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Problems
Every problem in the roadmap, in curriculum order.
0
of 188 solved
0 attempted
0%
Problem of the day
GraphSAGE Mean Aggregation
Medium
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All topics
Linear Algebra
Calculus
Probability and Statistics
Machine Learning
Evaluation Metrics
Unsupervised Learning
Deep Learning
Natural Language Processing
Computer Vision
PyTorch
Information Theory
Optimisation
Ensembles and Boosting
Probabilistic Models
Reinforcement Learning
Recommender Systems
Time Series
MLOps and Data Processing
Generative Models
Graph Neural Networks
Transformers and LLMs
All
Easy
Medium
Hard
All
Solved
Attempted
Not started
188 problems
Linear Algebra
0/12 solved
Guide →
01
Matrix Multiplication
numpy
matrices
Easy
02
Cosine Similarity
numpy
vectors
Easy
03
Orthogonal Projection
numpy
vectors
Easy
04
Row Echelon Form
numpy
elimination
Medium
05
Matrix Inverse by Gauss-Jordan
numpy
elimination
Medium
06
Eigenvalues of a 2x2 Matrix
numpy
eigen
Easy
07
Determinant by Elimination
numpy
elimination
Medium
08
Gram-Schmidt Orthonormalisation
numpy
orthogonalization
Hard
09
Power Iteration
numpy
eigen
iterative
Medium
10
LU Decomposition
numpy
elimination
factorization
Medium
11
Low Rank Image Compression
PyTorch
torch
svd
low-rank
compression
Medium
12
Tune Ridge With a Hypergradient
PyTorch
torch
linear-systems
autograd
regularisation
Hard
Calculus
0/7 solved
Guide →
13
Numerical Gradient
numpy
gradients
Easy
14
Chain Rule Through a Small Network
numpy
backprop
Medium
15
Gradient Descent in One Dimension
optimization
Easy
16
Softmax Jacobian
numpy
backprop
Medium
17
Numerical Hessian
numpy
gradients
second-order
Medium
18
Hessian Vector Products
PyTorch
torch
autograd
hessian
second-order
Medium
19
Custom Autograd Function
PyTorch
torch
autograd
numerical-stability
gradients
Medium
Probability and Statistics
0/10 solved
Guide →
20
Normal Distribution PDF
numpy
distributions
Easy
21
Binomial Probability
distributions
combinatorics
Easy
22
Bayes' Theorem
probability
Easy
23
Covariance Matrix
numpy
statistics
Easy
24
KL Divergence
numpy
information-theory
Medium
25
Shannon Entropy
numpy
information-theory
Easy
26
Poisson Distribution
distributions
Easy
27
Welch's t-Test Statistic
numpy
statistics
hypothesis-testing
Medium
28
Monte Carlo Gradient Estimators
PyTorch
torch
distributions
monte-carlo
reparameterisation
Medium
29
Predict the Noise Too
PyTorch
torch
distributions
likelihood
uncertainty
Hard
Machine Learning
0/15 solved
Guide →
30
Feature Scaling
numpy
preprocessing
Easy
31
Train Test Split
numpy
validation
Easy
32
Linear Regression by Normal Equation
numpy
regression
linear-algebra
Easy
33
Linear Regression by Gradient Descent
numpy
regression
optimization
Medium
34
Ridge Regression
numpy
regression
regularization
Medium
35
Logistic Regression by Gradient Descent
numpy
classification
optimization
Medium
36
K Nearest Neighbours
numpy
classification
Medium
37
Best Gini Split
numpy
trees
Medium
38
K-Fold Cross Validation
numpy
validation
Easy
39
One-Hot Encoding
numpy
preprocessing
Easy
40
Gaussian Naive Bayes
numpy
classification
probability
Hard
41
Linear SVM with Hinge Loss
numpy
classification
optimization
Hard
42
Lasso by Coordinate Descent
numpy
regression
