+- `tests/shared/launch-smoke.yaml` is the shared launch smoke suite.
+
+## Shared app contract
+
+Shared flows rely on stable cross-app identifiers. The launch smoke requires each
+target app to expose this ready marker:
+
+- `checkout-kit-sample-ready`
+
+Future shared flows should add identifiers here before they are used across
+React Native, Swift, and Android sample apps.
 
 ## Scope
 
-This smoke flow is intended to catch regressions in the React Native sample app
-integration surface: cart bootstrap, checkout presentation, checkout
-completion, and return to the sample app. It is not a replacement for
-checkout-web's browser-based coverage or for future native Swift and Android
-sample-app E2E coverage.
+These flows catch regressions in the React Native sample app integration
+surface: cart bootstrap, checkout presentation, checkout completion, and return
+to the sample app. They are not a replacement for checkout-web's browser-based
+coverage or for future native Swift and Android sample-app E2E coverage.
diff --git a/e2e/config/matrix.yml b/e2e/config/matrix.yml
new file mode 100644
index 00000000..53608764
--- /dev/null
+++ b/e2e/config/matrix.yml
@@ -0,0 +1,19 @@
+version: 1
+applications:
+  - id: react-native-ios
+    target: react-native
+    platform: ios
+    app_id: com.shopify.checkoutkit.reactnativedemo
+    artifact_env: E2E_REACT_NATIVE_IOS_APP_PATH
+    ready_marker: checkout-kit-sample-ready
+  - id: react-native-android
+    target: react-native
+    platform: android
+    app_id: com.shopify.checkoutkit.reactnativedemo
+    artifact_env: E2E_REACT_NATIVE_ANDROID_APP_PATH
+    ready_marker: checkout-kit-sample-ready
+os_version_tags:
+  - latest
+suites:
+  - id: launch-smoke
+    execute: tests/shared/launch-smoke.yaml
diff --git a/e2e/lib/e2e_matrix.rb b/e2e/lib/e2e_matrix.rb
new file mode 100644
index 00000000..3e780dab
--- /dev/null
+++ b/e2e/lib/e2e_matrix.rb
@@ -0,0 +1,168 @@
+# frozen_string_literal: true
+
+require "yaml"
+
+# Expands the compact E2E test matrix in config/matrix.yml into one fully-resolved
+# run per (application x os_version_tag x suite) combination.
+#
+# Unlike GitHub Actions, Bitrise has no built-in matrix/strategy support, so we
+# do the fan-out ourselves: `expand` produces the JSON list of runs that the
+# pipeline consumes, and Bitrise parallelizes over it via `run_at`/`count`.
+#
+# Today the numbers make the config and the expansion look equivalent -
+# 2 applications + 1 os_version_tag + 1 suite, and 2 * 1 * 1 = 2 runs - so it can look
+# like a plain YAML-to-JSON copy. The point is the multiplication, not the copy:
+# adding a single os_version_tag (e.g. a minimum-supported OS) transparently duplicates
+# every application x suite across that OS, turning an additive config change into
+# a multiplicative set of runs without hand-writing each one.
+class E2EMatrix
+  attr_reader :config_path
+
+  def self.load(config_path)
+    new(config_path, YAML.safe_load_file(config_path))
+  end
+
+  def initialize(config_path, config)
+    @config_path = config_path
+    @config = config || {}
+  end
+
+  def expand
+    applications.flat_map do |application|
+      os_version_tags.flat_map do |os_version_tag|
+        suites.map do |suite|
+          build_run(application, os_version_tag, suite)
+        end
+      end
+    end
+  end
+
+  def run_at(index)
+    runs = expand
+    unless index.is_a?(Integer) && index >= 0 && index < runs.length
+      raise IndexError, "index #{index} outside of run range 0...#{runs.length}"
+    end
+
+    runs.fetch(index)
+  end
+
+  def validation_errors
+    errors = []
+    errors << "version must be 1" unless @config.fetch("version", nil) == 1
+    validate_collection(errors, "applications", applications)
+    validate_collection(errors, "os_version_tags", os_version_tags)
+    validate_collection(errors, "suites", suites)
+    validate_applications(errors)
+    validate_os_version_tags(errors)
+    validate_suites(errors)
+    errors
+  end
+
+  private
+
+  def build_run(application, os_version_tag, suite)
+    platform = application.fetch("platform")
+    os_version_tag_id = os_version_tag_id(os_version_tag)
+    suite_id = suite.fetch("id")
+    application_id = application.fetch("id")
+
+    {
+      "id" => "#{application_id}-#{os_version_tag_id}-#{suite_id}",
+      "application_id" => application_id,
+      "target" => application.fetch("target"),
+      "platform" => platform,
+      "os_version_tag" => os_version_tag_id,
+      "device_selector" => device_selector(platform, os_version_tag),
+      "app_id" => application.fetch("app_id"),
+      "artifact_env" => application.fetch("artifact_env"),
+      "execute" => suite.fetch("execute"),
+      "ready_marker" => application.fetch("ready_marker"),
+      "status_context" => "checkout-kit/e2e/#{application_id}/#{os_version_tag_id}/#{suite_id}"
+    }
+  end
+
+  def device_selector(platform, os_version_tag)
+    return os_version_tag.fetch("device_selector") if os_version_tag.is_a?(Hash) && os_version_tag.key?("device_selector")
+
+    "#{platform}:phone:#{os_version_tag_id(os_version_tag)}"
+  end
+
+  def os_version_tag_id(os_version_tag)
+    os_version_tag.is_a?(Hash) ? os_version_tag.fetch("id") : os_version_tag
+  end
+
+  def applications
+    @config.fetch("applications", []) || []
+  end
+
+  def os_version_tags
+    @config.fetch("os_version_tags", []) || []
+  end
+
+  def suites
+    @config.fetch("suites", []) || []
+  end
+
+  def validate_collection(errors, name, collection)
+    errors << "#{name} must be a non-empty array" unless collection.is_a?(Array) && !collection.empty?
