Coldstart

Coldstart is a term used in information technology to describe a situation in which a system has little or no prior data or precomputed state, resulting in higher initial latency or reduced performance until sufficient information or warm state is established.

In recommender systems, the cold-start problem affects new users or new items lacking historical interactions, making it hard to deliver accurate recommendations. Techniques include onboarding questionnaires to elicit preferences, using demographic or item metadata, content-based methods, and hybrid approaches that combine collaborative filtering with side information.

In serverless and cloud computing, cold start latency is the delay incurred when a function is invoked after a period of inactivity, as the platform must allocate a runtime container and load code. Mitigation strategies include provisioned or reserved concurrency, keeping runtimes warm, optimizing startup code, and reducing package size.

In caching and data stores, coldstart refers to the initial population of a cache or the booting of a service, resulting in cache misses or higher latency until frequently accessed data is cached. Pre-warming with historical data or scheduled refreshes helps mitigate.

Across domains, common remedies include leveraging auxiliary data, training on related domains, proactive warming, transfer learning, and designing systems for fast initialization to reduce startup costs without sacrificing accuracy.