diff --git a/targeting/engine.go b/targeting/engine.go
index 79dab32..a3e2143 100644
--- a/targeting/engine.go
+++ b/targeting/engine.go
@@ -243,7 +243,7 @@ func (e *Engine) EvaluateContextResolved(ctx context.Context, resolved *Resolved
 	// 5. Resolve artifact topics from Store (per-request, can't cache).
 	var artifactTopics []string
 	for _, artifact := range artifactRefs {
-		topics, err := e.store.SetMembers(ctx, "topics:artifact:"+artifact)
+		topics, err := e.store.SetMembers(ctx, keyPrefixTopicsArtifact+artifact)
 		if err != nil {
 			e.metrics.StoreError(StageTopicMatch, err)
 		} else {
@@ -347,8 +347,8 @@ func (e *Engine) EvaluateIdentityResolved(ctx context.Context, resolved *Resolve
 	keys := make([]string, 0, len(identities)*2)
 	for _, uid := range identities {
 		hash := HashToken(uid.UserToken)
-		keys = append(keys, "user:profile:"+hash)
-		keys = append(keys, "user:exposures:"+hash)
+		keys = append(keys, keyPrefixUserProfile+hash)
+		keys = append(keys, keyPrefixUserExposures+hash)
 	}
 
 	// 2. Single MGet — 1 round-trip.
@@ -452,7 +452,7 @@ func (e *Engine) SetUserProfile(ctx context.Context, userToken string, segments
 	if err != nil {
 		return err
 	}
-	return e.store.Set(ctx, "user:profile:"+hash, string(data), 0)
+	return e.store.Set(ctx, keyPrefixUserProfile+hash, string(data), 0)
 }
 
 // SetUserProfiles writes segment memberships for multiple users in a single batch.
@@ -466,11 +466,27 @@ func (e *Engine) SetUserProfiles(ctx context.Context, profiles map[string]map[st
 		if err != nil {
 			return err
 		}
-		kvs["user:profile:"+hash] = string(data)
+		kvs[keyPrefixUserProfile+hash] = string(data)
 	}
 	return e.store.MSet(ctx, kvs, 0)
 }
 
+// DeleteUserProfile removes a user's segment profile.
+func (e *Engine) DeleteUserProfile(ctx context.Context, userToken string) error {
+	hash := HashToken(userToken)
+	return e.store.Del(ctx, keyPrefixUserProfile+hash)
+}
+
+// DeleteUserProfiles removes segment profiles for multiple users in a single batch.
+// The userTokens slice contains user tokens.
+func (e *Engine) DeleteUserProfiles(ctx context.Context, userTokens []string) error {
+	keys := make([]string, len(userTokens))
+	for i, userToken := range userTokens {
+		keys[i] = keyPrefixUserProfile + HashToken(userToken)
+	}
+	return e.store.MDel(ctx, keys...)
+}
+
 // RecordExposure records an impression to the exposure log for all UIDs.
 // Each UID's exposure log is read, the new entry is appended,
 // old entries are pruned, and the log is written back.
@@ -529,7 +545,7 @@ func (e *Engine) RecordExposure(ctx context.Context, req *ExposeRequest) (*Expos
 	// Write to each UID's exposure log. Capture the first UID's log for the response.
 	var firstLog BinaryExposureLog
 	for i, hash := range hashes {
-		key := "user:exposures:" + hash
+		key := keyPrefixUserExposures + hash
 
 		val, _, err := e.store.Get(ctx, key)
 		if err != nil {
@@ -636,7 +652,7 @@ func (e *Engine) checkURLFilter(ctx context.Context, artifacts []string, pkgID s
 		urlHash := HashURL(artifact)
 
 		if cfg.URLBlocklist {
-			blocked, err := e.store.SetIsMember(ctx, "url:blocklist:"+pkgID, urlHash)
+			blocked, err := e.store.SetIsMember(ctx, keyPrefixURLBlocklist+pkgID, urlHash)
 			if err != nil {
 				return false, err
 			}
@@ -646,7 +662,7 @@ func (e *Engine) checkURLFilter(ctx context.Context, artifacts []string, pkgID s
 		}
 
