The classes and code behind the ad click aggregator: signed click tokens, a redirect that never waits on the log, and a stream counter that de-duplicates and handles late clicks. Tests run all of it.
Data engineers building storage, streaming and processing systems.
Your approach: Use diagrams or prose for data contracts, state ownership, throughput, ordering and recovery where the brief requires them.
Ad Click Aggregator: Low-Level Design. The classes and code behind the ad click aggregator: signed click tokens, a redirect that never waits on the log, and a stream counter that de-duplicates and handles late clicks. Tests run all of it. 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 Ad Click Aggregator: Low-Level Design. 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: How do ingestion, aggregation and persistence interfaces report failure? How would you test recovery between updating a total and acknowledging input?
Identify users, required behavior and exclusions. Answer: What fields identify an ad click, and which fields may change? How are repeated, late and out-of-order clicks interpreted?
Define the information owned by the system and the inputs, outputs and errors at its boundaries. Resolve: Which aggregation windows and advertiser queries are required? How do ingestion, aggregation and persistence interfaces report failure?
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 Ad Click Aggregator: Low-Level Design. 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: How would you test recovery between updating a total and acknowledging input?
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.