SALESFORCE APEX WEBHOOK SYNC IMPLEMENTATION:

TRIGGER DEFINITION
   trigger AccountSyncWebhook on Account (after insert, after update) {
     List<Account> changedAccounts = new List<Account>();
     
     for (Account acc : Trigger.new) {
       Account oldAcc = Trigger.oldMap.get(acc.Id);
       if (oldAcc == null || hasRelevantChanges(acc, oldAcc)) {
         changedAccounts.add(acc);
       }
     }
     
     if (!changedAccounts.isEmpty()) {
       AccountWebhookDispatcher.enqueueSync(changedAccounts);
     }
   }

QUEUEABLE BATCH HANDLER (respects governor limits)
   public class AccountWebhookDispatcher implements Queueable, Database.AllowsCallouts {
     static void enqueueSync(List<Account> accounts) {
       System.enqueueJob(new AccountWebhookDispatcher(accounts));
     }
     
     public void execute(QueueableContext ctx) {
       for (Account acc : accounts) {
         Map<String, Object> payload = new Map<String, Object>{
           'id' => acc.Id,
           'name' => acc.Name,
           'industry' => acc.Industry,
           'webhook_timestamp' => DateTime.now().getTime()
         };
         
         HttpRequest req = new HttpRequest();
         req.setEndpoint('https://api.example.com/webhooks/account-sync');
         req.setMethod('POST');
         req.setBody(JSON.serialize(payload));
         
         Http http = new Http();
         HttpResponse res = http.send(req);
         if (res.getStatusCode() >= 400) {
           logWebhookFailure(acc.Id, res.getBody());
         }
       }
     }
   }

TEST CLASS (required for deployment)
   @isTest static void testAccountChangeTriggersWebhook() {
     Test.setMock(HttpCalloutMock.class, new WebhookMockResponse());
     Account testAcc = new Account(Name='Test Co', Industry='Tech');
     insert testAcc;
     // Assert webhook was called with correct payload
   }

GOVERNOR LIMITS STRATEGY
   - Batch changes in Queueable (async job avoids callout limits)
   - Max 1 webhook callout per account update
   - Retry logic with exponential backoff (future method)