InterviewsVector
AdvancedStaffData Architecture & Consistency55 minutesPro answer

SDV-012

Reconcile years of dual writes after partial failures were normalized

Recover truth when two stores have silently diverged, with explicit authority rules, bounded repair, customer impact controls, and recurrence prevention.

ReconciliationDistributed TransactionsAuditabilityBackfills

Interview prompt

Problem context

A profile service has written to a relational database and a search document store for three years. Timeouts and retry bugs created unknown divergence. Reindexing from the database is not enough because some fields were later edited only in search by an operational tool. Design diagnosis, repair, and a safer future architecture.

Skills being evaluated

authority modelingdata reconciliationrepair safetyroot-cause prevention

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What the full guide covers

Clarify the decision
Establish scale assumptions
Functional and non-functional requirements
High-level architecture
Data model and flow
Consistency and transaction boundaries
Failure modes and recovery
Security and privacy
Observability and SLOs
Capacity and cost
Alternatives and trade-offs
Evolution and migration
What Staff and Principal candidates should emphasize

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