diff --git a/client/clientfactory.go b/client/clientfactory.go
new file mode 100644
index 00000000000..9c4f689716d
--- /dev/null
+++ b/client/clientfactory.go
@@ -0,0 +1,41 @@
+package client
+
+import (
+	"code.uber.internal/devexp/minions/client/history"
+	"code.uber.internal/devexp/minions/client/matching"
+	"code.uber.internal/devexp/minions/common/membership"
+	"code.uber.internal/devexp/minions/common/metrics"
+	tchannel "github.com/uber/tchannel-go"
+)
+
+// Factory can be used to create RPC clients for cadence services
+type Factory interface {
+	NewHistoryClient() (history.Client, error)
+	NewMatchingClient() (matching.Client, error)
+}
+
+type tchannelClientFactory struct {
+	ch                    *tchannel.Channel
+	monitor               membership.Monitor
+	metricsClient         metrics.Client
+	numberOfHistoryShards int
+}
+
+// NewTChannelClientFactory creates an instance of client factory using tchannel
+func NewTChannelClientFactory(ch *tchannel.Channel,
+	monitor membership.Monitor, metricsClient metrics.Client, numberOfHistoryShards int) Factory {
+	return &tchannelClientFactory{
+		ch:                    ch,
+		monitor:               monitor,
+		metricsClient:         metricsClient,
+		numberOfHistoryShards: numberOfHistoryShards,
+	}
+}
+
+func (cf *tchannelClientFactory) NewHistoryClient() (history.Client, error) {
+	return history.NewClient(cf.ch, cf.monitor, cf.numberOfHistoryShards)
+}
+
+func (cf *tchannelClientFactory) NewMatchingClient() (matching.Client, error) {
+	return matching.NewClient(cf.ch, cf.monitor)
+}
diff --git a/client/history/client.go b/client/history/client.go
index 5fec9ee4816..3f72c197cf4 100644
--- a/client/history/client.go
+++ b/client/history/client.go
@@ -1,6 +1,7 @@
 package history
 
 import (
+	"sync"
 	"time"
 
 	"golang.org/x/net/context"
@@ -8,53 +9,44 @@ import (
 	h "code.uber.internal/devexp/minions/.gen/go/history"
 	workflow "code.uber.internal/devexp/minions/.gen/go/shared"
 	"code.uber.internal/devexp/minions/common/membership"
+	"code.uber.internal/devexp/minions/common/util"
 	tchannel "github.com/uber/tchannel-go"
 	"github.com/uber/tchannel-go/thrift"
 )
 
 const historyServiceName = "cadence-history"
-const shardID = "1" // TODO: actually derive shardID from request
 
 var _ Client = (*clientImpl)(nil)
 
 type clientImpl struct {
-	connection *tchannel.Channel
-	resolver   membership.ServiceResolver
+	connection      *tchannel.Channel
+	resolver        membership.ServiceResolver
+	tokenSerializer util.TaskTokenSerializer
+	numberOfShards  int
+	// TODO: consider refactor thriftCache into a separate struct
+	thriftCacheLock sync.RWMutex
+	thriftCache     map[string]h.TChanHistoryService
 }
 
 // NewClient creates a new history service TChannel client
-func NewClient(ch *tchannel.Channel, monitor membership.Monitor) (Client, error) {
+func NewClient(ch *tchannel.Channel, monitor membership.Monitor, numberOfShards int) (Client, error) {
 	sResolver, err := monitor.GetResolver(historyServiceName)
 	if err != nil {
 		return nil, err
 	}
 
 	client := &clientImpl{
-		connection: ch,
-		resolver:   sResolver,
+		connection:      ch,
+		resolver:        sResolver,
+		tokenSerializer: util.NewJSONTaskTokenSerializer(),
+		numberOfShards:  numberOfShards,
+		thriftCache:     make(map[string]h.TChanHistoryService),
 	}
 	return client, nil
 }
 
-func (c *clientImpl) getHostForRequest(key string) (h.TChanHistoryService, error) {
-	host, err := c.resolver.Lookup(key)
-	if err != nil {
-		return nil, err
-	}
-	// TODO: build client cache
-	tClient := thrift.NewClient(c.connection, historyServiceName, &thrift.ClientOptions{
-		HostPort: host.GetAddress(),
-	})
-	return h.NewTChanHistoryServiceClient(tClient), nil
-}
-
-func (c *clientImpl) createContext() (thrift.Context, context.CancelFunc) {
-	// TODO: make timeout configurable
-	return thrift.NewContext(time.Second * 30)
-}
-
 func (c *clientImpl) StartWorkflowExecution(request *workflow.StartWorkflowExecutionRequest) (*workflow.StartWorkflowExecutionResponse, error) {
-	client, err := c.getHostForRequest(shardID)
+	client, err := c.getHostForRequest(request.GetWorkflowId())
 	if err != nil {
 		return nil, err
 	}
@@ -65,7 +57,7 @@ func (c *clientImpl) StartWorkflowExecution(request *workflow.StartWorkflowExecu
 
 func (c *clientImpl) GetWorkflowExecutionHistory(
 	request *workflow.GetWorkflowExecutionHistoryRequest) (*workflow.GetWorkflowExecutionHistoryResponse, error) {
-	client, err := c.getHostForRequest(shardID)
+	client, err := c.getHostForRequest(request.Execution.GetWorkflowId())
 	if err != nil {
 		return nil, err
 	}
@@ -75,7 +67,7 @@ func (c *clientImpl) GetWorkflowExecutionHistory(
 }
 
 func (c *clientImpl) RecordDecisionTaskStarted(request *h.RecordDecisionTaskStartedRequest) (*h.RecordDecisionTaskStartedResponse, error) {
-	client, err := c.getHostForRequest(shardID)
+	client, err := c.getHostForRequest(request.WorkflowExecution.GetWorkflowId())
 	if err != nil {
 		return nil, err
 	}
@@ -85,7 +77,7 @@ func (c *clientImpl) RecordDecisionTaskStarted(request *h.RecordDecisionTaskStar
 }
 
