ORIGINAL COMPANY-CONTEXT PRACTICE
Preserve inspection results under backpressure
Original practice scenario inspired by KLA Corporation's public business context; this is not a reported interview question or a description of its internal systems. A synthetic inspection pipeline produces large images and small defect metadata. A downstream archive slows during a production burst. Design buffering and prioritization without silently losing the link between images and results.
Written for independent practice using company context; this is not a verified question from a company interview.
A REASONED APPROACH
Model answer.
Give each inspection a durable identity and track image and metadata persistence independently. Prioritization can reduce latency, but an incomplete record must remain visibly incomplete rather than appearing fully archived.
Work through it
- Write metadata and image references to a durable manifest with checksums. Upload large blobs through a bounded queue, and record completion only after integrity verification.
- Set queue limits and explicit overload policies. Preserve critical results while applying documented sampling or rejection rules to optional material, with counters for every loss.
- Make consumers idempotent and reconcile manifests against blobs. Test sustained archive slowness, worker restarts, partial uploads, and recovery without duplicate records.
Tradeoffs to discuss
- Local buffering buys time but requires capacity planning and crash recovery. Blocking production versus discarding optional data is a deliberate operating-policy choice.
Common pitfalls
- Unbounded queues eventually exhaust memory.
- A successful metadata write does not prove its referenced image exists or passed checksum validation.