jgcmarins

Node.js API Performance Playbook

Goal

Maximize throughput and reduce latency without changing infrastructure.

This playbook documents practical patterns that scaled an API from 100 req/s → 50,000 req/s on the same machine and database.

---

jgcmarins

Node.js API Performance Optimization — Technical Specification

Overview

This document outlines performance optimization best practices for Node.js APIs based on real-world improvements where throughput increased from 100 req/s to 50,000 req/s on the same infrastructure (same machine and database).

No changes were made to:

• Programming language
• System architecture

jgcmarins

FROM node:22.16-alpine AS builder
WORKDIR /app
COPY package.json yarn.lock ./
RUN yarn install --frozen-lockfile
COPY . .
RUN yarn build
RUN rm -rf node_modules && yarn install --production --frozen-lockfile

FROM alpine AS runtime
WORKDIR /app

jgcmarins

MYSQL_ROOT_PASSWORD=
MYSQL_DATABASE=
MYSQL_USER=
MYSQL_PASSWORD=

jgcmarins

/* eslint-disable react-hooks/rules-of-hooks */
// 24:33  error  React Hook "useNextRouter" is called conditionally. React Hooks must be called in the exact same order in every component render           react-hooks/rules-of-hooks
// 25:43  error  React Hook "useReactRouterNavigate" is called conditionally. React Hooks must be called in the exact same order in every component render  react-hooks/rules-of-hooks
// 43:35  error  React Hook "useNextPathname" is called conditionally. React Hooks must be called in the exact same order in every component render         react-hooks/rules-of-hooks
// 44:37  error  React Hook "useReactRouterLocation" is called conditionally. React Hooks must be called in the exact same order in every component render  react-hooks/rules-of-hooks

'use client';

import { usePathname as useNextPathname, useRouter as useNextRouter } from 'next/navigation';
import {

jgcmarins

// https://github.com/vitest-dev/vitest/issues/1575#issuecomment-1439286286
export const setup = () => {
  process.env.TZ = 'UTC';
  process.env.NODE_ENV = 'test';
  // add process.env mocks
};

jgcmarins

check mongod process

sudo lsof -iTCP -sTCP:LISTEN -n -P

kill the process

sudo kill <mongod_pid>

jgcmarins

# serverless-api-gateway.yml
service: central-api-gateway

provider:
  name: aws
  runtime: nodejs14.x
  stage: dev
  region: sua-região

resources:

jgcmarins

/** 

Given an integer array arr of distinct integers and an integer k.
A game will be played between the first two elements of the array (i.e. arr[0] and arr[1]). In each round of the game, we compare arr[0] with arr[1], the larger integer wins and remains at position 0, and the smaller integer moves to the end of the array. The game ends when an integer wins k consecutive rounds.
Return the integer which will win the game.
It is guaranteed that there will be a winner of the game.

Example 1:
Input: arr = [2,1,3,5,4,6,7], k = 2
Output: 5

jgcmarins

const fs = require('fs');
const { PDFDocument, rgb } = require('pdf-lib');
const ExcelJS = require('exceljs');
// Function to convert XLSX to PDF
async function convertXlsxToPdf(inputXlsxPath, outputPdfPath) {
  // Create a new PDF document
  const pdfDoc = await PDFDocument.create();
  // Load the XLSX file
  const workbook = new ExcelJS.Workbook();
  await workbook.xlsx.readFile(inputXlsxPath);