diff --git a/backend/internal/provider/adobe/client.go b/backend/internal/provider/adobe/client.go
index 4db0783..2deca64 100644
--- a/backend/internal/provider/adobe/client.go
+++ b/backend/internal/provider/adobe/client.go
@@ -58,9 +58,8 @@ var profileURLs = []string{
 }
 
 type Client struct {
-	apiKey       string
-	proxy        string
-	arpSessionID string // cached per-client, reused across requests (matches adobe2api)
+	apiKey string
+	proxy  string
 }
 
 func NewClient(apiKey, proxy string) *Client {
@@ -70,17 +69,6 @@ func NewClient(apiKey, proxy string) *Client {
 	}
 }
 
-// getARPSessionID returns a cached ARP session id matching adobe2api's format:
-// base64({"sid":"<uuid>","ftr":"<hex16>_<ts_ms>_<pid>_dUAL43-mnts-ants-d4_31ck__tt"})
-// Generated once per client and reused — adobe2api reuses the same session id per
-// token/profile instead of rotating every request.
-func (c *Client) getARPSessionID() string {
-	if c.arpSessionID != "" {
-		return c.arpSessionID
-	}
-	c.arpSessionID = buildARPSessionID()
-	return c.arpSessionID
-}
 
 func (c *Client) SetProxy(proxy string) {
 	c.proxy = strings.TrimSpace(proxy)
@@ -300,6 +288,7 @@ func (c *Client) FetchAccountProfile(ctx context.Context, token string) (map[str
 				"user-agent",
 			},
 		}
+		defer ReleasePID(token)
 
 		resp, err := sess.client.Do(req)
 		if err != nil {
@@ -470,7 +459,7 @@ func (c *Client) submitImage(ctx context.Context, sess *tlsSession, token, promp
 		"sec-fetch-mode":     {"cors"},
 		"sec-fetch-dest":     {"empty"},
 		"user-agent":         {sess.fp.userAgent},
-		"x-arp-session-id":   {c.getARPSessionID()},
+		"x-arp-session-id":   {buildARPSessionID(token)},
 		http.HeaderOrderKey: {
 			"authorization",
 			"x-api-key",
@@ -569,6 +558,7 @@ func (c *Client) pollImage(ctx context.Context, sess *tlsSession, token, pollURL
 				"user-agent",
 			},
 		}
+		defer ReleasePID(token)
 
 		resp, err := sess.client.Do(req)
 		if err != nil {
@@ -648,7 +638,7 @@ func (c *Client) submitVideo(ctx context.Context, sess *tlsSession, token, endpo
 		"sec-fetch-mode":     {"cors"},
 		"sec-fetch-dest":     {"empty"},
 		"user-agent":         {sess.fp.userAgent},
-		"x-arp-session-id":   {c.getARPSessionID()},
+		"x-arp-session-id":   {buildARPSessionID(token)},
 		http.HeaderOrderKey: {
 			"authorization",
 			"x-api-key",
@@ -753,6 +743,7 @@ func (c *Client) pollVideo(ctx context.Context, sess *tlsSession, token, pollURL
 				"user-agent",
 			},
 		}
+		defer ReleasePID(token)
 
 		resp, err := sess.client.Do(req)
 		if err != nil {
diff --git a/backend/internal/provider/adobe/util.go b/backend/internal/provider/adobe/util.go
index 3a58fcb..5672605 100644
--- a/backend/internal/provider/adobe/util.go
+++ b/backend/internal/provider/adobe/util.go
@@ -7,15 +7,23 @@ import (
 	"encoding/json"
 	"math/big"
 	"net/url"
-	"os"
 	"regexp"
 	"strconv"
 	"strings"
+	"sync"
 	"time"
 
 	"github.com/google/uuid"
 )
 
+// arpPIDPool maps access tokens to unique PIDs so the same account always
+// reuses its PID and different accounts never collide. Guarded by arpPIDMu.
+var (
+	arpPIDMu    sync.Mutex
+	arpTokenPID = map[string]int{} // token → pid
+	arpPIDToken = map[int]string{} // pid → token
+)
+
 // adobeUserIDPat matches Adobe IMS user IDs embedded in cookies (e.g.
 // "4BDA81F069FC6DA40A495FAB@AdobeID").
 var adobeUserIDPat = regexp.MustCompile(`[A-Fa-f0-9]{20,}@AdobeID`)
@@ -96,12 +104,11 @@ func decodeJWTPayload(token string) map[string]any {
 	return out
 }
 
-func buildARPSessionID() string {
+func buildARPSessionID(token string) string {
 	// Matches adobe2api's format exactly:
 	// base64({"sid":"<uuid>","ftr":"<hex16>_<ts_ms>_<pid>_dUAL43-mnts-ants-d4_31ck__tt"})
 	// Two fields only (no "ark") — mirrors what a real browser session sends.
-	pid := os.Getpid()
-	ftr := randomHex(16) + "_" + strconv.FormatInt(time.Now().UnixMilli(), 10) + "_" + strconv.Itoa(pid) + "_dUAL43-mnts-ants-d4_31ck__tt"
+	ftr := randomHex(16) + "_" + strconv.FormatInt(time.Now().UnixMilli(), 10) + "_" + strconv.Itoa(allocPID(token)) + "_dUAL43-mnts-ants-d4_31ck__tt"
 	raw := map[string]any{
 		"sid": uuid.NewString(),
 		"ftr": ftr,
@@ -110,6 +117,39 @@ func buildARPSessionID() string {
 	return base64.StdEncoding.EncodeToString(b)
 }
 
+// allocPID returns a unique PID bound to token. Same token always gets the
+// same PID; different tokens never share a PID. Picks randomly from
+// [1000, 99999] and retries on collision.
+func allocPID(token string) int {
+	arpPIDMu.Lock()
+	defer arpPIDMu.Unlock()
+
+	if pid, ok := arpTokenPID[token]; ok {
+		return pid
+	}
+	for {
+		pid := randomInt(1000, 99999)
+		if _, used := arpPIDToken[pid]; !used {
+			arpPIDToken[pid] = token
+			arpTokenPID[token] = pid
+			return pid
+		}
+	}
+}
+
+// ReleasePID releases the PID bound to token so it can be reused by another
+// account. Call this when a token/session is finished (e.g. after the Adobe
+// API request completes or on token expiry).
+func ReleasePID(token string) {
+	arpPIDMu.Lock()
+	defer arpPIDMu.Unlock()
+
+	if pid, ok := arpTokenPID[token]; ok {
+		delete(arpPIDToken, pid)
+		delete(arpTokenPID, token)
+	}
+}
+
 func randomHex(n int) string {
 	if n <= 0 {
 		return ""