504 Gateway Timeout Error

Configure longer timeout values for gateway/proxy servers.

# Nginx: increase upstream timeout
location /api/ {
  proxy_read_timeout 120s;
  proxy_connect_timeout 30s;
  proxy_send_timeout 30s;
}

# AWS ALB: increase timeout in console
# Target Group → Attributes → Idle timeout: 120 seconds

Profile and optimize the upstream application to respond faster.

// Add request logging to find slow endpoints
app.use((req, res, next) => {
  const start = Date.now()
  res.on("finish", () => {
    const duration = Date.now() - start
    if (duration > 5000) console.warn(`Slow request: ${req.method} ${req.url} (${duration}ms)`)
  })
  next()
})

Offload long-running tasks to background jobs and return immediately.

app.post("/api/report", async (req, res) => {
  const jobId = await queue.add({ params: req.body })
  res.status(202).json({ jobId, status: "processing" })
  // Client polls GET /api/report/:jobId for result
})