Core to Deep Dive
Review context windows, durable memory, retrieval, freshness, summarization, and cross-session state design.
Depth
Showing 4 of 4 questions
Short answer
Short-term memory supports the active task, long-term memory stores durable facts or preferences across sessions, and episodic memory records specific past interactions or outcomes. They differ in retention, retrieval, structure, and privacy expectations.
Interview-ready answer
I treat short-term memory as a bounded working set, often the recent turns plus summarized state. Long-term memory contains carefully selected durable information such as preferences or stable facts. Episodic memory preserves events with time, context, action, and outcome so similar past situations can be retrieved. In production these stores need separate ranking, freshness, consent, deletion, and tenant-isolation policies.
Common mistakes
Short answer
Store information only when it has future utility, sufficient confidence, user permission, and a defined retention policy. Prefer explicit user preferences and verified outcomes over speculative model summaries or transient conversation details.
Interview-ready answer
I score candidates on usefulness, durability, confidence, sensitivity, and duplication. Important facts carry provenance, timestamps, ownership, and expiration, and users should be able to inspect or delete durable personal memory. I also separate raw events from derived summaries so a future correction can invalidate dependent memory rather than leaving stale conclusions embedded in the system.
Common mistakes
Short answer
Use relevance thresholds, freshness weighting, provenance, expiration, deduplication, and contradiction handling. Retrieved memories should be presented as evidence with confidence and time context, not inserted as unquestioned instructions.
Interview-ready answer
I combine semantic relevance with metadata filters for user, task, recency, source, and status. A reranker can balance relevance against freshness, while TTLs and explicit invalidation remove known stale entries. Contradictory memories should be surfaced or reconciled rather than silently selecting one. Evaluation should include stale and adversarial memory cases because clean benchmark retrieval can hide serious production failures.
Common mistakes
Short answer
Use separate stores for verified profile facts, user preferences, task state, and timestamped episodes. Gate writes through consent and confidence rules, retrieve with strict user isolation, and provide inspection, correction, deletion, and expiration controls.
Interview-ready answer
I would capture candidate memories after each session, classify sensitivity and type, deduplicate them, and require explicit confirmation for uncertain or sensitive facts. Durable records include provenance, version, timestamps, confidence, and deletion state. Retrieval is scoped to the authenticated user and task, then reranked for relevance and freshness before a compact memory view enters the prompt. Auditing and user controls are first-class because memory errors accumulate across sessions.
Common mistakes