 func (c *clientImpl) RecordActivityTaskStarted(request *h.RecordActivityTaskStartedRequest) (*h.RecordActivityTaskStartedResponse, error) {
-	client, err := c.getHostForRequest(shardID)
+	client, err := c.getHostForRequest(request.WorkflowExecution.GetWorkflowId())
 	if err != nil {
 		return nil, err
 	}
@@ -95,7 +87,11 @@ func (c *clientImpl) RecordActivityTaskStarted(request *h.RecordActivityTaskStar
 }
 
 func (c *clientImpl) RespondDecisionTaskCompleted(request *workflow.RespondDecisionTaskCompletedRequest) error {
-	client, err := c.getHostForRequest(shardID)
+	taskToken, err := c.tokenSerializer.Deserialize(request.TaskToken)
+	if err != nil {
+		return err
+	}
+	client, err := c.getHostForRequest(taskToken.WorkflowID)
 	if err != nil {
 		return err
 	}
@@ -105,7 +101,11 @@ func (c *clientImpl) RespondDecisionTaskCompleted(request *workflow.RespondDecis
 }
 
 func (c *clientImpl) RespondActivityTaskCompleted(request *workflow.RespondActivityTaskCompletedRequest) error {
-	client, err := c.getHostForRequest(shardID)
+	taskToken, err := c.tokenSerializer.Deserialize(request.TaskToken)
+	if err != nil {
+		return err
+	}
+	client, err := c.getHostForRequest(taskToken.WorkflowID)
 	if err != nil {
 		return err
 	}
@@ -115,7 +115,11 @@ func (c *clientImpl) RespondActivityTaskCompleted(request *workflow.RespondActiv
 }
 
 func (c *clientImpl) RespondActivityTaskFailed(request *workflow.RespondActivityTaskFailedRequest) error {
-	client, err := c.getHostForRequest(shardID)
+	taskToken, err := c.tokenSerializer.Deserialize(request.TaskToken)
+	if err != nil {
+		return err
+	}
+	client, err := c.getHostForRequest(taskToken.WorkflowID)
 	if err != nil {
 		return err
 	}
@@ -125,7 +129,11 @@ func (c *clientImpl) RespondActivityTaskFailed(request *workflow.RespondActivity
 }
 
 func (c *clientImpl) RecordActivityTaskHeartbeat(request *workflow.RecordActivityTaskHeartbeatRequest) (*workflow.RecordActivityTaskHeartbeatResponse, error) {
-	client, err := c.getHostForRequest(shardID)
+	taskToken, err := c.tokenSerializer.Deserialize(request.TaskToken)
+	if err != nil {
+		return nil, err
+	}
+	client, err := c.getHostForRequest(taskToken.WorkflowID)
 	if err != nil {
 		return nil, err
 	}
@@ -133,3 +141,43 @@ func (c *clientImpl) RecordActivityTaskHeartbeat(request *workflow.RecordActivit
 	defer cancel()
 	return client.RecordActivityTaskHeartbeat(ctx, request)
 }
+
+func (c *clientImpl) getHostForRequest(workflowID string) (h.TChanHistoryService, error) {
+	key := util.WorkflowIDToHistoryShard(workflowID, c.numberOfShards)
+	host, err := c.resolver.Lookup(string(key))
+	if err != nil {
+		return nil, err
+	}
+
+	return c.getThriftClient(host.GetAddress()), nil
+}
+
+func (c *clientImpl) createContext() (thrift.Context, context.CancelFunc) {
+	// TODO: make timeout configurable
+	return thrift.NewContext(time.Second * 30)
+}
+
+func (c *clientImpl) getThriftClient(hostPort string) h.TChanHistoryService {
+	c.thriftCacheLock.RLock()
+	client, ok := c.thriftCache[hostPort]
+	c.thriftCacheLock.RUnlock()
+	if ok {
+		return client
+	}
+
+	c.thriftCacheLock.Lock()
+	defer c.thriftCacheLock.Unlock()
+
+	// check again if in the cache cause it might have been added
+	// before we acquired the lock
+	client, ok = c.thriftCache[hostPort]
+	if !ok {
+		tClient := thrift.NewClient(c.connection, historyServiceName, &thrift.ClientOptions{
+			HostPort: hostPort,
+		})
+
+		client = h.NewTChanHistoryServiceClient(tClient)
+		c.thriftCache[hostPort] = client
+	}
+	return client
+}
diff --git a/common/clientfactory.go b/common/clientfactory.go
deleted file mode 100644
index 763a6e2e22f..00000000000
--- a/common/clientfactory.go
+++ /dev/null
@@ -1,34 +0,0 @@
-package common
-
-import (
-	"code.uber.internal/devexp/minions/client/history"
-	"code.uber.internal/devexp/minions/client/matching"
-	"code.uber.internal/devexp/minions/common/membership"
-	tchannel "github.com/uber/tchannel-go"
-)
-
-// ClientFactory can be used to create RPC clients for cadence services
-type ClientFactory interface {
-	NewHistoryClient() (history.Client, error)
-	NewMatchingClient() (matching.Client, error)
-}
-
-type tchannelClientFactory struct {
-	ch      *tchannel.Channel
-	monitor membership.Monitor
-}
-
-func newTChannelClientFactory(ch *tchannel.Channel, monitor membership.Monitor) ClientFactory {
-	return &tchannelClientFactory{
-		ch:      ch,
-		monitor: monitor,
-	}
-}
-
-func (cf *tchannelClientFactory) NewHistoryClient() (history.Client, error) {
-	return history.NewClient(cf.ch, cf.monitor)
-}
-
-func (cf *tchannelClientFactory) NewMatchingClient() (matching.Client, error) {
-	return matching.NewClient(cf.ch, cf.monitor)
-}
diff --git a/common/service.go b/common/service.go
index c3594c672d9..848fd3d6cd4 100644
--- a/common/service.go
+++ b/common/service.go
@@ -6,6 +6,7 @@ import (
 	"os"
 	"time"
 
