@@ -5,6 +5,7 @@ go_library(
     srcs = [
         "batch.go",
         "buildsignal.go",
+        "dependencyanalysis.go",
         "dlq.go",
         "landconflictsignal.go",
         "landsignal.go",
@@ -37,6 +38,7 @@ go_test(
     srcs = [
         "batch_test.go",
         "buildsignal_test.go",
+        "dependencyanalysis_test.go",
         "dlq_test.go",
         "landconflictsignal_test.go",
         "landsignal_test.go",
 
@@ -31,9 +31,9 @@ Two controller shapes cover the eleven primary pipeline topics:
 | Controller | Topics | Decoded ID | Terminal state |
 |---|---|---|---|
 | `NewDLQRequestController` | `start`, `validate`, `batch`, `cancel`, `log` | `RequestID` | `RequestStateError` |
-| `NewDLQBatchController` | `speculate`, `build`, `land`, `conclude` | `BatchID` | `BatchStateFailed` + fan-out to member requests as `RequestStateError` |
+| `NewDLQBatchController` | `build`, `land`, `conclude` | `BatchID` | `BatchStateFailed` + fan-out to member requests as `RequestStateError` |
 
-`buildsignal` carries a `Build` payload and has its own small dedicated controller. The split exists because the DLQ message payload shape mirrors the primary topic's payload shape (the queue framework preserves bytes verbatim under the `_dlq` topic name), so the decoder is what changes per topic — not the reconciliation step. The package-level `RequestIDDecoder` interface plus `DecodeLandRequestID` / `DecodeCancelRequestID` / `DecodeRequestID` cover the three payload shapes used by request-scoped topics.
+`buildsignal` carries a `Build` payload and has its own small dedicated controller. `speculate` and `dependency-analysis` carry a `BatchID` but have dedicated controllers, because the batch on their message is not necessarily the one at fault: a speculate run re-plans the whole queue, and a dependency-analysis batch may be a duplicate whose requests another batch already carries. See the doc comments in `speculate.go` and `dependencyanalysis.go`. The split exists because the DLQ message payload shape mirrors the primary topic's payload shape (the queue framework preserves bytes verbatim under the `_dlq` topic name), so the decoder is what changes per topic — not the reconciliation step. The package-level `RequestIDDecoder` interface plus `DecodeLandRequestID` / `DecodeCancelRequestID` / `DecodeRequestID` cover the three payload shapes used by request-scoped topics.
 
