diff --git a/backend/main.py b/backend/main.py
index 38207f0..0f1dd27 100644
--- a/backend/main.py
+++ b/backend/main.py
@@ -4,7 +4,6 @@ import asyncio
 import hashlib
 import logging
 import os
-import time
 from contextlib import asynccontextmanager
 from datetime import datetime, timezone
 from typing import Any
@@ -113,7 +112,7 @@ app.add_middleware(
 @app.get("/health")
 @app.get("/api/health")
 async def health() -> dict[str, Any]:
-    return {"status": "ok", "timestamp": int(time.time())}
+    return {"status": "ok"}
 
 
 @app.post("/api/register", response_model=RegisterResponse)
@@ -153,7 +152,7 @@ async def signal(body: SignalRequest) -> SignalResponse:
         f"⏰ {ts.strftime('%H:%M:%S')} UTC\n"
         f"{geo_info}"
     )
-    await telegram.send_message(text)
+    asyncio.create_task(telegram.send_message(text))
 
     return SignalResponse(status="ok", signal_id=signal_id)
 
diff --git a/backend/telegram.py b/backend/telegram.py
index 0436dea..b7018e9 100644
--- a/backend/telegram.py
+++ b/backend/telegram.py
@@ -17,24 +17,23 @@ _TELEGRAM_API = "https://api.telegram.org/bot{token}/{method}"
 async def send_message(text: str) -> None:
     url = _TELEGRAM_API.format(token=config.BOT_TOKEN, method="sendMessage")
     async with httpx.AsyncClient(timeout=10) as client:
-        while True:
+        for attempt in range(3):
             resp = await client.post(url, json={"chat_id": config.CHAT_ID, "text": text})
             if resp.status_code == 429:
                 retry_after = resp.json().get("parameters", {}).get("retry_after", 30)
-                logger.warning("Telegram 429, sleeping %s sec", retry_after)
-                await asyncio.sleep(retry_after)
+                sleep = retry_after * (attempt + 1)
+                logger.warning("Telegram 429, sleeping %s sec (attempt %d)", sleep, attempt + 1)
+                await asyncio.sleep(sleep)
                 continue
             if resp.status_code >= 500:
                 logger.error("Telegram 5xx: %s", resp.text)
                 await asyncio.sleep(30)
-                resp2 = await client.post(
-                    url, json={"chat_id": config.CHAT_ID, "text": text}
-                )
-                if resp2.status_code != 200:
-                    logger.error("Telegram retry failed: %s", resp2.text)
+                continue
             elif resp.status_code != 200:
                 logger.error("Telegram error %s: %s", resp.status_code, resp.text)
             break
+        else:
+            logger.error("Telegram send_message: all 3 attempts failed, message dropped")
 
 
 async def set_webhook(url: str, secret: str) -> None:
diff --git a/tests/test_arch_013.py b/tests/test_arch_013.py
index b70c682..307ffbc 100644
--- a/tests/test_arch_013.py
+++ b/tests/test_arch_013.py
@@ -54,14 +54,14 @@ async def test_health_returns_status_ok():
 
 
 @pytest.mark.asyncio
-async def test_health_returns_timestamp():
-    """GET /health должен вернуть поле timestamp в JSON."""
+async def test_health_no_timestamp():
+    """GET /health не должен возвращать поле timestamp (устраняет time-based fingerprinting)."""
     async with make_app_client() as client:
         response = await client.get("/health")
 
     data = response.json()
-    assert "timestamp" in data
-    assert isinstance(data["timestamp"], int)
+    assert "timestamp" not in data
+    assert data == {"status": "ok"}
 
 
 @pytest.mark.asyncio