 		if cfg.URLAllowlist {
-			allowKey := "url:allowlist:" + pkgID
+			allowKey := keyPrefixURLAllowlist + pkgID
 			exists, err := e.store.Exists(ctx, allowKey)
 			if err != nil {
 				return false, err
@@ -672,7 +688,7 @@ func (e *Engine) checkTopicMatch(ctx context.Context, artifacts []string, pkgID
 		return true, nil
 	}
 	for _, artifact := range artifacts {
-		intersection, err := e.store.SetIntersect(ctx, "topics:package:"+pkgID, "topics:artifact:"+artifact)
+		intersection, err := e.store.SetIntersect(ctx, keyPrefixTopicsPackage+pkgID, keyPrefixTopicsArtifact+artifact)
 		if err != nil {
 			return false, err
 		}
diff --git a/targeting/identity_config.go b/targeting/identity_config.go
index 7a731bb..0ecd627 100644
--- a/targeting/identity_config.go
+++ b/targeting/identity_config.go
@@ -10,9 +10,9 @@ import (
 // PackageIdentityConfig is the identity-side configuration for a package,
 // stored in the Store as JSON at key "config:pkg:{packageID}".
 type PackageIdentityConfig struct {
-	CampaignID     string             `json:"campaign_id,omitempty"`
+	CampaignID     string              `json:"campaign_id,omitempty"`
 	FrequencyRules []FrequencyRuleJSON `json:"frequency_rules,omitempty"`
-	TargetSegments []string           `json:"target_segments,omitempty"`
+	TargetSegments []string            `json:"target_segments,omitempty"`
 }
 
 // CampaignFreqConfig is the frequency cap configuration for a campaign,
@@ -42,7 +42,7 @@ func toFrequencyRules(rules []FrequencyRuleJSON) []FrequencyRule {
 // loadPackageIdentityConfig reads identity config for a package from the Store.
 // Returns nil if no config is found (package has no identity dimensions).
 func loadPackageIdentityConfig(ctx context.Context, store Store, pkgID string) (*PackageIdentityConfig, error) {
-	key := fmt.Sprintf("config:pkg:%s", pkgID)
+	key := keyPrefixConfigPkg + pkgID
 	val, ok, err := store.Get(ctx, key)
 	if err != nil {
 		return nil, err
@@ -64,7 +64,7 @@ func batchLoadPackageContextConfigs(ctx context.Context, store Store, pkgIDs []s
 	}
 	keys := make([]string, len(pkgIDs))
 	for i, id := range pkgIDs {
-		keys[i] = fmt.Sprintf("config:pkg:%s:context", id)
+		keys[i] = keyPrefixConfigPkg + id + ":context"
 	}
 	values, err := store.MGet(ctx, keys...)
 	if err != nil {
@@ -91,7 +91,7 @@ func batchLoadPackageIdentityConfigs(ctx context.Context, store Store, pkgIDs []
 	}
 	keys := make([]string, len(pkgIDs))
 	for i, id := range pkgIDs {
-		keys[i] = fmt.Sprintf("config:pkg:%s", id)
+		keys[i] = keyPrefixConfigPkg + id
 	}
 	values, err := store.MGet(ctx, keys...)
 	if err != nil {
@@ -118,7 +118,7 @@ func batchLoadCampaignFreqConfigs(ctx context.Context, store Store, campaignIDs
 	}
 	keys := make([]string, len(campaignIDs))
 	for i, id := range campaignIDs {
-		keys[i] = fmt.Sprintf("config:campaign:%s", id)
+		keys[i] = keyPrefixConfigCampaign + id
 	}
 	values, err := store.MGet(ctx, keys...)
 	if err != nil {
@@ -144,7 +144,7 @@ func SeedPackageIdentityConfig(ctx context.Context, store Store, pkgID string, c
 	if err != nil {
 		return err
 	}
-	return store.Set(ctx, fmt.Sprintf("config:pkg:%s", pkgID), string(data), 0)
+	return store.Set(ctx, keyPrefixConfigPkg+pkgID, string(data), 0)
 }
 
