List<cxsrec__cxsCandidate__c> candidates = [SELECT Id, Formula_Expiry_Privacy_Agreement__c FROM cxsrec__cxsCandidate__c WHERE cxsrec__E_mail_address__c LIKE 'anontest%'];

List<Task> taskList = new List<Task>();
List<ConnectApi.BatchInput> batchInputs = new List<ConnectApi.BatchInput>();
List<Attachment> attachmentList = new List<Attachment>();

for(cxsrec__cxsCandidate__c candidate : candidates) {
    taskList.add(new Task(Subject = 'Testaufgabe soll weg', Description = 'Das sollte nicht mehr hier stehen', Status = 'Open', WhatId = candidate.Id));
    taskList.add(new Task(Subject = 'Testaufgabe soll anonymisiert werden', Description = 'Das sollte nicht mehr hier stehen', Status = 'Completed',WhatId = candidate.Id));

    Attachment att=new Attachment();
    att.Body=Blob.valueOf('Sollte weg');
    att.Name='Note_' + System.now().format('yyyy_MM_dd_hh_mm_ss') + '.txt';
    att.ParentId=candidate.Id;
    attachmentList.add(att);

    ConnectApi.FeedItemInput input = new ConnectApi.FeedItemInput();
    input.subjectId = candidate.Id;
    input.visibility = ConnectApi.FeedItemVisibilityType.AllUsers;

    ConnectApi.MessageBodyInput bodyInput = new ConnectApi.MessageBodyInput();
    bodyInput.messageSegments = new List<ConnectApi.MessageSegmentInput>();

    ConnectApi.TextSegmentInput textSegment = new ConnectApi.TextSegmentInput();
    textSegment.text = 'Test.';

    bodyInput.messageSegments.add(textSegment);
    input.body = bodyInput;

    ConnectApi.BatchInput batchInput = new ConnectApi.BatchInput(input);
    batchInputs.add(batchInput);
}

insert attachmentList;

ConnectApi.ChatterFeeds.postFeedElementBatch(null, batchInputs);

insert taskList;