diff --git a/pkg/apis/flyteworkflow/v1alpha1/iface.go b/pkg/apis/flyteworkflow/v1alpha1/iface.go
index 26cfd2321..1ceddd36f 100644
--- a/pkg/apis/flyteworkflow/v1alpha1/iface.go
+++ b/pkg/apis/flyteworkflow/v1alpha1/iface.go
@@ -236,8 +236,8 @@ type MutableDynamicNodeStatus interface {
 	SetExecutionError(executionError *core.ExecutionError)
 }
 
-// Interface for Branch node. All the methods are purely read only except for the GetExecutionStatus.
-// p returns ExecutableBranchNodeStatus, which permits some mutations
+// ExecutableBranchNode is an interface for Branch node. All the methods are purely read only except for the
+// GetExecutionStatus. p returns ExecutableBranchNodeStatus, which permits some mutations
 type ExecutableBranchNode interface {
 	GetIf() ExecutableIfBlock
 	GetElse() *NodeID
@@ -443,6 +443,7 @@ type Meta interface {
 	GetSecurityContext() core.SecurityContext
 	IsInterruptible() bool
 	GetEventVersion() EventVersion
+	GetDefinitionVersion() WorkflowDefinitionVersion
 	GetRawOutputDataConfig() RawOutputDataConfig
 }
 
diff --git a/pkg/apis/flyteworkflow/v1alpha1/workflow.go b/pkg/apis/flyteworkflow/v1alpha1/workflow.go
index d96a87d14..11e73a167 100644
--- a/pkg/apis/flyteworkflow/v1alpha1/workflow.go
+++ b/pkg/apis/flyteworkflow/v1alpha1/workflow.go
@@ -23,6 +23,15 @@ const ShardKeyspaceSize = 32
 const StartNodeID = "start-node"
 const EndNodeID = "end-node"
 
+type WorkflowDefinitionVersion uint32
+
+var LatestWorkflowDefinitionVersion = WorkflowDefinitionVersion1
+
+const (
+	WorkflowDefinitionVersion0 WorkflowDefinitionVersion = iota
+	WorkflowDefinitionVersion1
+)
+
 // +genclient
 // +k8s:deepcopy-gen:interfaces=k8s.io/apimachinery/pkg/runtime.Object
 
@@ -82,12 +91,25 @@ func (in *FlyteWorkflow) GetEventVersion() EventVersion {
 	return EventVersion0
 }
 
+func (in *FlyteWorkflow) GetDefinitionVersion() WorkflowDefinitionVersion {
+	if meta := in.WorkflowMeta; meta != nil && meta.DefinitionVersion != nil {
+		return *meta.DefinitionVersion
+	}
+
+	return WorkflowDefinitionVersion0
+}
+
 func (in *FlyteWorkflow) GetExecutionConfig() ExecutionConfig {
 	return in.ExecutionConfig
 }
 
 type WorkflowMeta struct {
 	EventVersion EventVersion `json:"eventVersion,omitempty"`
+	// DefinitionVersion allows propeller code that populates the CRD to evolve (in backward incompatible ways) without
+	// affecting in-flight executions. Once an execution starts, propeller will populate this field with the current or
+	// latest version. If a newer propeller version is deployed midway that comes with a newer version, code that relies
+	// on the latest version should be gated behind this.
+	DefinitionVersion *WorkflowDefinitionVersion `json:"defVersion,omitempty"`
 }
 
 type EventVersion int
diff --git a/pkg/controller/handler.go b/pkg/controller/handler.go
index e40e4d045..0f653de57 100644
--- a/pkg/controller/handler.go
+++ b/pkg/controller/handler.go
@@ -83,6 +83,16 @@ func (p *Propeller) Initialize(ctx context.Context) error {
 	return p.workflowExecutor.Initialize(ctx)
 }
 
+func SetDefinitionVersionIfEmpty(wf *v1alpha1.FlyteWorkflow, version v1alpha1.WorkflowDefinitionVersion) {
+	if wf.WorkflowMeta == nil {
+		wf.WorkflowMeta = &v1alpha1.WorkflowMeta{}
+	}
+
+	if wf.WorkflowMeta.DefinitionVersion == nil {
+		wf.WorkflowMeta.DefinitionVersion = &version
+	}
+}
+
 // TryMutateWorkflow will try to mutate the workflow by traversing it and reconciling the desired and actual state.
 // The desired state here is the entire workflow is completed, actual state is each nodes current execution state.
 func (p *Propeller) TryMutateWorkflow(ctx context.Context, originalW *v1alpha1.FlyteWorkflow) (*v1alpha1.FlyteWorkflow, error) {
@@ -120,6 +130,7 @@ func (p *Propeller) TryMutateWorkflow(ctx context.Context, originalW *v1alpha1.F
 	if !mutableW.GetExecutionStatus().IsTerminated() {
 		var err error
 		SetFinalizerIfEmpty(mutableW, FinalizerKey)
+		SetDefinitionVersionIfEmpty(mutableW, v1alpha1.LatestWorkflowDefinitionVersion)
 
