[7/N] feat(sqsim): wire modeled adapters into local stack

service/runway/server/BUILD.bazel

@@ -1,4 +1,4 @@
-load("@rules_go//go:def.bzl", "go_binary", "go_library")
+load("@rules_go//go:def.bzl", "go_binary", "go_library", "go_test")
 
 go_library(
     name = "go_default_library",
@@ -19,6 +19,8 @@ go_library(
         "//runway/controller/mergeconflictcheck:go_default_library",
         "//runway/extension/merger:go_default_library",
         "//runway/extension/merger/noop:go_default_library",
+        "//sqsim/adapter/merger:go_default_library",
+        "//sqsim/model:go_default_library",
         "@com_github_go_sql_driver_mysql//:go_default_library",
         "@com_github_uber_go_tally//:go_default_library",
         "@org_golang_google_grpc//:go_default_library",
@@ -32,3 +34,16 @@ go_binary(
     embed = [":go_default_library"],
     visibility = ["//visibility:public"],
 )
+
+go_test(
+    name = "go_default_test",
+    srcs = ["main_test.go"],
+    embed = [":go_default_library"],
+    deps = [
+        "//runway/extension/merger:go_default_library",
+        "//sqsim/model:go_default_library",
+        "//sqsim/scenarios:go_default_library",
+        "@com_github_stretchr_testify//assert:go_default_library",
+        "@com_github_stretchr_testify//require:go_default_library",
+    ],
+)

service/runway/server/docker-compose.yml

@@ -41,6 +41,9 @@ services:
       # Queue infrastructure connection
       - QUEUE_MYSQL_DSN=root:root@tcp(mysql-queue:3306)/submitqueue?parseTime=true
       - HOSTNAME=runway-dev
+      - SQSIM_SCENARIO_PATH=${SQSIM_SCENARIO_PATH:-}
+    volumes:
+      - ${SQSIM_PROFILE_DIR:-../../../sqsim}:/sqsim:ro
     depends_on:
       mysql-queue:
         condition: service_healthy

service/runway/server/main.go

@@ -41,6 +41,8 @@ import (
 	"github.com/uber/submitqueue/runway/controller/mergeconflictcheck"
 	"github.com/uber/submitqueue/runway/extension/merger"
 	"github.com/uber/submitqueue/runway/extension/merger/noop"
+	simmerger "github.com/uber/submitqueue/sqsim/adapter/merger"
+	"github.com/uber/submitqueue/sqsim/model"
 	"go.uber.org/zap"
 	"google.golang.org/grpc"
 	"google.golang.org/grpc/reflection"
@@ -115,6 +117,11 @@ func run() error {
 		metricsWgDone.Wait()
 	}()
 
+	sqsimRuntime, err := loadSQSimRuntime(os.Getenv("SQSIM_SCENARIO_PATH"))
+	if err != nil {
+		return err
+	}
+
 	queueDSN := os.Getenv("QUEUE_MYSQL_DSN")
 	if queueDSN == "" {
 		return fmt.Errorf("QUEUE_MYSQL_DSN environment variable is required")
@@ -147,14 +154,18 @@ func run() error {
 		return fmt.Errorf("failed to create topic registry: %w", err)
 	}
 
+	classifiers := []errs.Classifier{
+		genericerrs.Classifier,
+		mysqlerrs.Classifier,
+	}
+	if sqsimRuntime != nil {
+		classifiers = append(classifiers, model.Classifier)
+	}
 	primaryConsumer := consumer.New(logger.Sugar(), scope.SubScope("consumer"), registry,
-		errs.NewClassifierProcessor(
-			genericerrs.Classifier,
-			mysqlerrs.Classifier,
-		),
+		errs.NewClassifierProcessor(classifiers...),
 	)
 
-	mergerFactory := newMergerFactory()
+	mergerFactory := newMergerFactory(sqsimRuntime)
 
 	mergeConflictCheckController := mergeconflictcheck.NewController(mergeconflictcheck.Params{
 		Logger:        logger.Sugar(),
@@ -245,16 +256,40 @@ func run() error {
 