 // SeedCampaignFreqConfig writes frequency config for a campaign to any Store.
@@ -153,13 +153,13 @@ func SeedCampaignFreqConfig(ctx context.Context, store Store, campaignID string,
 	if err != nil {
 		return err
 	}
-	return store.Set(ctx, fmt.Sprintf("config:campaign:%s", campaignID), string(data), 0)
+	return store.Set(ctx, keyPrefixConfigCampaign+campaignID, string(data), 0)
 }
 
 // loadCampaignFreqConfig reads frequency cap config for a campaign from the Store.
 // Returns nil if no config is found.
 func loadCampaignFreqConfig(ctx context.Context, store Store, campaignID string) (*CampaignFreqConfig, error) {
-	key := fmt.Sprintf("config:campaign:%s", campaignID)
+	key := keyPrefixConfigCampaign + campaignID
 	val, ok, err := store.Get(ctx, key)
 	if err != nil {
 		return nil, err
diff --git a/targeting/mock_store.go b/targeting/mock_store.go
index fced5ec..5cbbe0b 100644
--- a/targeting/mock_store.go
+++ b/targeting/mock_store.go
@@ -3,7 +3,6 @@ package targeting
 import (
 	"context"
 	"encoding/json"
-	"fmt"
 	"sort"
 	"sync"
 	"time"
@@ -63,7 +62,7 @@ func (m *MockStore) SetPackageIdentityConfig(pkgID string, cfg PackageIdentityCo
 	data, _ := json.Marshal(cfg)
 	m.mu.Lock()
 	defer m.mu.Unlock()
-	m.strings[fmt.Sprintf("config:pkg:%s", pkgID)] = stringEntry{value: string(data)}
+	m.strings[keyPrefixConfigPkg+pkgID] = stringEntry{value: string(data)}
 }
 
 // SetCampaignFreqConfig stores frequency config for a campaign. Test helper.
@@ -71,7 +70,7 @@ func (m *MockStore) SetCampaignFreqConfig(campaignID string, cfg CampaignFreqCon
 	data, _ := json.Marshal(cfg)
 	m.mu.Lock()
 	defer m.mu.Unlock()
-	m.strings[fmt.Sprintf("config:campaign:%s", campaignID)] = stringEntry{value: string(data)}
+	m.strings[keyPrefixConfigCampaign+campaignID] = stringEntry{value: string(data)}
 }
 
 // SetMediaBuy stores a media buy and adds it to the seller's set. Test helper.
@@ -80,7 +79,7 @@ func (m *MockStore) SetMediaBuy(mb MediaBuy) {
 	m.mu.Lock()
 	defer m.mu.Unlock()
 	// Add to seller set.
-	sellerKey := "mediabuy:seller:" + mb.SellerID
+	sellerKey := keyPrefixMediaBuySeller + mb.SellerID
 	s, ok := m.sets[sellerKey]
 	if !ok {
 		s = make(map[string]struct{})
@@ -88,7 +87,7 @@ func (m *MockStore) SetMediaBuy(mb MediaBuy) {
 	}
 	s[mb.MediaBuyID] = struct{}{}
 	// Store media buy JSON.
-	m.strings["mediabuy:"+mb.MediaBuyID] = stringEntry{value: string(data)}
+	m.strings[keyPrefixMediaBuy+mb.MediaBuyID] = stringEntry{value: string(data)}
 }
 