+	"code.uber.internal/devexp/minions/client"
 	"code.uber.internal/devexp/minions/common/logging"
 	"code.uber.internal/devexp/minions/common/membership"
 	"code.uber.internal/devexp/minions/common/metrics"
@@ -40,7 +41,8 @@ type serviceImpl struct {
 	rpSeedHosts            []string
 	membershipMonitor      membership.Monitor
 	tchannelFactory        TChannelFactory
-	clientFactory          ClientFactory
+	clientFactory          client.Factory
+	numberOfHistoryShards  int
 	logger                 bark.Logger
 	metricsScope           tally.Scope
 	runtimeMetricsReporter *metrics.RuntimeMetricsReporter
@@ -48,15 +50,18 @@ type serviceImpl struct {
 
 // NewService instantiates a ServiceInstance
 // TODO: have a better name for Service.
+// TODO: consider passing a config object if the parameter list gets too big
 // this is the object which holds all the common stuff
 // shared by all the services.
-func NewService(serviceName string, logger bark.Logger, scope tally.Scope, tchanFactory TChannelFactory, rpHosts []string) Service {
+func NewService(serviceName string, logger bark.Logger,
+	scope tally.Scope, tchanFactory TChannelFactory, rpHosts []string, numberOfHistoryShards int) Service {
 	sVice := &serviceImpl{
-		sName:           serviceName,
-		logger:          logger.WithField("Service", serviceName),
-		tchannelFactory: tchanFactory,
-		rpSeedHosts:     rpHosts,
-		metricsScope:    scope,
+		sName:                 serviceName,
+		logger:                logger.WithField("Service", serviceName),
+		tchannelFactory:       tchanFactory,
+		rpSeedHosts:           rpHosts,
+		metricsScope:          scope,
+		numberOfHistoryShards: numberOfHistoryShards,
 	}
 	sVice.runtimeMetricsReporter = metrics.NewRuntimeMetricsReporter(scope, time.Minute, sVice.logger)
 
@@ -126,7 +131,8 @@ func (h *serviceImpl) Start(thriftServices []thrift.TChanServer) {
 	}
 	h.hostInfo = hostInfo
 
-	h.clientFactory = newTChannelClientFactory(h.ch, h.membershipMonitor)
+	metricsClient := metrics.NewClient(h.metricsScope, h.getMetricsServiceIdx(h.sName))
+	h.clientFactory = client.NewTChannelClientFactory(h.ch, h.membershipMonitor, metricsClient, h.numberOfHistoryShards)
 
 	// The service is now started up
 	log.Info("service started")
@@ -161,7 +167,7 @@ func (h *serviceImpl) GetMetricsScope() tally.Scope {
 	return h.metricsScope
 }
 
-func (h *serviceImpl) GetClientFactory() ClientFactory {
+func (h *serviceImpl) GetClientFactory() client.Factory {
 	return h.clientFactory
 }
 
@@ -192,3 +198,9 @@ func (h *serviceImpl) bootstrapRingpop(rp *ringpop.Ringpop, rpHosts []string) er
 	_, err := rp.Bootstrap(bOptions)
 	return err
 }
+
+func (h *serviceImpl) getMetricsServiceIdx(serviceName string) metrics.ServiceIdx {
+	// for now we always use frontend for all metrics
+	// TODO: return proper index based on service name once per-service metrics are defined
+	return metrics.Frontend
+}
diff --git a/common/serviceinterfaces.go b/common/serviceinterfaces.go
index 931057060e9..58b108193c9 100644
--- a/common/serviceinterfaces.go
+++ b/common/serviceinterfaces.go
@@ -5,6 +5,7 @@ import (
 	"github.com/uber-go/tally"
 	"github.com/uber/tchannel-go/thrift"
 
+	"code.uber.internal/devexp/minions/client"
 	"code.uber.internal/devexp/minions/common/membership"
 )
 
@@ -24,7 +25,7 @@ type (
 
 		GetMetricsScope() tally.Scope
 
-		GetClientFactory() ClientFactory
+		GetClientFactory() client.Factory
 
 		GetMembershipMonitor() membership.Monitor
 
diff --git a/common/jsonTaskTokenSerializer.go b/common/util/jsonTaskTokenSerializer.go
similarity index 97%
rename from common/jsonTaskTokenSerializer.go
rename to common/util/jsonTaskTokenSerializer.go
index c3e21811d99..6e4040dbb45 100644
--- a/common/jsonTaskTokenSerializer.go
+++ b/common/util/jsonTaskTokenSerializer.go
@@ -1,4 +1,4 @@
-package common
+package util
 
 import "encoding/json"
 
diff --git a/common/taskTokenSerializerInterfaces.go b/common/util/taskTokenSerializerInterfaces.go
similarity index 95%
rename from common/taskTokenSerializerInterfaces.go
rename to common/util/taskTokenSerializerInterfaces.go
index 8c9357fa73f..53252204262 100644
--- a/common/taskTokenSerializerInterfaces.go
+++ b/common/util/taskTokenSerializerInterfaces.go
@@ -1,4 +1,4 @@
-package common
+package util
 
 type (
 	// TaskTokenSerializer serializes task tokens
diff --git a/common/util/util.go b/common/util/util.go
index c31aa85df9c..2bdf9d75744 100644
--- a/common/util/util.go
+++ b/common/util/util.go
@@ -4,6 +4,8 @@ import (
 	"sync"
 	"time"
 
+	farm "github.com/dgryski/go-farm"
+
 	workflow "code.uber.internal/devexp/minions/.gen/go/shared"
 	"code.uber.internal/devexp/minions/common/backoff"
 )
@@ -74,3 +76,9 @@ func IsPersistenceTransientError(err error) bool {
 
 	return false
 }
+
+// WorkflowIDToHistoryShard is used to map workflowID to a shardID
+func WorkflowIDToHistoryShard(workflowID string, numberOfShards int) int {
+	hash := farm.Fingerprint32([]byte(workflowID))
+	return int(hash % uint32(numberOfShards))
+}
diff --git a/host/integration_test.go b/host/integration_test.go
index 3879a3c3109..99fb4a7245f 100644
--- a/host/integration_test.go
+++ b/host/integration_test.go
@@ -48,6 +48,10 @@ var (
 	integration = flag.Bool("integration", true, "run integration tests")
 )
 
