An S3-inspired object store: bytes before metadata, a partitioned namespace with cache coherence, then repair, heat, lifecycle and safe change. Three interview boards with explicit assumptions and AWS source boundaries.
Infrastructure, platform and reliability engineers.
Your approach: Use diagrams or prose to explain responsibilities, state, capacity and failure behavior. Show the calculations requested by the question.
Design Object Storage like Amazon S3. An S3-inspired object store: bytes before metadata, a partitioned namespace with cache coherence, then repair, heat, lifecycle and safe change. Three interview boards with explicit assumptions and AWS source boundaries. Work from the scoping questions below. State assumptions for any unspecified load, guarantee or target, then trace your design end to end. Explain one difficult case and a credible alternative; the worked example is a reference, not a required implementation.
Resolve the scoping questions for Object Storage like Amazon S3. Separate stated behavior from assumptions, and identify what is outside your design.
Declare relevant volume, latency, freshness, quality or cost targets with units. Show calculations or an evaluation plan that can test them; unspecified targets are your assumptions, not hidden pass criteria.
Explain how your guarantees hold in a difficult case relevant to this subject. Address: Events? Encryption?
Identify users, required behavior and exclusions. Answer: Scale? Consistency?
Define the information owned by the system and the inputs, outputs and errors at its boundaries. Resolve: Durability? Large objects?
Estimate the dominant workload and resource demand with units and explicit assumptions. For a learned system, also state how quality is measured and what data is available.
Draw or describe the responsibilities needed for Object Storage like Amazon S3. Trace a representative request, event or job from its input to a visible result; identify durable state owners.
Walk through a difficult case step by step, including detection and recovery. Consider: Hot keys and prefixes? Latency? Events? Encryption?
Compare a credible alternative using your chosen workload and guarantees. Explain a remaining risk, a signal to watch and when you would change the design.