Prepare interaction data
Collect user–item ratings or implicit events, pivot into a user–item matrix and handle missing values before splitting into train and test.
Deep learning for recommendations. Score candidate items.
Recommender systems predict items a user may like from past interactions, item metadata and context. Common error modes include cold-start users and items, popularity bias, and sparse feedback; measuring ranking metrics such as Precision@K and NDCG helps quantify performance.
Learning concept · Not a validated service
Recommender systems predict items a user may like from past interactions, item metadata and context. Common error modes include cold-start users and items, popularity bias, and sparse feedback; measuring ranking metrics such as Precision@K and NDCG helps quantify performance.
A proposed extension: personalise retail or media catalogues to surface items a returning user may like, while keeping a human-in-the-loop for business rules and diversity to avoid over-personalising. This starter does not implement the deep models or production features required for live systems.
Collect user–item ratings or implicit events, pivot into a user–item matrix and handle missing values before splitting into train and test.
Implement a simple user-based collaborative-filtering baseline using cosine similarity to set an initial performance point.
Report ranking metrics such as Precision@K and NDCG on held-out interactions and inspect failure modes like cold-starts and popularity bias.
Propose replacing the baseline with a learned model (e.g. matrix factorisation, neural collaborative filtering) and define inputs, loss and online serving requirements.
The supplied starter builds a tiny, hard-coded user–item rating table, creates a user–item pivot matrix, computes cosine similarity between users, chooses the nearest neighbour for a target user and recommends that neighbour's highest-rated unseen items. It does not use deep learning or train any neural model.
matrix = ratings.pivot_table(index="user", columns="item", values="rating").fillna(0)
user_similarity = pd.DataFrame(
cosine_similarity(matrix),
index=matrix.index,
columns=matrix.index,
)This starter uses a six-user, five-item toy table and a user–user nearest-neighbour lookup; it does not implement deep learning, train latent-factor models, nor evaluate standard ranking metrics on a realistic dataset. Results from this toy data do not reflect production performance.
A proposed extension: replace the neighbour-based scorer with a neural collaborative-filtering model that learns user and item embeddings from interaction data and predicts scores for ranking.
This is a potential application pathway, not a delivered product. The supplied starter does not implement this service or validate it with real users.
Networkers Home runs this topic inside its AI Engineer Course, with placement support and hands-on labs.