 // newMergerFactory returns a merger.Factory for the example server. The noop
 // implementation always succeeds; a real deployment wires a VCS-backed factory.
-func newMergerFactory() merger.Factory {
-	return &noopMergerFactory{}
+func newMergerFactory(sqsimRuntime *model.Runtime) merger.Factory {
+	factory := &routingMergerFactory{}
+	if sqsimRuntime != nil {
+		factory.sqsim = simmerger.New(sqsimRuntime, "sqsim")
+	}
+	return factory
 }
 
-type noopMergerFactory struct{}
+type routingMergerFactory struct {
+	sqsim merger.Merger
+}
 
-func (f *noopMergerFactory) For(_ merger.Config) (merger.Merger, error) {
+func (f *routingMergerFactory) For(cfg merger.Config) (merger.Merger, error) {
+	if cfg.QueueName == "sqsim" && f.sqsim != nil {
+		return f.sqsim, nil
+	}
 	return noop.New(), nil
 }
 
+func loadSQSimRuntime(path string) (*model.Runtime, error) {
+	if path == "" {
+		return nil, nil
+	}
+	profile, err := model.Load(path)
+	if err != nil {
+		return nil, fmt.Errorf("load SQSim profile: %w", err)
+	}
+	runtime, err := model.NewRuntime(profile, model.RealClock{})
+	if err != nil {
+		return nil, fmt.Errorf("initialize SQSim runtime: %w", err)
+	}
+	return runtime, nil
+}
+
 // newTopicRegistry builds the TopicRegistry for Runway's merge queues. Inbound
 // topics (merge-conflict-check, merge) have subscriptions; outbound signal topics
 // are publish-only.

service/runway/server/main_test.go

@@ -0,0 +1,51 @@
+// Copyright (c) 2026 Uber Technologies, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package main
+
+import (
+	"path/filepath"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+	"github.com/uber/submitqueue/runway/extension/merger"
+	"github.com/uber/submitqueue/sqsim/model"
+	"github.com/uber/submitqueue/sqsim/scenarios"
+)
+
+func TestSQSimMergerFactoryIsOptIn(t *testing.T) {
+	defaultFactory := newMergerFactory(nil)
+	first, err := defaultFactory.For(merger.Config{QueueName: "sqsim"})
+	require.NoError(t, err)
+	second, err := defaultFactory.For(merger.Config{QueueName: "sqsim"})
+	require.NoError(t, err)
+	assert.NotSame(t, first, second)
+
+	scenario, err := scenarios.HappyPath()
+	require.NoError(t, err)
+	profile, err := model.Compile("happy-path", scenario)
+	require.NoError(t, err)
+	path := filepath.Join(t.TempDir(), "profile.json")
+	require.NoError(t, model.Write(path, profile))
+	runtime, err := loadSQSimRuntime(path)
+	require.NoError(t, err)
+
+	sqsimFactory := newMergerFactory(runtime)
+	first, err = sqsimFactory.For(merger.Config{QueueName: "sqsim"})
+	require.NoError(t, err)
+	second, err = sqsimFactory.For(merger.Config{QueueName: "sqsim"})
+	require.NoError(t, err)
+	assert.Same(t, first, second)
+}

service/submitqueue/docker-compose.yml

@@ -76,6 +76,9 @@ services:
       # Queue infrastructure connection (separate database)
       - QUEUE_MYSQL_DSN=root:root@tcp(mysql-queue:3306)/submitqueue?parseTime=true
       - HOSTNAME=orchestrator-dev
+      - SQSIM_SCENARIO_PATH=${SQSIM_SCENARIO_PATH:-}
+    volumes:
+      - ${SQSIM_PROFILE_DIR:-../../sqsim}:/sqsim:ro
     depends_on:
       mysql-app:
         condition: service_healthy
@@ -98,6 +101,9 @@ services:
       # Queue infrastructure connection (shared with the orchestrator)
       - QUEUE_MYSQL_DSN=root:root@tcp(mysql-queue:3306)/submitqueue?parseTime=true
       - HOSTNAME=runway-dev
+      - SQSIM_SCENARIO_PATH=${SQSIM_SCENARIO_PATH:-}
+    volumes:
+      - ${SQSIM_PROFILE_DIR:-../../sqsim}:/sqsim:ro
     depends_on:
       mysql-queue:
         condition: service_healthy