regularization
optimization
Hard
43
Softmax Regression on Digits
PyTorch
torch
classification
dataloader
Medium
44
Poisson Regression by Maximum Likelihood
PyTorch
torch
regression
distributions
Medium
Evaluation Metrics
0/11 solved
Guide →
45
Confusion Matrix
numpy
metrics
Easy
46
Precision, Recall and F1
numpy
evaluation
Easy
47
R Squared
numpy
metrics
regression
Easy
48
Jaccard and Dice Scores
numpy
metrics
segmentation
Easy
49
ROC AUC
numpy
metrics
ranking
Hard
50
Top-K Accuracy
numpy
metrics
Easy
51
Macro and Micro F1
numpy
metrics
Medium
52
Average Precision
numpy
metrics
ranking
Medium
53
Expected Calibration Error
numpy
metrics
calibration
Medium
54
Temperature Scaling
PyTorch
torch
calibration
evaluation
Medium
55
An Honest Evaluation Loop
PyTorch
torch
evaluation
dataloader
Medium
Unsupervised Learning
0/7 solved
Guide →
56
K-Means Clustering
numpy
clustering
Medium
57
Principal Component Analysis
numpy
linear-algebra
Medium
58
Silhouette Score
numpy
clustering
evaluation
Medium
59
DBSCAN
numpy
clustering
Hard
60
Single Linkage Clustering
numpy
clustering
hierarchical
Medium
61
K-Means with Batched Restarts
PyTorch
torch
clustering
k-means
vectorisation
Hard
62
Linear Autoencoder Meets PCA
PyTorch
torch
autoencoder
pca
nn-module
Medium
Deep Learning
0/16 solved
Guide →
63
Activation Functions
numpy
activation
Easy
64
Softmax
numpy
activation
Easy
65
Cross Entropy Loss
numpy
loss
Easy
66
Single Neuron with Backpropagation
numpy
backprop
training
Medium
67
Backprop Through a Dense Layer
numpy
backprop
autograd
Medium
68
Layer Normalisation
numpy
transformers
Easy
69
Adam Optimizer
numpy
optimization
Medium
70
Scaled Dot Product Attention
numpy
transformers
attention
Hard
71
Multi-Head Attention
numpy
transformers
attention
Hard
72
Gradient Clipping by Global Norm
numpy
training
Easy
73
Batch Normalisation
numpy
normalization
Medium
74
Recurrent Cell Forward Pass
numpy
rnn
sequences
Medium
75
LSTM Cell Forward Pass
numpy
rnn
sequences
Hard
76
Cross Entropy with Label Smoothing
numpy
loss
regularization
Easy
77
Custom Autograd Function: SiLU
PyTorch
torch
autograd
backprop
activations
Medium
78
Batch Norm as an nn.Module
PyTorch
torch
normalisation
nn-module
Hard
Natural Language Processing
0/9 solved
Guide →
79
Character Tokenizer
nlp
tokenization
Easy
80
TF-IDF
numpy
nlp
features
Medium
81
Sinusoidal Positional Encoding
numpy
transformers
Medium
82
BLEU Score
nlp
metrics
Medium
83
Byte Pair Encoding
nlp
tokenization
Hard
84
Skip-Gram Training Pairs
nlp
embeddings
word2vec
Easy
85
Levenshtein Edit Distance
nlp
dynamic-programming
strings
Medium
86
Classify Padded Text with Masked Mean Pooling
PyTorch
torch
embeddings
masking
classification
Medium
87
Word2Vec with Negative Sampling
PyTorch
torch
embeddings
word2vec
contrastive
Hard
Computer Vision
0/8 solved
Guide →
88
Intersection over Union
numpy
detection
Easy
89
Max Pooling 2D
numpy
cnn
Easy
90
Conv2D Forward Pass
numpy
cnn
Medium
91
Non-Maximum Suppression
numpy
detection
Medium
92
Multi-Channel Convolution
numpy
cnn
Hard
93
Sobel Edge Magnitude
numpy
filters
edges
Easy
94
A Small CNN for Digits
PyTorch
torch
cnn
convolution
classification
Medium
95
Convolution with Unfold
PyTorch
torch
convolution
im2col
einsum
Hard
PyTorch
0/5 solved
Guide →
96
Autograd
PyTorch
torch
gradients
Easy
97
