https://blog.battlefy.com/how-not-to-blow-up-the-production-database-424c162dccc6 attempt #2

apex-legends-score-report.js

type ApexLegendsGameResult = {
  teamID: string,
  placement: number,
  kills: number
};
application.post('/apex-legends/:gameID/report-score', async ({params: {gameID}, body}, res) => {
  const results: ApexLegendsGameResult[] = body;
  await db.collection('apexLegendsGames').updateOne({
    _id: gameID
  }, {
    $set: {
      state: 'completed',
      results
    }
  });
  
  const {tournamentID} = await db.collection('apexLegendsGames').findOne({
    _id: gameID
  });
  const games = await db.collection('apexLegendsGames').find({
    state: 'completed',
    tournamentID
  })
    .toArray();
  let totalKillsByTeamID = 0;
  for (const {results} of games) {
    for (const {teamID, kills} of results) {
      totalKillsByTeamID[teamID] = totalKillsByTeamID[teamID] || {};
      totalKillsByTeamID[teamID] += kills;
    }
  }
  
  const teamIDs = Object.keys(totalKillsByTeamID);
  await db.collection('teams').bulkWrite(teamIDs.map((teamID) => ({
    updateOne: {
      filter: {
        _id: teamID
      },
      update: {
        $set: {
          'stats.totalKills': totalKillsByTeamID[teamID],
          'stats.averageKills': totalKillsByTeamID[teamID] / results.length
        }
      }
    }
  })));
  
  return res.sendStatus(204);
});

tournament-team-stats.js

application.get('/tournament/:tournamentID/team-stats', ({params: {tournamentID}, query: {sort, page}}, res) => {
  const teamsPerPage = 10;
  const pageIndex = page * teamsPerPage;
  const page = db.collection('teams').find({
    tournamentID
  })
    .sort({
      [`stats.${sort}`]: 1
    })
    .skip(pageIndex)
    .limit(teamsPerPage)
    .toArray()
    .map(({name, stats: {totalKills, averageKills}}) => ({
      teamName: name,
      totalKills,
      averageKills
    }));
  
  return res.send(page);
});