perf: bound concurrency in authService profile hydration

Co-authored-by: PR0M3TH3AN <[email protected]>

CONTEXT.md

@@ -1,3 +1,25 @@
-Node Version: v22.22.0
-NPM Version: 11.7.0
-Date: Thu Feb 12 14:32:45 UTC 2026
+# CONTEXT - bitvid-perf-agent
+
+## Goal
+Daily, measurable improvement of app responsiveness by identifying and remediating background CPU/network work that degrades UX — while also ensuring user-facing docs (/content) reflect the actual runtime behavior of upload/contribution flows.
+
+## Scope
+- Repo: `PR0M3TH3AN/bitvid` (unstable branch).
+- Focus Areas:
+  - P0: Login/auth, relay initialization, decryption (hashtags, subscriptions, blocks, watch history).
+  - P1: Initial UI responsiveness (profile cache, relay load).
+  - P2: User-initiated background features (WebTorrent).
+  - Docs: `/content` (user-facing docs), ensuring upload/contribution docs match code.
+
+## Constraints
+- Never invent files, APIs, libraries, or behaviors.
+- Prefer minimal incremental changes.
+- Keep build/tests green.
+- Preserve repo style and architecture.
+- Security-critical changes require human signoff.
+
+## Definition of Done
+- Performance issues identified and fixed with small, safe PRs.
+- Docs in `/content` matched to code.
+- `daily-perf-report` generated.
+- Artifacts (`TODO.md`, `DECISIONS.md`, `TEST_LOG.md`) updated.

DECISIONS.md

@@ -23,3 +23,14 @@ Ran a daily dependency audit. Found `esbuild` (0.27.2 -> 0.27.3) as a safe candi
 - **Outcome:** BLOCKED (Major Version).
 - **Reason:** Major version bump (v3 -> v4) carries significant risk of breaking changes.
 - **Action:** Existing issue `issues/upgrade-tailwindcss.md` is sufficient.
+
+## 2026-02-18: Performance - Bounded Concurrency in AuthService
+
+### Context
+`loadOwnProfile` in `js/services/authService.js` was using `Promise.allSettled` on all background relays simultaneously. For users with many relays (e.g., 50+), this caused a massive spike in network requests and CPU usage during login/startup.
+
+### Decision: Use `pMap` with Concurrency Limit
+- **Proposal:** Replace `Promise.allSettled` with `pMap` for background relays.
+- **Outcome:** IMPLEMENTED.
+- **Reason:** To prevent network saturation and UI freeze.
+- **Details:** Used `RELAY_BACKGROUND_CONCURRENCY` (3) to limit concurrent background requests. Fast relays (top 3) are still fetched in parallel (unbounded, but small set).

TODO.md

@@ -9,3 +9,6 @@
 
 ## Priority: Low (Maintenance)
 - [ ] Batch upgrade dev dependencies (`stylelint`, `postcss-import`).
+
+## Priority: High (Performance)
+- [x] Bound concurrency in `authService.js` for profile hydration (P0).

daily-perf-report-2026-02-18.md

@@ -0,0 +1,15 @@
+# Daily Performance Report - 2026-02-18
+
+**Summary:** Bounded concurrency in `authService` profile hydration; verified upload docs.
+
+## Findings & Fixes
+- **P0 Fix:** `js/services/authService.js` was launching unbounded concurrent requests for profile hydration.
+  - **Fix:** Implemented `pMap` with `RELAY_BACKGROUND_CONCURRENCY` (3) for background relays.
+  - **Impact:** Prevents network saturation for users with many relays.
+- **Docs Audit:** Verified `content/docs/guides/upload-content.md` correctly specifies port 3000 for CORS. No changes needed.
+
+## Metrics
+- **Tests:** `tests/authService.test.mjs` and `tests/auth-service.test.mjs` passed.
+
+## Artifacts
+- Updated `CONTEXT.md`, `TODO.md`, `DECISIONS.md`, `TEST_LOG.md`.

js/services/authService.js

@@ -43,6 +43,8 @@ import {
   normalizeProviderId,
   normalizeAuthType,
 } from "./authUtils.js";
+import { pMap } from "../utils/asyncUtils.js";
+import { RELAY_BACKGROUND_CONCURRENCY } from "../nostr/relayConstants.js";
 
 export default class AuthService {
   constructor({
@@ -1146,21 +1148,30 @@ export default class AuthService {
         true,
       ),
     );
-    const backgroundPromises = backgroundRelays.map((relayUrl) =>
-      this.fetchProfileFromRelay(
-        relayUrl,
-        filter,
-        normalized,
-        BACKGROUND_PROFILE_TIMEOUT_MS,
-        false,
-      ),
-    );
 
-    const background = Promise.allSettled([
-      ...fastPromises,
-      ...backgroundPromises,
+    const background = Promise.all([
+      Promise.allSettled(fastPromises),
+      pMap(
+        backgroundRelays,
+        async (relayUrl) => {
+          try {
+            const value = await this.fetchProfileFromRelay(
+              relayUrl,
+              filter,
+              normalized,
+              BACKGROUND_PROFILE_TIMEOUT_MS,
+              false,
+            );
+            return { status: "fulfilled", value };
+          } catch (reason) {
+            return { status: "rejected", reason };
+          }
+        },
+        { concurrency: RELAY_BACKGROUND_CONCURRENCY },
+      ),
     ])
-      .then((outcomes) => {
+      .then(([fastOutcomes, backgroundOutcomes]) => {
+        const outcomes = [...fastOutcomes, ...backgroundOutcomes];
         const aggregated = [];
         outcomes.forEach((outcome) => {
           if (outcome.status === "fulfilled") {