Train a Linear Model
PyTorch
torch
training
optimization
Medium
98
Train a Classifier
PyTorch
torch
training
classification
Hard
99
Mini-batch Training with DataLoader
PyTorch
torch
dataloader
training
classification
Medium
100
Gradient Accumulation
PyTorch
torch
training
gradients
hooks
Medium
Information Theory
0/8 solved
Guide →
101
Perplexity
numpy
information-theory
language-models
Easy
102
Conditional Entropy
numpy
information-theory
Easy
103
Mutual Information
numpy
information-theory
Medium
104
Jensen-Shannon Divergence
numpy
information-theory
Easy
105
Information Gain of a Split
numpy
information-theory
trees
Easy
106
Huffman Code Lengths
information-theory
compression
greedy
Medium
107
Label Smoothing Cross Entropy
PyTorch
torch
cross-entropy
masking
loss-functions
Medium
108
Estimate Mutual Information
PyTorch
torch
mutual-information
contrastive
training
Hard
Optimisation
0/8 solved
Guide →
109
SGD with Momentum
numpy
optimization
Easy
110
Nesterov Momentum
numpy
optimization
Medium
111
RMSProp
numpy
optimization
Easy
112
Warmup and Cosine Decay
optimization
schedules
Easy
113
Backtracking Line Search
numpy
optimization
Medium
114
Newton's Method for Minimisation
numpy
optimization
linear-algebra
Medium
115
AdamW as a torch Optimizer
PyTorch
torch
optimization
adam
Hard
116
L-BFGS with a Closure
PyTorch
torch
optimization
quasi-newton
Medium
Ensembles and Boosting
0/7 solved
Guide →
117
Majority Vote
numpy
ensembles
classification
Easy
118
Weighted Decision Stump
numpy
ensembles
trees
Medium
119
One Round of AdaBoost
numpy
ensembles
boosting
Medium
120
Out-of-Bag Error
numpy
ensembles
bagging
validation
Medium
121
Gradient Boosting with Stumps
numpy
ensembles
boosting
regression
Hard
122
Deep Ensemble with torch.func
PyTorch
torch
ensembles
vmap
uncertainty
Medium
123
Gradient Boosting with Any Loss
PyTorch
torch
boosting
autograd
trees
Hard
Probabilistic Models
0/8 solved
Guide →
124
Stationary Distribution of a Markov Chain
numpy
markov-chains
eigen
Easy
125
HMM Forward Algorithm
numpy
hmm
dynamic-programming
Medium
126
Viterbi Decoding
numpy
hmm
dynamic-programming
Hard
127
Gaussian Mixture E-Step
numpy
gmm
em
clustering
Medium
128
Gaussian Mixture M-Step
numpy
gmm
em
clustering
Medium
129
Bayesian Linear Regression
numpy
bayesian
regression
Medium
130
Gaussian Mixture with torch.distributions
PyTorch
torch
distributions
mixture-models
maximum-likelihood
Medium
131
Variational Bayes with the Reparameterisation Trick
PyTorch
torch
variational-inference
bayesian
distributions
Hard
Reinforcement Learning
0/8 solved
Guide →
132
Discounted Returns
numpy
rl
Easy
133
Q-Learning Update
numpy
rl
q-learning
Easy
134
Policy Evaluation
numpy
rl
dynamic-programming
Medium
135
Value Iteration
numpy
rl
dynamic-programming
Medium
136
Generalised Advantage Estimation
numpy
rl
policy-gradient
Medium
137
UCB Action Selection
numpy
rl
bandits
Easy
138
REINFORCE with a Baseline
PyTorch
torch
rl
policy-gradient
distributions
Medium
139
DQN Loss and Target Network
PyTorch
torch
rl
q-learning
dqn
Hard
Recommender Systems
0/8 solved
Guide →
140
Precision and Recall at K
numpy
recsys
metrics
ranking
Easy
141
NDCG at K
numpy
recsys
metrics
ranking
Medium
142
Item-Based Collaborative Filtering
numpy
recsys
similarity
Medium
143
Matrix Factorisation by SGD
