Future Apex (@future) Practice Problems

Problem Statement

Write a @future(callout=true) method that fires when a Case is closed and POSTs the case details as JSON to an external REST endpoint.

Requirements

• Must use @future(callout=true)
• Only fire when Status changes to 'Closed' (not already closed)
• Handle HTTP errors (non-200 status codes)

Problem Statement

Implement a Queueable Apex chain that processes large datasets by self-chaining — each execution enqueues the next batch until all records are processed.

This pattern overcomes the 50,000 record SOQL limit by processing in chunks.

Requirements

• Implement Queueable and Database.AllowsCallouts
• Process records in batches of 200
• Self-enqueue when there are more records remaining
• Store offset in the job to track progress

Problem Statement

Publish a Platform Event (Order_Completed__e) from an Apex trigger when an Order record's Status changes to Activated.

Write a subscriber trigger on the platform event that creates a follow-up Task record for the account owner.

Platform Event Fields

• Order_Id__c (Text)
• Account_Id__c (Text)
• Amount__c (Number)

Problem Statement

Implement a Schedulable Apex class that runs nightly to delete Case records that have been Closed for more than 90 days.

Requirements

• Implement the Schedulable interface
• Query Cases where Status = 'Closed' and ClosedDate < 90 days ago
• Delete in bulk (all records at once, not one-by-one)
• Use Database.delete(records, false) to allow partial success

Bonus

Use System.schedule() inside a separate method to register the job for daily execution at midnight.

Problem Statement

Build a Queueable Apex class that makes an HTTP callout and chains to another Queueable on success.

Requirements for ContactSyncQueueable:

• Implement Queueable and Database.AllowsCallouts interfaces
• Constructor accepts List<Id> contactIds and Integer retryCount
• In execute():
  • Query the Contacts by ID (Name, Email, Phone fields)
  • Serialize the contacts to JSON and POST to an external endpoint 'https://api.example.com/contacts/sync'
  • If response status is 200, update each Contact with Sync_Status__c = 'Synced'
  • If not 200 and retryCount < 3, enqueue a new instance of itself with retryCount + 1
  • If not 200 and retryCount >= 3, set Sync_Status__c = 'Failed' on all contacts

Constraints

• No SOQL or DML inside loops
• Use System.enqueueJob() for chaining

Problem Statement

Write an Apex class AccountRatingAsync with a @future method updateRatings(Set<Id> accountIds) that queries each Account and sets:

• AnnualRevenue > 1,000,000 → Rating = "Hot"
• AnnualRevenue >= 100,000 → Rating = "Warm"
• Otherwise → Rating = "Cold"

Key Concept

A @future method runs asynchronously and cannot accept SObject parameters — only primitives and collections of primitives (e.g. Set<Id>).

Problem Statement

Write an Apex class WeeklyLeadDigest that implements Schedulable. In its execute(SchedulableContext ctx) method, query all Leads created in the last 7 days and send a weekly digest email with the count to a sales address.

Requirements

• Implement the Schedulable interface
• Query Leads with CreatedDate >= LAST_N_DAYS:7
• Send an email via Messaging.sendEmail with the lead count in the body

Problem Statement

Write a Queueable Apex class ContactTaggerQueueable that:

1. Accepts a List<Id> of Contact IDs in its constructor
2. In execute(QueueableContext ctx), queries those Contacts along with their Account's Industry
3. Sets Contact.Description to "Industry: " + account.Industry
4. Updates the contacts

Problem Statement

Write a Batch Apex class StaleOpportunityBatch that closes all open Opportunities whose CloseDate is in the past by setting StageName = 'Closed Lost'.

Requirements

• Implement Database.Batchable<SObject>
• start(): return a QueryLocator for open, past-close-date Opps
• execute(): update StageName to "Closed Lost"
• finish(): log completion with System.debug

Problem Statement

Your marketing operations team runs a nightly job to archive leads that have been stuck in Status = 'Open' for more than 30 days without conversion.

Write a Batch Apex class LeadArchiverBatch that:

• Queries all Lead records where Status = 'Open' and CreatedDate <= 30 days ago
• Sets Status = 'Archived' on each lead in the batch
• Logs completion in finish() using System.debug

Requirements

• Implement Database.Batchable<SObject>
• start(): use Database.getQueryLocator
• execute(): bulk-safe — collect changes in a list, single DML update
• finish(): System.debug a completion message

Best Practices

• Use Date.today().addDays(-30) to compute the cutoff date.
• Never perform DML inside a loop — collect and update once per batch chunk.
• Write a test that calls Database.executeBatch() and asserts status changed.

Problem Statement

After an integration runs, your team needs to asynchronously update a custom field Tier__c on each Account based on its AnnualRevenue.