service/submitqueue/gateway/server/queues.yaml

@@ -4,6 +4,7 @@
 # VCS configuration lives in the extension factory implementations wired in the
 # server, not here.
 queues:
+  - name: sqsim
   - name: test-queue
   - name: e2e-test-queue
   - name: e2e-cancel-queue

service/submitqueue/orchestrator/server/BUILD.bazel

@@ -1,12 +1,12 @@
-load("@rules_go//go:def.bzl", "go_binary", "go_library")
+load("@rules_go//go:def.bzl", "go_binary", "go_library", "go_test")
 
 exports_files(
     ["docker-compose.yml"],
     visibility = ["//visibility:public"],
 )
 
 go_library(
-    name = "orchestrator_lib",
+    name = "go_default_library",
     srcs = ["main.go"],
     importpath = "github.com/uber/submitqueue/service/submitqueue/orchestrator/server",
     visibility = ["//visibility:private"],
@@ -22,6 +22,8 @@ go_library(
         "//platform/extension/messagequeue:go_default_library",
         "//platform/extension/messagequeue/mysql:go_default_library",
         "//platform/http:go_default_library",
+        "//sqsim/adapter/buildrunner:go_default_library",
+        "//sqsim/model:go_default_library",
         "//submitqueue/core/changeset:go_default_library",
         "//submitqueue/core/topickey:go_default_library",
         "//submitqueue/entity:go_default_library",
@@ -73,6 +75,18 @@ go_library(
 
 go_binary(
     name = "orchestrator",
-    embed = [":orchestrator_lib"],
+    embed = [":go_default_library"],
     visibility = ["//visibility:public"],
 )
+
+go_test(
+    name = "go_default_test",
+    srcs = ["main_test.go"],
+    embed = [":go_default_library"],
+    deps = [
+        "//sqsim/model:go_default_library",
+        "//sqsim/scenarios:go_default_library",
+        "@com_github_stretchr_testify//assert:go_default_library",
+        "@com_github_stretchr_testify//require:go_default_library",
+    ],
+)

service/submitqueue/orchestrator/server/docker-compose.yml

@@ -54,6 +54,9 @@ services:
       # Queue infrastructure connection (separate database)
       - QUEUE_MYSQL_DSN=root:root@tcp(mysql-queue:3306)/submitqueue?parseTime=true
       - HOSTNAME=orchestrator-dev
+      - SQSIM_SCENARIO_PATH=${SQSIM_SCENARIO_PATH:-}
+    volumes:
+      - ${SQSIM_PROFILE_DIR:-../../../../sqsim}:/sqsim:ro
     depends_on:
       mysql-app:
         condition: service_healthy

service/submitqueue/orchestrator/server/main.go

@@ -42,6 +42,8 @@ import (
 	extqueue "github.com/uber/submitqueue/platform/extension/messagequeue"
 	queueMySQL "github.com/uber/submitqueue/platform/extension/messagequeue/mysql"
 	"github.com/uber/submitqueue/platform/http"
+	simbuildrunner "github.com/uber/submitqueue/sqsim/adapter/buildrunner"
+	"github.com/uber/submitqueue/sqsim/model"
 	"github.com/uber/submitqueue/submitqueue/core/changeset"
 	"github.com/uber/submitqueue/submitqueue/core/topickey"
 	"github.com/uber/submitqueue/submitqueue/entity"
@@ -159,6 +161,11 @@ func run() error {
 		metricsWgDone.Wait()
 	}()
 
