Custom Neural Network Suite & From-Scratch I-JEPA
PROBLEM
Wanted a from-scratch understanding of how modern architectures are actually built, hand-deriving the backpropagation rather than leaning on framework abstractions, and to push that toolkit all the way to a working self-supervised model.
APPROACH
Built a modular neural network suite in low-level Python and CuPy, feed-forward, convolutional, activation, pooling, transformer and embedding layers as reusable, gradient-checked blocks, then used them to implement I-JEPA: a teacher/student/predictor pipeline with an EMA target and masked-patch latent prediction.
OUTCOME
The suite now trains a full I-JEPA end to end. Scaled from 8×8 digits up to 28×28 MNIST, the learned patch tokens reach ~0.95 linear-probe (concat) and 0.85 kNN accuracy by epoch 500, explored interactively below through their attention maps, nearest neighbours and t-SNE.