 // SetUserProfile stores a user's segment memberships. Test helper.
@@ -98,7 +97,7 @@ func (m *MockStore) SetUserProfile(token string, segments map[string]float64) {
 	data, _ := json.Marshal(profile)
 	m.mu.Lock()
 	defer m.mu.Unlock()
-	m.strings["user:profile:"+hash] = stringEntry{value: string(data)}
+	m.strings[keyPrefixUserProfile+hash] = stringEntry{value: string(data)}
 }
 
 // SetUserExposures stores a user's exposure log in binary format. Test helper.
@@ -107,13 +106,13 @@ func (m *MockStore) SetUserExposures(token string, entries []ExposureEntry) {
 	bin := EncodeBinaryExposureLog(entries)
 	m.mu.Lock()
 	defer m.mu.Unlock()
-	m.strings["user:exposures:"+hash] = stringEntry{value: string(bin)}
+	m.strings[keyPrefixUserExposures+hash] = stringEntry{value: string(bin)}
 }
 
 // AddExposure appends an exposure entry to a user's log. Test helper.
 func (m *MockStore) AddExposure(token string, entry ExposureEntry) {
 	hash := HashToken(token)
-	key := "user:exposures:" + hash
+	key := keyPrefixUserExposures + hash
 	m.mu.Lock()
 	defer m.mu.Unlock()
 	existing := BinaryExposureLog(m.strings[key].value)
@@ -127,7 +126,7 @@ func (m *MockStore) SetPackageContextConfig(pkgID string, cfg PackageContextConf
 	data, _ := json.Marshal(cfg)
 	m.mu.Lock()
 	defer m.mu.Unlock()
-	m.strings[fmt.Sprintf("config:pkg:%s:context", pkgID)] = stringEntry{value: string(data)}
+	m.strings[keyPrefixConfigPkg+pkgID+":context"] = stringEntry{value: string(data)}
 }
 
 func (m *MockStore) SetIsMember(_ context.Context, key, member string) (bool, error) {
@@ -334,6 +333,22 @@ func (m *MockStore) MSet(_ context.Context, kvs map[string]string, ttl time.Dura
 	return nil
 }
 
+func (m *MockStore) Del(_ context.Context, key string) error {
+	m.mu.Lock()
+	defer m.mu.Unlock()
+	delete(m.strings, key)
+	return nil
+}
+
+func (m *MockStore) MDel(_ context.Context, keys ...string) error {
+	m.mu.Lock()
+	defer m.mu.Unlock()
+	for _, key := range keys {
+		delete(m.strings, key)
+	}
+	return nil
+}
+
 // isExpired checks key-level expiry. Must be called with lock held.
 func (m *MockStore) isExpired(key string) bool {
 	exp, ok := m.expiry[key]
diff --git a/targeting/resolver.go b/targeting/resolver.go
index 1be9fa3..6689dd7 100644
--- a/targeting/resolver.go
+++ b/targeting/resolver.go
@@ -38,7 +38,7 @@ type MediaBuyPackage struct {
 // Total: 2 Store round-trips (1 SetMembers + 1 MGet) regardless of media buy count.
 func ResolvePackages(ctx context.Context, store Store, sellerID, propertyID, country string, now time.Time) ([]tmproto.AvailablePackage, error) {
 	// 1. Get all media buy IDs for this seller.
-	mbIDs, err := store.SetMembers(ctx, "mediabuy:seller:"+sellerID)
+	mbIDs, err := store.SetMembers(ctx, keyPrefixMediaBuySeller+sellerID)
 	if err != nil {
 		return nil, fmt.Errorf("resolve media buys for seller %s: %w", sellerID, err)
 	}
@@ -49,7 +49,7 @@ func ResolvePackages(ctx context.Context, store Store, sellerID, propertyID, cou
 	// 2. Batch-load all media buy JSON.
 	keys := make([]string, len(mbIDs))
 	for i, id := range mbIDs {
-		keys[i] = "mediabuy:" + id
+		keys[i] = keyPrefixMediaBuy + id
 	}
 	values, err := store.MGet(ctx, keys...)
 	if err != nil {
@@ -157,14 +157,14 @@ func Resolve(ctx context.Context, store Store, sellerID, propertyID, country str
 		}
 