+	sqsimRuntime, err := loadSQSimRuntime(os.Getenv("SQSIM_SCENARIO_PATH"))
+	if err != nil {
+		return err
+	}
+
 	// Open app database connection for counter
 	// Docker Compose healthchecks ensure MySQL is ready before service starts
 	appDSN := os.Getenv("MYSQL_DSN")
@@ -220,14 +227,18 @@ func run() error {
 	// so every non-nil error from a DLQ controller is forced retryable —
 	// reconciliation must redeliver on any failure because the DLQ
 	// subscriptions are final destinations (there is no further DLQ).
+	classifiers := []errs.Classifier{
+		genericerrs.Classifier,
+		// Storage (submitqueue/extension/storage/mysql) and queue (platform/extension/messagequeue/mysql)
+		// both run on the same MySQL driver, so a single classifier covers
+		// errors surfaced from either backend.
+		mysqlerrs.Classifier,
+	}
+	if sqsimRuntime != nil {
+		classifiers = append(classifiers, model.Classifier)
+	}
 	primaryConsumer := consumer.New(logger.Sugar(), scope.SubScope("consumer"), registry,
-		errs.NewClassifierProcessor(
-			genericerrs.Classifier,
-			// Storage (submitqueue/extension/storage/mysql) and queue (platform/extension/messagequeue/mysql)
-			// both run on the same MySQL driver, so a single classifier covers
-			// errors surfaced from either backend.
-			mysqlerrs.Classifier,
-		),
+		errs.NewClassifierProcessor(classifiers...),
 	)
 	dlqConsumer := consumer.New(logger.Sugar(), scope.SubScope("consumer-dlq"), registry,
 		errs.AlwaysRetryableProcessor,
@@ -238,7 +249,8 @@ func run() error {
 	// back to a baseline profile for queues without an explicit entry. This is
 	// the single place queue topology is known; the extension packages stay
 	// queue-agnostic.
-	queues, err := newQueueRegistry(logger, scope, changeset.New(store.GetRequestStore(), store.GetChangeStore()))
+	resolver := changeset.New(store.GetRequestStore(), store.GetChangeStore())
+	queues, err := newQueueRegistry(logger, scope, resolver, sqsimRuntime)
 	if err != nil {
 		return fmt.Errorf("failed to build queue registry: %w", err)
 	}
@@ -893,7 +905,7 @@ const defaultPrioritizationLimit = 1000
 // conflict analyzer. Queues without an explicit profile fall back to the
 // baseline. This is the one place queue topology lives; extension packages stay
 // queue-agnostic.
-func newQueueRegistry(logger *zap.Logger, scope tally.Scope, resolver changeset.Resolver) (queueRegistry, error) {
+func newQueueRegistry(logger *zap.Logger, scope tally.Scope, resolver changeset.Resolver, sqsimRuntime *model.Runtime) (queueRegistry, error) {
 	cp, err := newChangeProvider(logger, scope)
 	if err != nil {
 		return queueRegistry{}, fmt.Errorf("failed to create change provider: %w", err)
@@ -969,13 +981,37 @@ func newQueueRegistry(logger *zap.Logger, scope tally.Scope, resolver changeset.
 	fileOverlapQueue := base
 	fileOverlapQueue.analyzer = fileoverlap.New(resolver)
 
+	// sqsim: maximum request-level parallelism for scenario and load runs. The
+	// modeled Build Runner is selected only when an explicit profile is loaded.
+	sqsimQueue := base
+	sqsimQueue.analyzer = none.New()
+	if sqsimRuntime != nil {
+		sqsimQueue.buildRunner = simbuildrunner.New(sqsimRuntime, resolver, "sqsim")
+	}
+
 	return queueRegistry{
 		def: base,
 		byQueue: map[string]queueExtensions{
 			"test-queue":               testQueue,
 			"e2e-test-queue":           e2eQueue,
 			"e2e-conflict-error-queue": conflictErrQueue,
 			"file-overlap-queue":       fileOverlapQueue,
+			"sqsim":                    sqsimQueue,
 		},
 	}, nil
 }
+
+func loadSQSimRuntime(path string) (*model.Runtime, error) {
+	if path == "" {
+		return nil, nil
+	}
+	profile, err := model.Load(path)
+	if err != nil {
+		return nil, fmt.Errorf("load SQSim profile: %w", err)
+	}
+	runtime, err := model.NewRuntime(profile, model.RealClock{})
+	if err != nil {
+		return nil, fmt.Errorf("initialize SQSim runtime: %w", err)
+	}
+	return runtime, nil
+}