diff --git a/dashcaddy-api/__tests__/error-handler.test.js b/dashcaddy-api/__tests__/error-handler.test.js
index f7f54b8..34a53ab 100644
--- a/dashcaddy-api/__tests__/error-handler.test.js
+++ b/dashcaddy-api/__tests__/error-handler.test.js
@@ -156,18 +156,19 @@ describe('Error Handler', () => {
     });
 
     it('logs non-operational errors as FATAL', () => {
-      const origError = console.error;
-      console.error = jest.fn();
+      const stderrSpy = jest.spyOn(process.stderr, 'write').mockImplementation(() => true);
 
-      const err = new Error('programming bug');
-      errorMiddleware(err, req, res, next);
+      try {
+        const err = new Error('programming bug');
+        errorMiddleware(err, req, res, next);
 
-      expect(console.error).toHaveBeenCalledWith(
-        'FATAL: Non-operational error detected',
-        expect.any(Object)
-      );
-
-      console.error = origError;
+        const calls = stderrSpy.mock.calls.map(c => String(c[0]));
+        const fatalLine = calls.find(l => l.includes('FATAL'));
+        expect(fatalLine).toBeDefined();
+        expect(fatalLine).toContain('programming bug');
+      } finally {
+        stderrSpy.mockRestore();
+      }
     });
   });
 
diff --git a/dashcaddy-api/routes/backups.js b/dashcaddy-api/routes/backups.js
index eeafc5f..a86e124 100644
--- a/dashcaddy-api/routes/backups.js
+++ b/dashcaddy-api/routes/backups.js
@@ -775,7 +775,7 @@ async function getStorageInfo() {
         : 0;
     }
   } catch (error) {
-    console.error('[BackupsRouter] Error getting storage info:', error.message);
+    process.stderr.write(`[BackupsRouter] Error getting storage info: ${error.message}\n`);
   }
 
   return result;
diff --git a/dashcaddy-api/src/auth/providers/email.js b/dashcaddy-api/src/auth/providers/email.js
index e118b86..3d73a72 100644
--- a/dashcaddy-api/src/auth/providers/email.js
+++ b/dashcaddy-api/src/auth/providers/email.js
@@ -410,8 +410,7 @@ class EmailMagicLinkProvider extends AuthProvider {
     if (this.deps.log && typeof this.deps.log.warn === 'function') {
       this.deps.log.warn('auth-magic-dev', marker);
     } else {
-      // eslint-disable-next-line no-console
-      console.warn(marker);
+      process.stderr.write(`${marker}\n`);
     }
   }
 
diff --git a/dashcaddy-api/src/dns/dns-providers/registry.js b/dashcaddy-api/src/dns/dns-providers/registry.js
index 915cf92..b285b8b 100644
--- a/dashcaddy-api/src/dns/dns-providers/registry.js
+++ b/dashcaddy-api/src/dns/dns-providers/registry.js
@@ -16,7 +16,7 @@ class DNSProviderRegistry {
     const instance = new adapterClass({}, {});
     const id = instance.providerId;
     if (this.providers.has(id)) {
-      console.warn(`DNS provider "${id}" already registered, overwriting`);
+      process.stderr.write(`[DNS Registry] Provider "${id}" already registered, overwriting\n`);
     }
     this.providers.set(id, adapterClass);
   }
@@ -88,7 +88,7 @@ class DNSProviderRegistry {
           }
         }
       } catch (err) {
-        console.error(`Failed to load DNS provider from ${file}:`, err.message);
+        process.stderr.write(`[DNS Registry] Failed to load DNS provider from ${file}: ${err.message}\n`);
       }
     }
   }
diff --git a/dashcaddy-api/src/managers/auto-restart-manager.js b/dashcaddy-api/src/managers/auto-restart-manager.js
index 3c7d1d3..04663c3 100644
--- a/dashcaddy-api/src/managers/auto-restart-manager.js
+++ b/dashcaddy-api/src/managers/auto-restart-manager.js
@@ -50,7 +50,7 @@ class AutoRestartManager extends EventEmitter {
     super();
     this.ctx = ctx;
     this.log = ctx.log || console;
-    this.logError = ctx.logError || ((_ctx, err) => console.error(err));
+    this.logError = ctx.logError || ((_ctx, err) => process.stderr.write(`[auto-restart] ${err?.message || err}\n`));
     this.docker = ctx.docker;
     this.healthChecker = ctx.healthChecker;
     this.notification = ctx.notification;
diff --git a/dashcaddy-api/src/managers/config-drift-detector.js b/dashcaddy-api/src/managers/config-drift-detector.js
index dbb677b..899fc7e 100644
--- a/dashcaddy-api/src/managers/config-drift-detector.js
+++ b/dashcaddy-api/src/managers/config-drift-detector.js
@@ -41,7 +41,7 @@ class ConfigDriftDetector extends EventEmitter {
     super();
     this.ctx = ctx;
     this.log = ctx.log || console;
-    this.logError = ctx.logError || ((_c, err) => console.error(err));
+    this.logError = ctx.logError || ((_c, err) => process.stderr.write(`[config-drift] ${err?.message || err}\n`));
     this.docker = ctx.docker;
     this.servicesStateManager = ctx.servicesStateManager;
     this.notification = ctx.notification;
diff --git a/dashcaddy-api/src/security/audit-logger.js b/dashcaddy-api/src/security/audit-logger.js
index 17ae814..86fef28 100644
--- a/dashcaddy-api/src/security/audit-logger.js
+++ b/dashcaddy-api/src/security/audit-logger.js
@@ -184,10 +184,10 @@ class AuditLogger {
         });
       } catch (e) {
         // Non-fatal — security store is a best-effort mirror
-        console.error('[AuditLogger] Security event emit failed:', e.message);
+        process.stderr.write(`[AuditLogger] Security event emit failed: ${e.message}\n`);
       }
     } catch (e) {
-      console.error('[AuditLogger] Failed to write entry:', e.message);
+      process.stderr.write(`[AuditLogger] Failed to write entry: ${e.message}\n`);
     }
   }
 