numpy
recsys
optimization
Hard
144
Alternating Least Squares Step
numpy
recsys
linear-algebra
Medium
145
Bayesian Personalised Ranking Loss
numpy
recsys
loss
ranking
Easy
146
Matrix Factorisation with Embeddings
PyTorch
torch
embeddings
collaborative-filtering
training
Medium
147
Two-Tower Retrieval with In-Batch Negatives
PyTorch
torch
retrieval
contrastive
training
Hard
Time Series
0/8 solved
Guide →
148
Moving Average
numpy
time-series
smoothing
Easy
149
Sliding Windows for Forecasting
numpy
time-series
preprocessing
Easy
150
Autocorrelation Function
numpy
time-series
statistics
Easy
151
Holt's Linear Trend Forecast
numpy
time-series
forecasting
Medium
152
Autoregressive Forecast
numpy
time-series
regression
Medium
153
Dynamic Time Warping
numpy
time-series
dynamic-programming
Medium
154
Causal Dilated Convolution
PyTorch
torch
convolution
autograd
sequence-models
Medium
155
Forecast with an LSTM
PyTorch
torch
lstm
forecasting
training
Medium
MLOps and Data Processing
0/8 solved
Guide →
156
Impute Missing Values
numpy
preprocessing
data-cleaning
Easy
157
Stratified Train Test Split
numpy
validation
preprocessing
Medium
158
Smoothed Target Encoding
numpy
preprocessing
categorical
Medium
159
Population Stability Index
numpy
monitoring
drift
Medium
160
Kolmogorov-Smirnov Statistic
numpy
monitoring
drift
statistics
Medium
161
Int8 Weight Quantisation
numpy
deployment
quantization
Medium
162
Length-Bucketed DataLoader
PyTorch
torch
dataloader
padding
data-pipelines
Medium
163
Resume Training Exactly
PyTorch
torch
checkpointing
reproducibility
training
Medium
Generative Models
0/8 solved
Guide →
164
VAE Reparameterisation Trick
numpy
vae
generative
Easy
165
VAE Loss (Negative ELBO)
numpy
vae
loss
generative
Medium
166
GAN Losses
numpy
gan
loss
generative
Easy
167
Diffusion Forward Process
numpy
diffusion
generative
Medium
168
DDPM Reverse Step
numpy
diffusion
generative
Hard
169
Normalising Flow Log Likelihood
numpy
normalizing-flows
generative
Medium
170
Train a VAE on Digits
PyTorch
torch
vae
generative
distributions
Hard
171
Affine Coupling Flow
PyTorch
torch
normalising-flows
generative
autograd
Hard
Graph Neural Networks
0/8 solved
Guide →
172
Normalised Adjacency Matrix
numpy
graphs
gnn
Easy
173
Graph Convolution Layer
numpy
graphs
gnn
Medium
174
GraphSAGE Mean Aggregation
numpy
graphs
gnn
Medium
175
Graph Attention Coefficients
numpy
graphs
gnn
attention
Hard
176
Graph Readout
numpy
graphs
gnn
pooling
Easy
177
PageRank
numpy
graphs
markov-chains
Medium
178
Semi-Supervised GCN
PyTorch
torch
graphs
gnn
masking
Medium
179
Batched Graph Classification
PyTorch
torch
graphs
gnn
batching
scatter
Hard
Transformers and LLMs
0/9 solved
Guide →
180
RMSNorm
numpy
transformers
normalization
Easy
181
Causal Self-Attention
numpy
transformers
attention
Medium
182
Rotary Position Embeddings
numpy
transformers
positional-encoding
Medium
183
SwiGLU Feed-Forward Block
numpy
transformers
activation
Easy
184
Attention with a KV Cache
numpy
transformers
attention
inference
Medium
185
Top-p (Nucleus) Filtering
numpy
llm
sampling
decoding
Medium
186
LoRA Linear Layer
numpy
llm
fine-tuning
Easy
187
Causal Multi-Head Self-Attention
PyTorch
torch
attention
masking
transformer
Medium
188
Train a Tiny GPT to Copy
PyTorch
torch
transformer
language-model
training
Hard