 		func() {
 			t := p.metrics.RawWorkflowTraversalTime.Start(ctx)
diff --git a/pkg/controller/nodes/subworkflow/launchplan.go b/pkg/controller/nodes/subworkflow/launchplan.go
index 8d14968d0..037c41b88 100644
--- a/pkg/controller/nodes/subworkflow/launchplan.go
+++ b/pkg/controller/nodes/subworkflow/launchplan.go
@@ -56,10 +56,12 @@ func (l *launchPlanHandler) StartLaunchPlan(ctx context.Context, nCtx handler.No
 	if err != nil {
 		return handler.UnknownTransition, err
 	}
-	childID, err := GetChildWorkflowExecutionID(
+
+	childID, err := GetChildWorkflowExecutionIDForExecution(
 		parentNodeExecutionID,
-		nCtx.CurrentAttempt(),
+		nCtx,
 	)
+
 	if err != nil {
 		return handler.DoTransition(handler.TransitionTypeEphemeral, handler.PhaseInfoFailure(core.ExecutionError_SYSTEM, errors.RuntimeExecutionError, "failed to create unique ID", nil)), nil
 	}
@@ -110,15 +112,31 @@ func (l *launchPlanHandler) StartLaunchPlan(ctx context.Context, nCtx handler.No
 	})), nil
 }
 
+func GetChildWorkflowExecutionIDForExecution(parentNodeExecID *core.NodeExecutionIdentifier, nCtx handler.NodeExecutionContext) (*core.WorkflowExecutionIdentifier, error) {
+	// Handle launch plan
+	if nCtx.ExecutionContext().GetDefinitionVersion() == v1alpha1.WorkflowDefinitionVersion0 {
+		return GetChildWorkflowExecutionID(
+			parentNodeExecID,
+			nCtx.CurrentAttempt(),
+		)
+	}
+
+	return GetChildWorkflowExecutionIDV2(
+		parentNodeExecID,
+		nCtx.CurrentAttempt(),
+	)
+}
+
 func (l *launchPlanHandler) CheckLaunchPlanStatus(ctx context.Context, nCtx handler.NodeExecutionContext) (handler.Transition, error) {
 	parentNodeExecutionID, err := getParentNodeExecutionID(nCtx)
 	if err != nil {
 		return handler.UnknownTransition, err
 	}
+
 	// Handle launch plan
-	childID, err := GetChildWorkflowExecutionID(
+	childID, err := GetChildWorkflowExecutionIDForExecution(
 		parentNodeExecutionID,
-		nCtx.CurrentAttempt(),
+		nCtx,
 	)
 
 	if err != nil {
@@ -203,9 +221,9 @@ func (l *launchPlanHandler) HandleAbort(ctx context.Context, nCtx handler.NodeEx
 	if err != nil {
 		return err
 	}
-	childID, err := GetChildWorkflowExecutionID(
+	childID, err := GetChildWorkflowExecutionIDForExecution(
 		parentNodeExecutionID,
-		nCtx.CurrentAttempt(),
+		nCtx,
 	)
 	if err != nil {
 		// THIS SHOULD NEVER HAPPEN
diff --git a/pkg/controller/nodes/subworkflow/util.go b/pkg/controller/nodes/subworkflow/util.go
index 0b5bf715b..cedef8469 100644
--- a/pkg/controller/nodes/subworkflow/util.go
+++ b/pkg/controller/nodes/subworkflow/util.go
@@ -22,3 +22,26 @@ func GetChildWorkflowExecutionID(nodeExecID *core.NodeExecutionIdentifier, attem
 		Name:    name,
 	}, nil
 }
+
+func GetChildWorkflowExecutionIDV2(nodeExecID *core.NodeExecutionIdentifier, attempt uint32) (*core.WorkflowExecutionIdentifier, error) {
+	name, err := encoding.FixedLengthUniqueIDForParts(maxLengthForSubWorkflow, nodeExecID.ExecutionId.Name, nodeExecID.NodeId, strconv.Itoa(int(attempt)))
+	if err != nil {
+		return nil, err
+	}
+
+	// Restriction on name is 20 chars
+	return &core.WorkflowExecutionIdentifier{
+		Project: nodeExecID.ExecutionId.Project,
+		Domain:  nodeExecID.ExecutionId.Domain,
+		Name:    EnsureExecIDWithinLength(nodeExecID.ExecutionId.Name, name, maxLengthForSubWorkflow),
+	}, nil
+}
+
+func EnsureExecIDWithinLength(execID, subName string, maxLength int) string {
+	maxLengthRemaining := maxLength - len(subName)
+	if len(execID) < maxLengthRemaining {
+		return execID + subName
+	}
+
+	return execID[:maxLengthRemaining] + subName
+}