@@ -199,7 +199,7 @@ class AuditLogger {
       }
       return entries.slice(offset, offset + limit);
     } catch (e) {
-      console.error('[AuditLogger] Failed to read:', e.message);
+      process.stderr.write(`[AuditLogger] Failed to read: ${e.message}\n`);
       return [];
     }
   }
diff --git a/dashcaddy-api/src/security/csrf-protection.js b/dashcaddy-api/src/security/csrf-protection.js
index 7f5be87..97cc7f4 100644
--- a/dashcaddy-api/src/security/csrf-protection.js
+++ b/dashcaddy-api/src/security/csrf-protection.js
@@ -216,14 +216,14 @@ function csrfValidationMiddleware(req, res, next) {
 
   // Validate both values exist
   if (!cookieNonce) {
-    console.warn(`[CSRF] Missing CSRF cookie: ${method} ${req.path} from ${req.ip}`);
+    process.stderr.write(`[CSRF] Missing CSRF cookie: ${method} ${req.path} from ${req.ip}\n`);
     return errorResponse(res, 403, '[DC-100] CSRF token missing', {
       message: 'CSRF cookie not found. Please refresh the page (Ctrl+Shift+R) and try again.'
     });
   }
 
   if (!headerToken) {
-    console.warn(`[CSRF] Missing CSRF header: ${method} ${req.path} from ${req.ip}`);
+    process.stderr.write(`[CSRF] Missing CSRF header: ${method} ${req.path} from ${req.ip}\n`);
     return errorResponse(res, 403, '[DC-100] CSRF token missing', {
       message: 'CSRF token not provided in request headers. Please refresh the page (Ctrl+Shift+R) and try again.'
     });
@@ -247,7 +247,7 @@ function csrfValidationMiddleware(req, res, next) {
     next();
 
   } catch (err) {
-    console.warn(`[CSRF] Invalid CSRF token: ${method} ${req.path} from ${req.ip} - ${err.message}`);
+    process.stderr.write(`[CSRF] Invalid CSRF token: ${method} ${req.path} from ${req.ip} - ${err.message}\n`);
     return errorResponse(res, 403, '[DC-101] CSRF token invalid', {
       message: 'CSRF token validation failed. Please refresh the page (Ctrl+Shift+R) and try again.'
     });
diff --git a/dashcaddy-api/src/utilities/error-handler.js b/dashcaddy-api/src/utilities/error-handler.js
index 093db46..790bd81 100644
--- a/dashcaddy-api/src/utilities/error-handler.js
+++ b/dashcaddy-api/src/utilities/error-handler.js
@@ -34,7 +34,7 @@ function errorMiddleware(err, req, res, next) {
       userId: req.user?.id,
       body: req.body
     }
-  ).catch(e => console.error('Failed to write to error log:', e.message));
+  ).catch(e => process.stderr.write(`[error-handler] Failed to write to error log: ${e.message}\n`));
 
   // Determine if this is an operational error (AppError) or programming error
   const isOperational = err.isOperational || err instanceof AppError;
@@ -65,11 +65,7 @@ function errorMiddleware(err, req, res, next) {
 
   // For non-operational errors, log as fatal
   if (!isOperational) {
-    console.error('FATAL: Non-operational error detected', {
-      error: err.message,
-      stack: err.stack,
-      path: req.path
-    });
+    process.stderr.write(`[FATAL] Non-operational error detected: ${JSON.stringify({ error: err.message, stack: err.stack, path: req.path })}\n`);
   }
 }
 
diff --git a/dashcaddy-api/src/utils/http.js b/dashcaddy-api/src/utils/http.js
index 506e90d..0e52423 100644
--- a/dashcaddy-api/src/utils/http.js
+++ b/dashcaddy-api/src/utils/http.js
@@ -43,7 +43,7 @@ function fetchT(url, opts = {}, timeoutMs = TIMEOUTS.HTTP_DEFAULT) {
   // passes `timeout: N` here, it's almost certainly a bug — we used to silently
   // strip it, which masked the issue. Now we surface it in logs and strip it.
   if ('timeout' in opts) {
-    console.warn(`[fetchT] opts.timeout=${opts.timeout} is ignored — pass timeoutMs as the 3rd arg of fetchT() instead. Called from: ${new Error().stack.split('\n').slice(2, 4).join(' <- ')}`);
+    process.stderr.write(`[fetchT] opts.timeout=${opts.timeout} is ignored — pass timeoutMs as the 3rd arg of fetchT() instead. Called from: ${new Error().stack.split('\n').slice(2, 4).join(' <- ')}\n`);
     const { timeout: _timeout, ...rest } = opts;
     opts = rest;
   }