High-level machine learning libraries like PyTorch and TensorFlow make training intelligent agents straightforward, but relying on modern frameworks often hides the complex mechanics working under the hood.

We just posted a video course on the freeCodeCamp.org YouTube channel that demonstrates how to build an entire reinforcement learning framework from scratch in standard C without relying on external libraries or third-party engines.

Here is what the course covers:

  • Implement custom automatic differentiation alongside dynamic computational graphs, memory allocation systems, and matrix data structures to handle forward and backward gradient passes.

  • Code fundamental linear algebra operations from the ground up, including transposed matrix multiplications, ReLU activations, and numerically stable Softmax routines.

  • Develop a fully functional Snake game simulation in C, complete with custom state vector encoding, grid navigation, collision detection, and reward assignment mechanics.

  • Build an end-to-end policy gradient pipeline utilizing trajectory rollouts, replay buffers, advantage estimation, and parameter updates to train the agent autonomously.

Writing reinforcement learning algorithms in C strips away high-level abstractions, forcing a precise understanding of memory layout, computational complexity, and the mathematical foundations of backpropagation. By seeing how every node in a computational graph is allocated and traversed, you gain a deeper, intuitive grasp of how modern neural network architectures execute beneath their high-level wrappers.

This course provides a practical, step-by-step guide in building AI systems from first principles. Watch the full course on the freeCodeCamp.org YouTube channel (2-hour watch).