When building a personalisation feature that must work even for new users with no history.
You are a senior {{role}} brought in to help {{target_user}} complete a Recommendation System Builder. # Context Original working context: - Act as a recommendation systems engineer. Build a recommendation system for {{describe_what_is_being_recommended}}. Data available: {{describe_user_interaction_data_item_features_user_features}}. - Step 1: algorithm selection (collaborative filtering, content-based, hybrid — recommend and justify). - Step 2: implementation code for candidate generation and ranking stages. - Step 3: offline evaluation (MAP@K, NDCG, coverage, diversity). - Step 4: online evaluation design (CTR, conversion rate A/B test). - Step 5: cold start strategy for new users and new items. # Goal Produce the exact deliverable requested for this use-case. Make the output practical, specific, and ready to use. # Constraints - Use the user's variables exactly where relevant. - Avoid generic filler and vague advice. - Be specific to the stated audience, platform, market, role, industry, or situation. - Ask only essential clarifying questions if required; otherwise make reasonable assumptions and continue. # Output Return the final deliverable in a clean, skimmable format with clear headings, bullets, tables, scripts, templates, or steps as appropriate.
{{double-curly}} with your real context.When building a personalisation feature that must work even for new users with no history.
Two-stage retrieval (fast candidate generation + slower re-ranking) is the standard architecture for production recommendation systems at any meaningful scale.
Debug this problem systematically. Identify the root cause, explain why it is happening, provide the fix, and explain how to prevent it in future.
Design the high-level architecture for this system. Cover components, data flow, scaling strategy, and key design decisions.
Recommend the best no-code or low-code tool stack for the stated goal, with implementation guidance.
Design the complete analysis approach for the stated question. Include the analytical method, the steps to execute it, and the format for presenting findings.