Use Heroku's release feature to deploy Typescript NodeJS sourcemaps to Sentry. So you can properly debug transpiled Typescript files!

index.ts

// After your import's

if (process.env.NODE_ENV === 'production') {
  Sentry.init({
    dsn: process.env.SENTRY_DSN,
    environment: 'production',
    release: process.env.HEROKU_SLUG_COMMIT,
    integrations: [
      new Sentry.Integrations.RewriteFrames({
        root: __dirname
      })
    ]
  });
}

Procfile

release: bash ./release-sentry.sh
web: npm start

release-sentry.sh

#!/bin/sh
npx sentry-cli releases --org $SENTRY_ORG --project $SENTRY_PROJECT files $HEROKU_SLUG_COMMIT upload-sourcemaps dist/ --no-rewrite --validate

tsconfig.json

{
  "compilerOptions": {
    "target": "es6",
    "module": "commonjs",
    "allowJs": true,
    "moduleResolution": "node",
    "outDir": "dist"
  },
  "include": [
    "./src/**/*"
  ]
}

tsconfig.production.json

{
  "extends": "./tsconfig",
  "compilerOptions": {
    "sourceMap": true,
    "inlineSources": true,
    "sourceRoot": "/"
  }
}