diff --git a/backend/src/backtest/index.ts b/backend/src/backtest/index.ts
index 3e30f2a..dda746f 100644
--- a/backend/src/backtest/index.ts
+++ b/backend/src/backtest/index.ts
@@ -2,10 +2,19 @@ import { assertBacktestFeatureEnabled, assertBacktestMode } from './guards.js';
 import { loadHistoricalData } from './data/loadHistoricalData.js';
 import { runBacktestReplay } from './engine/BacktestRunner.js';
 import { assertBacktestStrategyConfigSafe } from './strategySafety.js';
+import { withLogLevel } from '../utils/logger.js';
 import type { BacktestRequest, BacktestResult } from './types.js';
 
 export interface RunBacktestOptions {
     profileSettings?: any;
+    /**
+     * Override log verbosity for the duration of the backtest run.
+     * Default: 'warn' — silences ~5 info logs per candle that the strategy
+     * engine emits during normal operation. Pass 'info' or 'debug' when
+     * diagnosing engine behavior.
+     * See docs/backtest/ENGINE_READINESS.md §3.3.
+     */
+    logLevel?: string;
 }
 
 export const runBacktest = async (
@@ -16,11 +25,12 @@ export const runBacktest = async (
     assertBacktestMode(request.mode);
     assertBacktestStrategyConfigSafe(request.strategyConfig);
     const historical = await loadHistoricalData(request);
-    return runBacktestReplay({
+    const level = options.logLevel ?? 'warn';
+    return withLogLevel(level, () => runBacktestReplay({
         request,
         dataset: historical.dataset,
         replayWindow: historical.window,
         dataSourceType: historical.source,
         profileSettings: options.profileSettings
-    });
+    }));
 };
diff --git a/backend/src/utils/logger.ts b/backend/src/utils/logger.ts
index 5bf8f28..4874933 100644
--- a/backend/src/utils/logger.ts
+++ b/backend/src/utils/logger.ts
@@ -1,19 +1,42 @@
-import winston from 'winston';
-
-const logger = winston.createLogger({
-  level: 'info',
-  format: winston.format.combine(
-    winston.format.timestamp(),
-    winston.format.json()
-  ),
-  transports: [
-    new winston.transports.Console({
-      format: winston.format.combine(
-        winston.format.colorize(),
-        winston.format.simple()
-      ),
-    }),
-  ],
-});
-
-export default logger;
+import winston from 'winston';
+
+// LOG_LEVEL env override — allows operators / tests / backtest to dial down
+// noise without code changes. Defaults to 'info' to preserve existing behavior.
+const initialLevel = process.env.LOG_LEVEL || 'info';
+
+const logger = winston.createLogger({
+  level: initialLevel,
+  format: winston.format.combine(
+    winston.format.timestamp(),
+    winston.format.json()
+  ),
+  transports: [
+    new winston.transports.Console({
+      format: winston.format.combine(
+        winston.format.colorize(),
+        winston.format.simple()
+      ),
+    }),
+  ],
+});
+
+/**
+ * Run a function with the logger temporarily set to a lower verbosity, then
+ * restore the prior level. Used by the backtest entry point so a 5,000-candle
+ * run doesn't emit ~25,000 log lines (see docs/backtest/ENGINE_READINESS.md
+ * §3.3). Safe across throws — the original level is always restored.
+ */
+export const withLogLevel = async <T>(
+  level: string,
+  fn: () => Promise<T> | T
+): Promise<T> => {
+  const previous = logger.level;
+  logger.level = level;
+  try {
+    return await fn();
+  } finally {
+    logger.level = previous;
+  }
+};
+
+export default logger;