Why should you care?

grep plain text in prod is hopeless; structured logs feed Elasticsearch and alerts.

See it live — copy this example

Paste into your MeanVerse project (Angular + Express + MongoDB), then run with ng serve / node / mongosh as noted.

import pino from 'pino';
import pinoHttp from 'pino-http';

const logger = pino({ level: process.env.LOG_LEVEL ?? 'info' });
app.use(pinoHttp({ logger, genReqId: req => req.headers['x-request-id'] ?? crypto.randomUUID() }));

logger.info({ event: 'transfer_posted', transferId, tenantId, amountCents }, 'Transfer completed');

// Angular global error handler
@Injectable()
export class GlobalErrorHandler implements ErrorHandler {
  handleError(error: unknown) {
    this.log.error({ source: 'angular', error: String(error) });
  }
}

What happened?

• pino outputs JSON one line per log.
• pinoHttp adds req id per request.
• Include domain fields for search.
• Angular reports client errors to same pipeline.

Practice next

1. Replace console.log with pino in API.
2. Pass x-request-id from Nginx through stack.
3. Redact passwords and tokens in serializers.
4. Add child logger with tenantId bound per request.
5. Log slow queries over 200ms threshold.

Remember

Structured JSON logs searchable at scale. Correlation id ties Angular to API lines. Redact secrets and sensitive fields.

Production incident

Transfers fail for one tenant only.

Outcome: Filter tenantId in Kibana finds validation bug in 3 minutes.