Design (LLD) Online Voting System - Machine CodingSubhahu Jain·Oct 23, 2022·9 min readTable of contentsCode⚠️ Issues in Above Design1️⃣ Vote Casting Is NOT Atomic (Critical Integrity Violation)ProblemLLD IssueConcurrency IssueResultInterview Keyword 🚨Solution2️⃣ hasVoted Flag Is UnsafeProblemConcurrency IssueResultInterview ExpectationSolution3️⃣ Votes Are Stored in Memory (Fatal Design Flaw)ProblemLLD IssueConcurrency IssueInterview Verdict ❌Solution4️⃣ Voter Identity Is Directly Linked to Vote (Privacy Violation)ProblemLLD IssueSecurity & Privacy IssueInterview ExpectationSolution5️⃣ Password Handling Is InsecureProblemLLD IssueConcurrency + Security RiskInterview Red Flag 🚨Solution6️⃣ HashMap & ArrayList Are UnsafeProblemConcurrency IssueReal-World ScenarioInterview ExpectationSolution7️⃣ Observer Pattern Is Blocking & DangerousProblemLLD IssueConcurrency RiskInterview KeywordSolution8️⃣ Encryption Strategy Is Fake EncryptionProblemLLD IssueSecurity IssueInterview ExpectationSolution9️⃣ No Idempotency ProtectionProblemConcurrency IssueInterview InsightSolution🔟 No Audit Log / VerifiabilityMissing EntirelyLLD IssueInterview VerdictSolutionJavaScriptPythonGeneral ProgrammingProgramming Blogs