 		// Topic index: load topic set from Store.
-		topics, _ := store.SetMembers(ctx, "topics:package:"+pkgID)
+		topics, _ := store.SetMembers(ctx, keyPrefixTopicsPackage+pkgID)
 		for _, topic := range topics {
 			topicIdx[topic] = append(topicIdx[topic], pkgID)
 		}
 
 		// URL blocklist index: load blocklist from Store.
 		if cc := ctxConfigs[pkgID]; cc != nil && cc.URLBlocklist {
-			blocked, _ := store.SetMembers(ctx, "url:blocklist:"+pkgID)
+			blocked, _ := store.SetMembers(ctx, keyPrefixURLBlocklist+pkgID)
 			for _, hash := range blocked {
 				urlBlockIdx[hash] = append(urlBlockIdx[hash], pkgID)
 			}
@@ -172,7 +172,7 @@ func Resolve(ctx context.Context, store Store, sellerID, propertyID, country str
 
 		// URL allowlist: load allowlist from Store.
 		if cc := ctxConfigs[pkgID]; cc != nil && cc.URLAllowlist {
-			allowed, _ := store.SetMembers(ctx, "url:allowlist:"+pkgID)
+			allowed, _ := store.SetMembers(ctx, keyPrefixURLAllowlist+pkgID)
 			if len(allowed) > 0 {
 				set := make(map[string]struct{}, len(allowed))
 				for _, hash := range allowed {
diff --git a/targeting/store.go b/targeting/store.go
index a74ac42..55cbda6 100644
--- a/targeting/store.go
+++ b/targeting/store.go
@@ -5,6 +5,20 @@ import (
 	"time"
 )
 
+// Store key prefixes.
+const (
+	keyPrefixUserProfile    = "user:profile:"
+	keyPrefixUserExposures  = "user:exposures:"
+	keyPrefixTopicsArtifact = "topics:artifact:"
+	keyPrefixTopicsPackage  = "topics:package:"
+	keyPrefixURLBlocklist   = "url:blocklist:"
+	keyPrefixURLAllowlist   = "url:allowlist:"
+	keyPrefixMediaBuySeller = "mediabuy:seller:"
+	keyPrefixMediaBuy       = "mediabuy:"
+	keyPrefixConfigPkg      = "config:pkg:"
+	keyPrefixConfigCampaign = "config:campaign:"
+)
+
 // Store is a storage backend for the targeting engine.
 // Implementations wrap Valkey/Redis or an in-memory mock.
 type Store interface {
@@ -43,4 +57,10 @@ type Store interface {
 
 	// MSet stores multiple key-value pairs with an optional TTL. Zero TTL means no expiry.
 	MSet(ctx context.Context, kvs map[string]string, ttl time.Duration) error
+
+	// Del removes a key. It is a no-op if the key does not exist.
+	Del(ctx context.Context, key string) error
+
+	// MDel removes multiple keys. It is a no-op for keys that do not exist.
+	MDel(ctx context.Context, keys ...string) error
 }
diff --git a/targeting/valkeystore/store.go b/targeting/valkeystore/store.go
index 2ed3dd6..693b3e9 100644
--- a/targeting/valkeystore/store.go
+++ b/targeting/valkeystore/store.go
@@ -101,6 +101,17 @@ func (s *Store) MGet(ctx context.Context, keys ...string) ([]string, error) {
 	return results, nil
 }
 
+func (s *Store) Del(ctx context.Context, key string) error {
+	return s.rdb.Del(ctx, key).Err()
+}
+
+func (s *Store) MDel(ctx context.Context, keys ...string) error {
+	if len(keys) == 0 {
+		return nil
+	}
+	return s.rdb.Del(ctx, keys...).Err()
+}
+
 func (s *Store) MSet(ctx context.Context, kvs map[string]string, ttl time.Duration) error {
 	if len(kvs) == 0 {
 		return nil