⚡ Bolt: [performance improvement] Defer allocations in orbital prediction

.jules/bolt.md

@@ -0,0 +1,4 @@
+
+## 2026-05-19 - Defer dictionary allocation in orbital pass loop
+**Learning:** Generating dictionaries and formatting datetime strings in a tight loop where the result is immediately discarded for >90% of iterations creates a massive, unnecessary performance bottleneck.
+**Action:** Always defer expensive object allocations and string formatting operations until *after* filtering conditions (like visibility checks) have passed.

backend/api/routers/orbital.py

@@ -187,14 +187,15 @@ async def get_passes(
             r_ecef = teme_to_ecef(r, jd, fr)
             az, el, rng = ecef_to_topocentric(obs_ecef, r_ecef, lat, lon)
 
-            point = {
-                "t": t.strftime("%Y-%m-%dT%H:%M:%SZ"),
-                "az": round(az, 2),
-                "el": round(el, 2),
-                "slant_range_km": round(rng, 3),
-            }
-
             if el >= min_elevation:
+                # Defer string formatting and allocation until we know satellite is visible
+                point = {
+                    "t": t.strftime("%Y-%m-%dT%H:%M:%SZ"),
+                    "az": round(az, 2),
+                    "el": round(el, 2),
+                    "slant_range_km": round(rng, 3),
+                }
+
                 if not in_pass:
                     in_pass = True
                     current_pass_points = []