+  end
+
+  def validate_applications(errors)
+    return unless applications.is_a?(Array)
+
+    validate_unique_ids(errors, "application", applications)
+    applications.each do |application|
+      id = application.fetch("id", "<missing>")
+      required_application_keys.each do |key|
+        errors << "application #{id} missing #{key}" if application.fetch(key, "").to_s.empty?
+      end
+      platform = application.fetch("platform", nil)
+      errors << "application #{id} platform must be ios or android" unless ["ios", "android"].include?(platform)
+    end
+  end
+
+  def validate_os_version_tags(errors)
+    return unless os_version_tags.is_a?(Array)
+
+    ids = os_version_tags.map { |os_version_tag| safe_os_version_tag_id(os_version_tag) }
+    errors << "os_version_tag ids must be unique" unless ids.compact.uniq.length == ids.compact.length
+    os_version_tags.each do |os_version_tag|
+      id = safe_os_version_tag_id(os_version_tag)
+      errors << "os_version_tag missing id" if id.to_s.empty?
+    end
+  end
+
+  def safe_os_version_tag_id(os_version_tag)
+    os_version_tag_id(os_version_tag)
+  rescue KeyError
+    nil
+  end
+
+  def validate_suites(errors)
+    return unless suites.is_a?(Array)
+
+    validate_unique_ids(errors, "suite", suites)
+    suites.each do |suite|
+      id = suite.fetch("id", "")
+      errors << "suite missing id" if id.to_s.empty?
+      execute = suite.fetch("execute", "")
+      errors << "suite #{id} missing execute" if execute.empty?
+      next if execute.empty?
+
+      errors << "suite #{id} execute path does not exist: #{execute}" unless File.exist?(File.join(e2e_root, execute))
+    end
+  end
+
+  def validate_unique_ids(errors, label, collection)
+    ids = collection.map { |item| item.fetch("id", nil) }
+    errors << "#{label} ids must be unique" unless ids.compact.uniq.length == ids.compact.length
+  end
+
+  def required_application_keys
+    ["id", "target", "platform", "app_id", "artifact_env", "ready_marker"]
+  end
+
+  def e2e_root
+    File.expand_path("..", File.dirname(config_path))
+  end
+end
diff --git a/e2e/scripts/e2e_matrix b/e2e/scripts/e2e_matrix
new file mode 100755
index 00000000..de97ae08
--- /dev/null
+++ b/e2e/scripts/e2e_matrix
@@ -0,0 +1,51 @@
+#!/usr/bin/env ruby
+# frozen_string_literal: true
+
+require "json"
+require "optparse"
+require_relative "../lib/e2e_matrix"
+
+options = {
+  config: File.expand_path("../config/matrix.yml", __dir__)
+}
+
+parser = OptionParser.new do |opts|
+  opts.banner = "Usage: e2e/scripts/e2e_matrix validate|expand [options]"
+  opts.on("--config PATH") { |path| options[:config] = path }
+  opts.on("--index INDEX", Integer) { |index| options[:index] = index }
+end
+
+command = ARGV.shift
+parser.parse!(ARGV)
+
+unless ["validate", "expand"].include?(command)
+  warn parser
+  exit 1
+end
+
+matrix = E2EMatrix.load(options.fetch(:config))
+
+case command
+when "validate"
+  errors = matrix.validation_errors
+  if errors.empty?
+    puts "E2E matrix is valid"
+  else
+    warn errors.join("\n")
+    exit 1
+  end
+when "expand"
+  errors = matrix.validation_errors
+  unless errors.empty?
+    warn errors.join("\n")
+    exit 1
+  end
+
+  output = if options.key?(:index)
+    matrix.run_at(options.fetch(:index))
+  else
+    matrix.expand
+  end
+
+  puts JSON.pretty_generate(output)
+end
diff --git a/e2e/tests/shared/launch-smoke.yaml b/e2e/tests/shared/launch-smoke.yaml
new file mode 100644
index 00000000..5f534a86
--- /dev/null
+++ b/e2e/tests/shared/launch-smoke.yaml
@@ -0,0 +1,7 @@
+appId: ${E2E_APP_ID}
+---
+- launchApp
+- extendedWaitUntil:
+    visible:
+      id: ${E2E_READY_MARKER}
+    timeout: 60000