 ## Idempotency and concurrent activity
 
 
@@ -0,0 +1,197 @@
+// 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 dlq
+
+import (
+	"context"
+	"errors"
+	"fmt"
+
+	"github.com/uber-go/tally"
+	entityqueue "github.com/uber/submitqueue/platform/base/messagequeue"
+	"github.com/uber/submitqueue/platform/consumer"
+	"github.com/uber/submitqueue/platform/metrics"
+	sqmq "github.com/uber/submitqueue/submitqueue/core/messagequeue"
+	"github.com/uber/submitqueue/submitqueue/entity"
+	"github.com/uber/submitqueue/submitqueue/extension/storage"
+	corebatch "github.com/uber/submitqueue/submitqueue/orchestrator/core/batch"
+	orchstorage "github.com/uber/submitqueue/submitqueue/orchestrator/extension/storage"
+	"go.uber.org/zap"
+)
+
+// dependencyAnalysisController is the DLQ reconciler for the dependency-analysis
+// topic.
+//
+// It does not share the generic batch reconciler because the batch on this
+// message need not own its requests. The batch stage mints a batch per
+// delivery, so one request can have several batches, and dependency analysis is
+// where one of them is chosen. The generic reconciler fails every member
+// request, so a dead-lettered duplicate would write Error over a request whose
+// chosen batch is still live, and that batch would go on to land it.
+//
+// So the batch's state decides:
+//
+//   - Creating, with a request already carried by another batch past Creating:
+//     a duplicate. Nothing is touched; it stays inert in Creating, as the
+//     primary controller leaves it.
+//   - Creating otherwise, Created, or Failed: this batch owns its requests and
+//     nothing downstream will advance it, so it is failed and fanned out.
+//   - Any later state: a downstream stage took the batch over after this message
+//     was written, and owns its outcome.
+type dependencyAnalysisController struct {
+	logger        *zap.SugaredLogger
+	metricsScope  tally.Scope
+	stores        orchstorage.Factory
+	registry      consumer.TopicRegistry
+	topicKey      consumer.TopicKey
+	consumerGroup string
+}
+
+// Verify dependencyAnalysisController implements consumer.Controller at compile time.
+var _ consumer.Controller = (*dependencyAnalysisController)(nil)
+
+// NewDLQDependencyAnalysisController builds the DLQ controller for the
+// dependency-analysis topic. topicKey must be the DLQ topic key (typically
+// TopicKey(primary)).
+func NewDLQDependencyAnalysisController(
+	logger *zap.SugaredLogger,
+	scope tally.Scope,
+	stores orchstorage.Factory,
+	registry consumer.TopicRegistry,
+	topicKey consumer.TopicKey,
+	consumerGroup string,
+) consumer.Controller {
+	name := string(topicKey) + "_controller"
+	return &dependencyAnalysisController{
+		logger:        logger.Named(name),
+		metricsScope:  scope.SubScope(name),
+		stores:        stores,
+		registry:      registry,
+		topicKey:      topicKey,
+		consumerGroup: consumerGroup,
+	}
+}
+
+// Process reconciles a single dead-lettered dependency-analysis message.
+func (c *dependencyAnalysisController) Process(ctx context.Context, delivery consumer.Delivery) error {
+	const opName = "process"
+
+	msg := delivery.Message()
+
+	bid, err := sqmq.UnmarshalBatchID(primaryTopicKey(c.topicKey), msg.Payload)
+	if err != nil {
+		metrics.NamedCounter(c.metricsScope, opName, "deserialize_errors", 1)
+		return fmt.Errorf("failed to decode batch id from dlq payload: %w", err)
+	}
+	if err := entityqueue.ValidatePayloadQueue(msg, bid.Queue); err != nil {
+		metrics.NamedCounter(c.metricsScope, opName, "queue_identity_errors", 1)
+		return nil
+	}
+	if bid.ID == "" {
+		metrics.NamedCounter(c.metricsScope, opName, "empty_id_errors", 1)
+		return fmt.Errorf("dlq payload decoded to empty batch id")
+	}
+
+	store, err := c.stores.For(orchstorage.Config{QueueName: bid.Queue})
+	if err != nil {
+		metrics.NamedCounter(c.metricsScope, opName, "storage_resolve_errors", 1)
+		// Non-retryable: a missing or unresolvable queue is a malformed message.
+		return fmt.Errorf("failed to resolve storage for queue %q: %w", bid.Queue, err)
+	}
+
+	lastError, failureMeta := failureContext(delivery)
+	dmeta := delivery.Metadata()
+	c.logger.Warnw("dlq message received",
+		"batch_id", bid.ID,
+		"attempt", delivery.Attempt(),
+		"dlq_original_topic", dmeta["dlq.original_topic"],
+		"dlq_failure_count", dmeta["dlq.failure_count"],
+		"dlq_last_error", dmeta["dlq.last_error"],
+	)
+
+	batch, err := store.GetBatchStore().Get(ctx, bid.ID)
+	if err != nil {
+		if errors.Is(err, storage.ErrNotFound) {
+			c.logger.Warnw("dlq reconcile: batch not found, skipping", "batch_id", bid.ID)
+			return nil
+		}
+		metrics.NamedCounter(c.metricsScope, opName, "storage_errors", 1)
+		return fmt.Errorf("failed to get batch %s: %w", bid.ID, err)
+	}
+
+	switch batch.State {
+	case entity.BatchStateCreating:
+		carrier, err := c.findOtherBatchCarryingRequests(ctx, store, batch)
+		if err != nil {
+			metrics.NamedCounter(c.metricsScope, opName, "batch_lookup_errors", 1)
+			return err
+		}
+		if carrier != "" {
+			metrics.NamedCounter(c.metricsScope, opName, "skipped_duplicate", 1)
+			c.logger.Infow("dlq reconcile: batch is a duplicate, its requests are carried by another",
+				"batch_id", batch.ID,
+				"carried_by", carrier,
+			)
+			return nil
+		}
+	case entity.BatchStateCreated, entity.BatchStateFailed:
+	default:
+		metrics.NamedCounter(c.metricsScope, opName, "skipped_owned_downstream", 1)
+		c.logger.Infow("dlq reconcile: batch has moved past dependency analysis, leaving it to its current stage",
+			"batch_id", batch.ID,
+			"state", string(batch.State),
+		)
+		return nil
+	}
+
+	if _, err := failBatch(ctx, store, c.registry, c.logger, batch.ID, lastError, failureMeta); err != nil {
+		metrics.NamedCounter(c.metricsScope, opName, "reconcile_errors", 1)
+		return err
+	}
+	return nil
+}
+
+// findOtherBatchCarryingRequests returns a batch other than this one that got
+// past Creating with one of this batch's requests, or the empty string. It is
+// the same test the primary controller uses to abandon a duplicate.
+func (c *dependencyAnalysisController) findOtherBatchCarryingRequests(ctx context.Context, store orchstorage.Storage, batch entity.Batch) (string, error) {
+	for _, requestID := range batch.Contains {
+		batches, _, err := corebatch.FindByRequestID(ctx, store, requestID)
+		if err != nil {
+			return "", err
+		}
+		for _, other := range batches {
+			if other.ID != batch.ID && other.State != entity.BatchStateCreating {
+				return other.ID, nil
+			}
+		}
+	}
+	return "", nil
+}
+
+// Name returns the controller name for logging and metrics.
+func (c *dependencyAnalysisController) Name() string {
+	return string(c.topicKey)
+}
+
+// TopicKey returns the topic key this controller subscribes to.
+func (c *dependencyAnalysisController) TopicKey() consumer.TopicKey {
+	return c.topicKey
+}
+
+// ConsumerGroup returns the consumer group for offset tracking.
+func (c *dependencyAnalysisController) ConsumerGroup() string {
+	return c.consumerGroup
+}