Scalable APIs for Distributed Generation with Node.js/TypeScript on AWS

Monitoring Distributed Generation (DG) solar power plants requires fast and reliable data ingestion. Photovoltaic inverters send generation logs every 5 or 15 minutes, generating a constant telemetry traffic that needs to be processed, stored, and utilized for billing energy balance.

In this article, I present the design of a resilient microservices architecture built with Node.js, TypeScript, and hosted on AWS, combining serverless processing with event-driven message buses.

Architecture Design

To ensure scalability with low operational costs, we implemented the following API topology:

1. API Gateway: Public entry point for receiving JSON payloads sent by inverters.
2. AWS SQS (Simple Queue Service): Immediate decoupling of requests to avoid bottlenecks during telemetry spikes.
3. AWS Lambda (Serverless Node.js): Functions focused on parsing data payloads, validating electrical parameters, and storing consolidated data.
4. AWS Aurora PostgreSQL: Structured final storage for quick reports and operational auditing.

Code Sample (TypeScript)

The TypeScript controller below showcases a clean structure for validating data using validation decorators and static typing:

import { Request, Response } from 'express';
export class InverterController {
  async processTelemetry(req: Request, res: Response) {
    const { inverterId, activePowerKwh, timestamp } = req.body;
    
    // Asynchronous processing and queueing
    console.log([INFO] Telemetria recebida do inversor ${inverterId});
    return res.status(202).json({ status: 'queued' });
  }
}

From the plant to the queue

The controller returns 202 and the work continues on SQS. Without the queue, an inverter spike at noon holds the API.

aws sqs send-message \
  --queue-url "$QUEUE_URL" \
  --message-body '{"inverterId":"INV-14","activePowerKwh":4.2,"timestamp":"2026-10-01T15:00:00Z"}'

On Lambda the same message is typed. If activePowerKwh is not a number, the function drops it onto the DLQ instead of writing junk into Aurora.

type Telemetry = {
  inverterId: string;
  activePowerKwh: number;
  timestamp: string;
};
export function parseTelemetry(body: string): Telemetry {
  const data = JSON.parse(body) as Telemetry;
  if (typeof data.activePowerKwh !== "number") {
    throw new Error("invalid activePowerKwh");
  }
  return data;
}

Benefits of TypeScript in Solar Engineering

The use of static typing prevents critical inconsistencies in complex mathematical calculations for energy allocation in solar energy cooperatives, ensuring a much cleaner code free of classic mathematical bugs from dynamic JavaScript.