+const (
+	testNumberOfHistoryShards = 4
+)
+
 type (
 	integrationSuite struct {
 		host   Cadence
@@ -105,7 +109,9 @@ func (s *integrationSuite) SetupTest() {
 	options.SchemaDir = ".."
 	s.SetupWorkflowStoreWithOptions(options)
 
-	s.host = NewCadence(s.ShardMgr, s.WorkflowMgr, s.TaskMgr, s.logger)
+	s.setupShards()
+
+	s.host = NewCadence(s.ShardMgr, s.WorkflowMgr, s.TaskMgr, testNumberOfHistoryShards, s.logger)
 	s.host.Start()
 	s.engine, _ = frontend.NewClient(s.ch, s.host.FrontendAddress())
 }
@@ -719,3 +725,13 @@ func (s *integrationSuite) TestSequential_UserTimers() {
 	s.Nil(poller.pollAndProcessDecisionTask(true, false))
 	s.True(workflowComplete)
 }
+
+func (s *integrationSuite) setupShards() {
+	// shard 0 is always created, we create additional shards if needed
+	for shardID := 1; shardID < testNumberOfHistoryShards; shardID++ {
+		err := s.CreateShard(shardID, "", 0)
+		if err != nil {
+			s.logger.WithField("error", err).Fatal("Failed to create shard")
+		}
+	}
+}
diff --git a/host/onebox.go b/host/onebox.go
index 6b5e38a1037..21ef6157865 100644
--- a/host/onebox.go
+++ b/host/onebox.go
@@ -25,26 +25,28 @@ type Cadence interface {
 }
 
 type cadenceImpl struct {
-	frontendHandler *frontend.WorkflowHandler
-	matchingHandler *matching.Handler
-	historyHandler  *history.Handler
-	logger          bark.Logger
-	shardMgr        persistence.ShardManager
-	taskMgr         persistence.TaskManager
-	executionMgr    persistence.ExecutionManager
-	shutdownCh      chan struct{}
-	shutdownWG      sync.WaitGroup
+	frontendHandler       *frontend.WorkflowHandler
+	matchingHandler       *matching.Handler
+	historyHandler        *history.Handler
+	numberOfHistoryShards int
+	logger                bark.Logger
+	shardMgr              persistence.ShardManager
+	taskMgr               persistence.TaskManager
+	executionMgr          persistence.ExecutionManager
+	shutdownCh            chan struct{}
+	shutdownWG            sync.WaitGroup
 }
 
 // NewCadence returns an instance that hosts full cadence in one process
 func NewCadence(shardMgr persistence.ShardManager, executionMgr persistence.ExecutionManager,
-	taskMgr persistence.TaskManager, logger bark.Logger) Cadence {
+	taskMgr persistence.TaskManager, numberOfHistoryShards int, logger bark.Logger) Cadence {
 	return &cadenceImpl{
-		logger:       logger,
-		shardMgr:     shardMgr,
-		taskMgr:      taskMgr,
-		executionMgr: executionMgr,
-		shutdownCh:   make(chan struct{}),
+		numberOfHistoryShards: numberOfHistoryShards,
+		logger:                logger,
+		shardMgr:              shardMgr,
+		taskMgr:               taskMgr,
+		executionMgr:          executionMgr,
+		shutdownCh:            make(chan struct{}),
 	}
 }
 
@@ -95,7 +97,7 @@ func (c *cadenceImpl) startFrontend(logger bark.Logger, rpHosts []string, startW
 		return c.createTChannel(sName, c.FrontendAddress(), thriftServices)
 	}
 	scope := tally.NewTestScope("cadence-frontend", make(map[string]string))
-	service := common.NewService("cadence-frontend", logger, scope, tchanFactory, rpHosts)
+	service := common.NewService("cadence-frontend", logger, scope, tchanFactory, rpHosts, c.numberOfHistoryShards)
 	var thriftServices []thrift.TChanServer
 	c.frontendHandler, thriftServices = frontend.NewWorkflowHandler(service)
 	err := c.frontendHandler.Start(thriftServices)
@@ -113,9 +115,9 @@ func (c *cadenceImpl) startHistory(logger bark.Logger, shardMgr persistence.Shar
 		return c.createTChannel(sName, c.HistoryServiceAddress(), thriftServices)
 	}
 	scope := tally.NewTestScope("cadence-history", make(map[string]string))
-	service := common.NewService("cadence-history", logger, scope, tchanFactory, rpHosts)
+	service := common.NewService("cadence-history", logger, scope, tchanFactory, rpHosts, c.numberOfHistoryShards)
 	var thriftServices []thrift.TChanServer
-	c.historyHandler, thriftServices = history.NewHandler(service, shardMgr, executionMgr)
+	c.historyHandler, thriftServices = history.NewHandler(service, shardMgr, executionMgr, c.numberOfHistoryShards)
 	c.historyHandler.Start(thriftServices)
 	startWG.Done()
 	<-c.shutdownCh
@@ -128,7 +130,7 @@ func (c *cadenceImpl) startMatching(logger bark.Logger, taskMgr persistence.Task
 		return c.createTChannel(sName, c.MatchingServiceAddress(), thriftServices)
 	}
 	scope := tally.NewTestScope("cadence-matching", make(map[string]string))
-	service := common.NewService("cadence-matching", logger, scope, tchanFactory, rpHosts)
+	service := common.NewService("cadence-matching", logger, scope, tchanFactory, rpHosts, c.numberOfHistoryShards)
 	var thriftServices []thrift.TChanServer
 	c.matchingHandler, thriftServices = matching.NewHandler(taskMgr, service)
 	c.matchingHandler.Start(thriftServices)
diff --git a/service/history/handler.go b/service/history/handler.go
index efaee151cf7..d0e9b2c808d 100644
--- a/service/history/handler.go
+++ b/service/history/handler.go
@@ -8,14 +8,10 @@ import (
 	"code.uber.internal/devexp/minions/client/matching"
 	"code.uber.internal/devexp/minions/common"
 	"code.uber.internal/devexp/minions/common/persistence"
+	"code.uber.internal/devexp/minions/common/util"
 	"github.com/uber/tchannel-go/thrift"
 )
 
