Prepare the data
Collect user–restaurant interactions with timestamps and optional metadata; deduplicate and split into train and test by time to avoid leakage.
Recommend restaurants to users. Weigh similarity among users.
Restaurant recommendation uses behaviour (ratings or visits), item metadata and context to suggest places a user may like. Common challenges are data sparsity, popularity bias, temporal drift and cold-start items or users; evaluation requires ranking metrics (Precision@K, Recall@K, NDCG) and offline–online validation.
Learning concept · Not a validated service
Restaurant recommendation uses behaviour (ratings or visits), item metadata and context to suggest places a user may like. Common challenges are data sparsity, popularity bias, temporal drift and cold-start items or users; evaluation requires ranking metrics (Precision@K, Recall@K, NDCG) and offline–online validation.
A proposed application: personalise suggestions for a local dining app to help users discover restaurants they may like, while surfacing explanations and allowing user feedback. The supplied starter does not implement the production components of this extension.
Collect user–restaurant interactions with timestamps and optional metadata; deduplicate and split into train and test by time to avoid leakage.
Create a user–item matrix and compute user–user similarity (cosine) to score unseen restaurants from nearest neighbours.
Measure Precision@K, Recall@K and NDCG on held-out interactions and inspect cold-start and sparse-user cases.
Add caching, fallback rules, rate limits and a feedback capture mechanism; monitor coverage and online engagement.
The supplied starter creates a small synthetic ratings DataFrame, pivots it into a user–item matrix, computes cosine similarity between users, finds the nearest neighbour for a target user, and recommends that neighbour's unseen items sorted by neighbour rating.
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,
)
target_user = "user_1"
neighbor = user_similarity[target_user].drop(target_user).idxmax()
unseen_items = matrix.loc[target_user][matrix.loc[target_user] == 0].index
scores = matrix.loc[neighbor, unseen_items].sort_values(ascending=False)The code uses a tiny hand-crafted ratings table rather than real restaurant data, includes no item metadata or contextual signals, implements only a single neighbour-based score with no ranking metrics or train/test evaluation, and does not address cold-start, temporal splitting or production serving.
A proposed extension: replace the toy ratings with a real restaurant interaction log, add item metadata (cuisine, location), compute top-K ranked lists with NDCG evaluation, and surface simple explanations (neighbour-based) in a lightweight API.
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.