2.4.1.4 Transactions & Concurrency

• Use Cases: Copy trades, syndicate profit distributions, and multi-step operations.

• Sequelize example:

const { Sequelize } = require('sequelize');
const sequelize = require('../config/db');

async function executeCopyTrade(leadTraderId, followerId, tradeData) {
  const transaction = await sequelize.transaction();
  try {
    // Insert trade for lead trader
    const leadTrade = await Trade.create({ ...tradeData, userId: leadTraderId }, { transaction });

    // Replicate trade for follower
    await Trade.create({ ...tradeData, userId: followerId }, { transaction });

    // More logic...
    await transaction.commit();
  } catch (err) {
    await transaction.rollback();
    throw err;
  }
}

This ensures atomicity—either all steps succeed, or none do.