-const (
-	// TODO: Move this to config knob
-	numberOfShards = 1
-)
-
 // Handler - Thrift handler inteface for history service
 type Handler struct {
 	numberOfShards        int
@@ -23,7 +19,7 @@ type Handler struct {
 	executionManager      persistence.ExecutionManager
 	matchingServiceClient matching.Client
 	controller            *shardController
-	tokenSerializer       common.TaskTokenSerializer
+	tokenSerializer       util.TaskTokenSerializer
 	common.Service
 }
 
@@ -32,13 +28,13 @@ var _ EngineFactory = (*Handler)(nil)
 
 // NewHandler creates a thrift handler for the history service
 func NewHandler(sVice common.Service, shardManager persistence.ShardManager,
-	executionPersistence persistence.ExecutionManager) (*Handler, []thrift.TChanServer) {
+	executionPersistence persistence.ExecutionManager, numberOfShards int) (*Handler, []thrift.TChanServer) {
 	handler := &Handler{
 		Service:          sVice,
 		shardManager:     shardManager,
 		executionManager: executionPersistence,
 		numberOfShards:   numberOfShards,
-		tokenSerializer:  common.NewJSONTaskTokenSerializer(),
+		tokenSerializer:  util.NewJSONTaskTokenSerializer(),
 	}
 	return handler, []thrift.TChanServer{h.NewTChanHistoryServiceServer(handler)}
 }
diff --git a/service/history/historyEngine.go b/service/history/historyEngine.go
index 13a68e29bab..9a431971544 100644
--- a/service/history/historyEngine.go
+++ b/service/history/historyEngine.go
@@ -22,7 +22,7 @@ type (
 		executionManager persistence.ExecutionManager
 		txProcessor      transferQueueProcessor
 		timerProcessor   timerQueueProcessor
-		tokenSerializer  common.TaskTokenSerializer
+		tokenSerializer  util.TaskTokenSerializer
 		tracker          *pendingTaskTracker
 		logger           bark.Logger
 	}
@@ -89,7 +89,7 @@ func NewEngineWithShardContext(shard ShardContext, executionManager persistence.
 		shard:            shard,
 		executionManager: executionManager,
 		txProcessor:      txProcessor,
-		tokenSerializer:  common.NewJSONTaskTokenSerializer(),
+		tokenSerializer:  util.NewJSONTaskTokenSerializer(),
 		tracker:          tracker,
 		logger: logger.WithFields(bark.Fields{
 			tagWorkflowComponent: tagValueWorkflowEngineComponent,
diff --git a/service/history/historyEngine_test.go b/service/history/historyEngine_test.go
index 8308fb135d9..dc3435e533d 100644
--- a/service/history/historyEngine_test.go
+++ b/service/history/historyEngine_test.go
@@ -16,6 +16,7 @@ import (
 	"code.uber.internal/devexp/minions/common"
 	"code.uber.internal/devexp/minions/common/mocks"
 	"code.uber.internal/devexp/minions/common/persistence"
+	"code.uber.internal/devexp/minions/common/util"
 )
 
 type (
@@ -66,7 +67,7 @@ func (s *engineSuite) SetupTest() {
 		txProcessor:      txProcessor,
 		tracker:          tracker,
 		logger:           s.logger,
-		tokenSerializer:  common.NewJSONTaskTokenSerializer(),
+		tokenSerializer:  util.NewJSONTaskTokenSerializer(),
 	}
 	h.timerProcessor = newTimerQueueProcessor(h, s.mockExecutionMgr, s.logger)
 	s.mockHistoryEngine = h
@@ -93,7 +94,7 @@ func (s *engineSuite) TestRespondDecisionTaskCompletedInvalidToken() {
 }
 
 func (s *engineSuite) TestRespondDecisionTaskCompletedIfNoExecution() {
-	taskToken, _ := json.Marshal(&common.TaskToken{
+	taskToken, _ := json.Marshal(&util.TaskToken{
 		WorkflowID: "wId",
 		RunID:      "rId",
 		ScheduleID: 2,
@@ -111,7 +112,7 @@ func (s *engineSuite) TestRespondDecisionTaskCompletedIfNoExecution() {
 }
 
 func (s *engineSuite) TestRespondDecisionTaskCompletedIfGetExecutionFailed() {
-	taskToken, _ := json.Marshal(&common.TaskToken{
+	taskToken, _ := json.Marshal(&util.TaskToken{
 		WorkflowID: "wId",
 		RunID:      "rId",
 		ScheduleID: 2,
@@ -129,7 +130,7 @@ func (s *engineSuite) TestRespondDecisionTaskCompletedIfGetExecutionFailed() {
 
 func (s *engineSuite) TestRespondDecisionTaskCompletedUpdateExecutionFailed() {
 	tl := "testTaskList"
-	taskToken, _ := json.Marshal(&common.TaskToken{
+	taskToken, _ := json.Marshal(&util.TaskToken{
 		WorkflowID: "wId",
 		RunID:      "rId",
 		ScheduleID: 2,
@@ -170,7 +171,7 @@ func (s *engineSuite) TestRespondDecisionTaskCompletedUpdateExecutionFailed() {
 
 func (s *engineSuite) TestRespondDecisionTaskCompletedIfTaskCompleted() {
 	tl := "testTaskList"
-	taskToken, _ := json.Marshal(&common.TaskToken{
+	taskToken, _ := json.Marshal(&util.TaskToken{
 		WorkflowID: "wId",
 		RunID:      "rId",
 		ScheduleID: 2,
@@ -211,7 +212,7 @@ func (s *engineSuite) TestRespondDecisionTaskCompletedIfTaskCompleted() {
 
 func (s *engineSuite) TestRespondDecisionTaskCompletedIfTaskNotStarted() {
 	tl := "testTaskList"
-	taskToken, _ := json.Marshal(&common.TaskToken{
+	taskToken, _ := json.Marshal(&util.TaskToken{
 		WorkflowID: "wId",
 		RunID:      "rId",
 		ScheduleID: 2,
@@ -273,7 +274,7 @@ func (s *engineSuite) TestRespondDecisionTaskCompletedConflictOnUpdate() {
 	decisionScheduledEvent2 := addDecisionTaskScheduledEvent(builder, tl, 30)
 	decisionStartedEvent2 := addDecisionTaskStartedEvent(builder, decisionScheduledEvent2.GetEventId(), tl, identity)
 
