https://medium.com/yld-blog/reduce-bloat-of-your-lambdas-5121169c15f8

serverless.js

const { name: service } = require('./package.json');

const { INDIVIDUALLY = '0', NCC = '0' } = process.env;
const IS_INDIVIDUALLY = Boolean(JSON.parse(INDIVIDUALLY));
const IS_NCC = Boolean(JSON.parse(NCC));

module.exports = {
  service,
  plugins: [IS_NCC && 'serverless-plugin-ncc'].filter(Boolean),
  provider: {
    name: 'aws',
    runtime: 'nodejs10.x',
    // eslint-disable-next-line no-template-curly-in-string
    region: '${env:AWS_REGION, "eu-west-3"}',
    // eslint-disable-next-line no-template-curly-in-string
    stage: '${opt:stage, "development"}',
    environment: {
      // eslint-disable-next-line no-template-curly-in-string
      NODE_ENV: '${env:NODE_ENV, "development"}',
    },
  },
  package: {
    individually: IS_INDIVIDUALLY,
    excludeDevDependencies: !IS_NCC,
  },
  custom: {
    ncc: {
      // we can ignore aws-sdk because the node runtime in lambda automatically include is
      externals: ['aws-sdk/clients/s3'],
    },
  },
  functions: {
    GraphQL: {
      handler: 'graphql.handler',
      events: [
        {
          http: {
            path: '/graphql',
            method: 'POST',
          },
        },
      ],
    },
    Playground: {
      handler: 'playground.handler',
      events: [
        {
          http: {
            path: '/playground',
            method: 'GET',
          },
        },
      ],
    },
    Upload: {
      handler: 'upload.handler',
      events: [
        {
          http: {
            path: '/upload',
            method: 'POST',
          },
        },
      ],
    },
  },
};