Write a Queueable Apex class AccountTierQueueable that accepts a Set<Id> of account IDs in its constructor and, when executed:

• Queries those accounts for AnnualRevenue
• Sets Tier__c based on revenue: <$50K → 'Bronze', <$250K → 'Silver', <$1M → 'Gold', ≥$1M → 'Platinum'
• Performs a single bulk DML update

Requirements

• Implement Queueable with void execute(QueueableContext ctx)
• Constructor must accept Set<Id> accountIds
• One SOQL query, one DML update inside execute()

Best Practices

• Queueable is preferred over @future when you need to pass SObject collections or chain jobs.
• Enqueue via System.enqueueJob(new AccountTierQueueable(ids)).
• Test with Test.startTest() / stopTest() — the job executes synchronously in tests.

Problem Statement

When leads are inserted via an API integration, you need to asynchronously calculate and store a numeric score on each lead so the process does not slow down the synchronous transaction.

Write an Apex class LeadScoringService with a @future method calculateScore(Set<Id> leadIds) that:

• Queries LeadSource and Industry on the given leads
• Sets a custom field Lead_Score__c using this matrix:

Scoring Matrix

• LeadSource: 'Web' = 10 | 'Phone' = 20 | 'Partner Referral' = 30 | else 5
• Industry: 'Technology' = 20 | 'Finance' = 15 | else 5
• Lead_Score__c = LeadSource score + Industry score

Best Practices

• @future methods must be static, return void, and accept only primitive types or collections of primitives.
• One SOQL query and one DML update inside the method.
• Call from a trigger using if (!System.isFuture() && !System.isBatch()) guard.

Problem Statement

Write an Apex class ContactAddressSyncUtil with a @future method syncMailingAddressFromAccount(Set<Id> accountIds) that copies the Account's billing address to all its Contacts' mailing address fields.

Requirements

• Method must be @future, public static void.
• Parameters must be primitives or collections of primitives — use Set<Id>.
• Guard against null / empty input at the top.
• One SOQL for Accounts, one for Contacts — both outside any loop.
• Build a Map<Id, Account> to avoid nested loops.
• Copy: BillingCity → MailingCity, BillingState → MailingState, BillingPostalCode → MailingPostalCode, BillingCountry → MailingCountry.
• One bulk DML update, guarded by isEmpty().

Best Practices

• @future methods cannot accept SObject parameters — use Set<Id>.
• Two SOQLs, zero inside loops — governor-safe.
• Use a Map keyed by Account Id for O(1) lookup in the Contact loop.

Problem Statement

Write LeadEnrichmentUtil with a @future(callout=true) method enrichLeadFromExternalAPI(Id leadId) that calls an external REST API to enrich a Lead's company data.

Requirements

• Annotation: @future(callout=true)
• Guard: return early if leadId == null.
• Query the Lead by Id (LIMIT 1).
• Build an HttpRequest: endpoint, method GET, Accept header, timeout 10 s.
• Call new Http().send(req) inside a try-catch(Exception e).
• If status code is 200: parse JSON with JSON.deserializeUntyped, set Company, Industry, LeadSource = 'API Enriched', then update the Lead.
• Log non-200 responses and exceptions with System.debug.

Best Practices

• Always wrap callouts in try-catch(Exception e) — network can fail.
• Check getStatusCode() == 200 before trusting the body.
• Set a timeout: req.setTimeout(10000) — prevents governor limit hits.

Problem Statement

Write LeadScoreResetUtil with a @future method resetLeadScoresForCampaign(Set<Id> campaignIds) that resets Lead_Score__c to 0 for all Leads who are members of the given Campaigns.

Requirements

• @future annotation; parameter must be Set<Id>.
• Guard: return early if campaignIds is null or empty.
• Query CampaignMember to find Lead Ids.
• Build a Set<Id> leadIds, guard empty, then query Lead.
• Reset Lead_Score__c = 0 on all found Leads.
• Wrap the final update in try-catch(DmlException e).

Best Practices

• Two-step query pattern: CampaignMember → Lead Ids → Lead records.
• Check leadIds.isEmpty() before the second SOQL to avoid empty IN clause.
• Never put SOQL or DML inside a for loop.

Problem Statement

Write AccountCreditCheckUtil with a @future(callout=true) method runCreditCheck(Id accountId) that calls an external credit API and updates Credit_Score__c and Credit_Status__c on Account.

Scoring Logic

• creditScore ≥ 700 → Credit_Status__c = 'Approved'
• 500 – 699 → 'Review'
• < 500 → 'Declined'

Requirements

• Use @future(callout=true); guard null accountId.
• Build POST request with Content-Type and Accept headers; timeout 15 s.
• Catch CalloutException separately — set Credit_Status__c = 'Callout Error' and return early.
• Check status code 200; parse JSON; handle non-200 by setting Credit_Status__c = 'API Error'.
• Wrap JSON parsing in a second try-catch(Exception e).