-	taskToken, _ := json.Marshal(&common.TaskToken{
+	taskToken, _ := json.Marshal(&util.TaskToken{
 		WorkflowID: "wId",
 		RunID:      "rId",
 		ScheduleID: decisionScheduledEvent2.GetEventId(),
@@ -353,7 +354,7 @@ func (s *engineSuite) TestRespondDecisionTaskCompletedConflictOnUpdate() {
 
 func (s *engineSuite) TestRespondDecisionTaskCompletedMaxAttemptsExceeded() {
 	tl := "testTaskList"
-	taskToken, _ := json.Marshal(&common.TaskToken{
+	taskToken, _ := json.Marshal(&util.TaskToken{
 		WorkflowID: "wId",
 		RunID:      "rId",
 		ScheduleID: 2,
@@ -433,7 +434,7 @@ func (s *engineSuite) TestRespondDecisionTaskCompletedCompleteWorkflowFailed() {
 	decisionScheduledEvent2 := addDecisionTaskScheduledEvent(builder, tl, 30)
 	decisionStartedEvent2 := addDecisionTaskStartedEvent(builder, decisionScheduledEvent2.GetEventId(), tl, identity)
 
-	taskToken, _ := json.Marshal(&common.TaskToken{
+	taskToken, _ := json.Marshal(&util.TaskToken{
 		WorkflowID: "wId",
 		RunID:      "rId",
 		ScheduleID: decisionScheduledEvent2.GetEventId(),
@@ -513,7 +514,7 @@ func (s *engineSuite) TestRespondDecisionTaskCompletedFailWorkflowFailed() {
 	decisionScheduledEvent2 := addDecisionTaskScheduledEvent(builder, tl, 30)
 	decisionStartedEvent2 := addDecisionTaskStartedEvent(builder, decisionScheduledEvent2.GetEventId(), tl, identity)
 
-	taskToken, _ := json.Marshal(&common.TaskToken{
+	taskToken, _ := json.Marshal(&util.TaskToken{
 		WorkflowID: "wId",
 		RunID:      "rId",
 		ScheduleID: decisionScheduledEvent2.GetEventId(),
@@ -565,7 +566,7 @@ func (s *engineSuite) TestRespondDecisionTaskCompletedFailWorkflowFailed() {
 
 func (s *engineSuite) TestRespondDecisionTaskCompletedSingleActivityScheduledDecision() {
 	tl := "testTaskList"
-	taskToken, _ := json.Marshal(&common.TaskToken{
+	taskToken, _ := json.Marshal(&util.TaskToken{
 		WorkflowID: "wId",
 		RunID:      "rId",
 		ScheduleID: 2,
@@ -637,7 +638,7 @@ func (s *engineSuite) TestRespondDecisionTaskCompletedSingleActivityScheduledDec
 
 func (s *engineSuite) TestRespondDecisionTaskCompletedCompleteWorkflowSuccess() {
 	tl := "testTaskList"
-	taskToken, _ := json.Marshal(&common.TaskToken{
+	taskToken, _ := json.Marshal(&util.TaskToken{
 		WorkflowID: "wId",
 		RunID:      "rId",
 		ScheduleID: 2,
@@ -696,7 +697,7 @@ func (s *engineSuite) TestRespondDecisionTaskCompletedCompleteWorkflowSuccess()
 
 func (s *engineSuite) TestRespondDecisionTaskCompletedFailWorkflowSuccess() {
 	tl := "testTaskList"
-	taskToken, _ := json.Marshal(&common.TaskToken{
+	taskToken, _ := json.Marshal(&util.TaskToken{
 		WorkflowID: "wId",
 		RunID:      "rId",
 		ScheduleID: 2,
@@ -771,7 +772,7 @@ func (s *engineSuite) TestRespondActivityTaskCompletedInvalidToken() {
 }
 
 func (s *engineSuite) TestRespondActivityTaskCompletedIfNoExecution() {
-	taskToken, _ := json.Marshal(&common.TaskToken{
+	taskToken, _ := json.Marshal(&util.TaskToken{
 		WorkflowID: "wId",
 		RunID:      "rId",
 		ScheduleID: 2,
@@ -789,7 +790,7 @@ func (s *engineSuite) TestRespondActivityTaskCompletedIfNoExecution() {
 }
 
 func (s *engineSuite) TestRespondActivityTaskCompletedIfGetExecutionFailed() {
-	taskToken, _ := json.Marshal(&common.TaskToken{
+	taskToken, _ := json.Marshal(&util.TaskToken{
 		WorkflowID: "wId",
 		RunID:      "rId",
 		ScheduleID: 2,
@@ -807,7 +808,7 @@ func (s *engineSuite) TestRespondActivityTaskCompletedIfGetExecutionFailed() {
 
 func (s *engineSuite) TestRespondActivityTaskCompletedUpdateExecutionFailed() {
 	tl := "testTaskList"
-	taskToken, _ := json.Marshal(&common.TaskToken{
+	taskToken, _ := json.Marshal(&util.TaskToken{
 		WorkflowID: "wId",
 		RunID:      "rId",
 		ScheduleID: 5,
@@ -849,7 +850,7 @@ func (s *engineSuite) TestRespondActivityTaskCompletedUpdateExecutionFailed() {
 
 func (s *engineSuite) TestRespondActivityTaskCompletedIfTaskCompleted() {
 	tl := "testTaskList"
-	taskToken, _ := json.Marshal(&common.TaskToken{
+	taskToken, _ := json.Marshal(&util.TaskToken{
 		WorkflowID: "wId",
 		RunID:      "rId",
 		ScheduleID: 5,
@@ -894,7 +895,7 @@ func (s *engineSuite) TestRespondActivityTaskCompletedIfTaskCompleted() {
 
 func (s *engineSuite) TestRespondActivityTaskCompletedIfTaskNotStarted() {
 	tl := "testTaskList"
-	taskToken, _ := json.Marshal(&common.TaskToken{
+	taskToken, _ := json.Marshal(&util.TaskToken{
 		WorkflowID: "wId",
 		RunID:      "rId",
 		ScheduleID: 5,
@@ -934,7 +935,7 @@ func (s *engineSuite) TestRespondActivityTaskCompletedIfTaskNotStarted() {
 
