index.js

app
  .use('/users', new Router()
    .use('/:username', new Router()
      .get('/', users.show)
      // want to add authorization just for update/delete? sure buddy
      .use(userIsAdminMiddleware)
      .put('/', users.update)
      .del('/', users.destroy)
    )
    .get('/', users.list)
    .post('/', users.create)
  )
  .get('/something', something)

// versus

app
  .get('/users/:username', users.show)
  // want to add authorization just for update/delete? not so easy buddy
  .put('/users/:username', users.update)
  .del('/users/:username', users.destroy)
  .get('/users', users.list)
  .post('/users', users.create)
  .get('/something', something)