 func (s *engineSuite) TestRespondActivityTaskCompletedConflictOnUpdate() {
 	tl := "testTaskList"
-	taskToken, _ := json.Marshal(&common.TaskToken{
+	taskToken, _ := json.Marshal(&util.TaskToken{
 		WorkflowID: "wId",
 		RunID:      "rId",
 		ScheduleID: 5,
@@ -1008,7 +1009,7 @@ func (s *engineSuite) TestRespondActivityTaskCompletedConflictOnUpdate() {
 
 func (s *engineSuite) TestRespondActivityTaskCompletedMaxAttemptsExceeded() {
 	tl := "testTaskList"
-	taskToken, _ := json.Marshal(&common.TaskToken{
+	taskToken, _ := json.Marshal(&util.TaskToken{
 		WorkflowID: "wId",
 		RunID:      "rId",
 		ScheduleID: 5,
@@ -1051,7 +1052,7 @@ func (s *engineSuite) TestRespondActivityTaskCompletedMaxAttemptsExceeded() {
 
 func (s *engineSuite) TestRespondActivityTaskCompletedSuccess() {
 	tl := "testTaskList"
-	taskToken, _ := json.Marshal(&common.TaskToken{
+	taskToken, _ := json.Marshal(&util.TaskToken{
 		WorkflowID: "wId",
 		RunID:      "rId",
 		ScheduleID: 5,
@@ -1123,7 +1124,7 @@ func (s *engineSuite) TestRespondActivityTaskFailedInvalidToken() {
 }
 
 func (s *engineSuite) TestRespondActivityTaskFailedIfNoExecution() {
-	taskToken, _ := json.Marshal(&common.TaskToken{
+	taskToken, _ := json.Marshal(&util.TaskToken{
 		WorkflowID: "wId",
 		RunID:      "rId",
 		ScheduleID: 2,
@@ -1141,7 +1142,7 @@ func (s *engineSuite) TestRespondActivityTaskFailedIfNoExecution() {
 }
 
 func (s *engineSuite) TestRespondActivityTaskFailedIfGetExecutionFailed() {
-	taskToken, _ := json.Marshal(&common.TaskToken{
+	taskToken, _ := json.Marshal(&util.TaskToken{
 		WorkflowID: "wId",
 		RunID:      "rId",
 		ScheduleID: 2,
@@ -1159,7 +1160,7 @@ func (s *engineSuite) TestRespondActivityTaskFailedIfGetExecutionFailed() {
 
 func (s *engineSuite) TestRespondActivityTaskFailedUpdateExecutionFailed() {
 	tl := "testTaskList"
-	taskToken, _ := json.Marshal(&common.TaskToken{
+	taskToken, _ := json.Marshal(&util.TaskToken{
 		WorkflowID: "wId",
 		RunID:      "rId",
 		ScheduleID: 5,
@@ -1200,7 +1201,7 @@ func (s *engineSuite) TestRespondActivityTaskFailedUpdateExecutionFailed() {
 
 func (s *engineSuite) TestRespondActivityTaskFailedIfTaskCompleted() {
 	tl := "testTaskList"
-	taskToken, _ := json.Marshal(&common.TaskToken{
+	taskToken, _ := json.Marshal(&util.TaskToken{
 		WorkflowID: "wId",
 		RunID:      "rId",
 		ScheduleID: 5,
@@ -1247,7 +1248,7 @@ func (s *engineSuite) TestRespondActivityTaskFailedIfTaskCompleted() {
 
 func (s *engineSuite) TestRespondActivityTaskFailedIfTaskNotStarted() {
 	tl := "testTaskList"
-	taskToken, _ := json.Marshal(&common.TaskToken{
+	taskToken, _ := json.Marshal(&util.TaskToken{
 		WorkflowID: "wId",
 		RunID:      "rId",
 		ScheduleID: 5,
@@ -1285,7 +1286,7 @@ func (s *engineSuite) TestRespondActivityTaskFailedIfTaskNotStarted() {
 
 func (s *engineSuite) TestRespondActivityTaskFailedConflictOnUpdate() {
 	tl := "testTaskList"
-	taskToken, _ := json.Marshal(&common.TaskToken{
+	taskToken, _ := json.Marshal(&util.TaskToken{
 		WorkflowID: "wId",
 		RunID:      "rId",
 		ScheduleID: 5,
@@ -1362,7 +1363,7 @@ func (s *engineSuite) TestRespondActivityTaskFailedConflictOnUpdate() {
 
 func (s *engineSuite) TestRespondActivityTaskFailedMaxAttemptsExceeded() {
 	tl := "testTaskList"
-	taskToken, _ := json.Marshal(&common.TaskToken{
+	taskToken, _ := json.Marshal(&util.TaskToken{
 		WorkflowID: "wId",
 		RunID:      "rId",
 		ScheduleID: 5,
@@ -1403,7 +1404,7 @@ func (s *engineSuite) TestRespondActivityTaskFailedMaxAttemptsExceeded() {
 
 func (s *engineSuite) TestRespondActivityTaskFailedSuccess() {
 	tl := "testTaskList"
-	taskToken, _ := json.Marshal(&common.TaskToken{
+	taskToken, _ := json.Marshal(&util.TaskToken{
 		WorkflowID: "wId",
 		RunID:      "rId",
 		ScheduleID: 5,
@@ -1466,7 +1467,7 @@ func (s *engineSuite) TestRespondActivityTaskFailedSuccess() {
 
 func (s *engineSuite) TestRecordActivityTaskHeartBeatSuccess_NoTimer() {
 	tl := "testTaskList"
-	taskToken, _ := json.Marshal(&common.TaskToken{
+	taskToken, _ := json.Marshal(&util.TaskToken{
 		WorkflowID: "wId",
 		RunID:      "rId",
 		ScheduleID: 5,
@@ -1501,7 +1502,7 @@ func (s *engineSuite) TestRecordActivityTaskHeartBeatSuccess_NoTimer() {
 
 func (s *engineSuite) TestRecordActivityTaskHeartBeatSuccess_TimerRunning() {
 	tl := "testTaskList"
-	taskToken, _ := json.Marshal(&common.TaskToken{
+	taskToken, _ := json.Marshal(&util.TaskToken{
 		WorkflowID: "wId",
 		RunID:      "rId",
 		ScheduleID: 5,
diff --git a/service/history/shardController.go b/service/history/shardController.go
index cd934a28330..70f7c23c5ad 100644
--- a/service/history/shardController.go
+++ b/service/history/shardController.go
@@ -6,7 +6,6 @@ import (
 	"sync/atomic"
 	"time"
 
-	"github.com/dgryski/go-farm"
 	"github.com/uber-common/bark"
 
 	"code.uber.internal/devexp/minions/common/membership"
@@ -111,7 +110,7 @@ func (c *shardController) Stop() {
 }
 
 func (c *shardController) GetEngine(workflowID string) (Engine, error) {
-	shardID := WorkflowIDToShard(workflowID)
+	shardID := util.WorkflowIDToHistoryShard(workflowID, c.numberOfShards)
 	return c.getEngineForShard(shardID)
 }
 
@@ -268,9 +267,3 @@ func (i *historyShardsItem) stopEngine() {
 		i.engine.Stop()
 	}
 }
-
-// WorkflowIDToShard is used to hash workflowID to a shardID
-func WorkflowIDToShard(workflowID string) int {
-	hash := farm.Fingerprint32([]byte(workflowID))
-	return int(hash % numberOfShards)
-}
diff --git a/service/history/timerQueueProcessor_test.go b/service/history/timerQueueProcessor_test.go
index 5543a885b06..a3a6999ea60 100644
--- a/service/history/timerQueueProcessor_test.go
+++ b/service/history/timerQueueProcessor_test.go
@@ -9,6 +9,7 @@ import (
 	"code.uber.internal/devexp/minions/common"
 	"code.uber.internal/devexp/minions/common/mocks"
 	"code.uber.internal/devexp/minions/common/persistence"
+	"code.uber.internal/devexp/minions/common/util"
 
 	workflow "code.uber.internal/devexp/minions/.gen/go/shared"
 	log "github.com/Sirupsen/logrus"
@@ -57,7 +58,7 @@ func (s *timerQueueProcessorSuite) SetupSuite() {
 		txProcessor:      txProcessor,
 		logger:           s.logger,
 		tracker:          tracker,
-		tokenSerializer:  common.NewJSONTaskTokenSerializer(),
+		tokenSerializer:  util.NewJSONTaskTokenSerializer(),
 	}
 }
 
diff --git a/service/matching/matchingEngine.go b/service/matching/matchingEngine.go
index 3576a814318..4e98aaa31c5 100644
--- a/service/matching/matchingEngine.go
+++ b/service/matching/matchingEngine.go
@@ -24,7 +24,7 @@ const defaultRangeSize = 100000
 type matchingEngineImpl struct {
 	taskManager     persistence.TaskManager
 	historyService  history.Client
-	tokenSerializer common.TaskTokenSerializer
+	tokenSerializer util.TaskTokenSerializer
 	taskLists       map[taskListID]*taskListContext
 	rangeSize       int64
 	logger          bark.Logger
@@ -81,7 +81,7 @@ func NewEngine(taskManager persistence.TaskManager, historyService history.Clien
 	return &matchingEngineImpl{
 		taskManager:     taskManager,
 		historyService:  historyService,
-		tokenSerializer: common.NewJSONTaskTokenSerializer(),
+		tokenSerializer: util.NewJSONTaskTokenSerializer(),
 		taskLists:       make(map[taskListID]*taskListContext),
 		rangeSize:       defaultRangeSize,
 		logger: logger.WithFields(bark.Fields{
@@ -327,7 +327,7 @@ func (e *matchingEngineImpl) createPollForDecisionTaskResponse(context *taskCont
 
 	response := workflow.NewPollForDecisionTaskResponse()
 	response.WorkflowExecution = workflowExecutionPtr(context.workflowExecution)
-	token := &common.TaskToken{
+	token := &util.TaskToken{
 		WorkflowID: task.WorkflowID,
 		RunID:      task.RunID,
 		ScheduleID: task.ScheduleID,
@@ -359,7 +359,7 @@ func (e *matchingEngineImpl) createPollForActivityTaskResponse(context *taskCont
 	response.StartedEventId = common.Int64Ptr(startedEvent.GetEventId())
 	response.WorkflowExecution = workflowExecutionPtr(context.workflowExecution)
 
-	token := &common.TaskToken{
+	token := &util.TaskToken{
 		WorkflowID: task.WorkflowID,
 		RunID:      task.RunID,
 		ScheduleID: task.ScheduleID,
diff --git a/service/matching/matchingEngine_test.go b/service/matching/matchingEngine_test.go
index eef25c944c8..3ef60b3e565 100644
--- a/service/matching/matchingEngine_test.go
+++ b/service/matching/matchingEngine_test.go
@@ -19,6 +19,7 @@ import (
 	"code.uber.internal/devexp/minions/common"
 	"code.uber.internal/devexp/minions/common/mocks"
 	"code.uber.internal/devexp/minions/common/persistence"
+	"code.uber.internal/devexp/minions/common/util"
 )
 
 type (
@@ -56,7 +57,7 @@ func (s *matchingEngineSuite) SetupTest() {
 		historyService:  s.historyClient,
 		taskLists:       make(map[taskListID]*taskListContext),
 		logger:          s.logger,
-		tokenSerializer: common.NewJSONTaskTokenSerializer(),
+		tokenSerializer: util.NewJSONTaskTokenSerializer(),
 	}
 }
 
@@ -167,7 +168,7 @@ func (s *matchingEngineSuite) TestPollForActivityTasks() {
 		s.EqualValues(activityInput, result.Input)
 		s.EqualValues(startedID, *result.StartedEventId)
 		s.EqualValues(workflowExecution, result.WorkflowExecution)
-		token := &common.TaskToken{
+		token := &util.TaskToken{
 			WorkflowID: workflowID,
 			RunID:      runID,
 			ScheduleID: scheduleID,