Implement an LSTM cell from scratch: the four gates, the cell state, and why it beats a vanilla RNN.
A build-it-yourself check on gated recurrence. What matters is wiring the forget/input/output gates and candidate correctly, keeping cell state distinct from hidden state, and explaining why the additive cell path cures vanishing gradients. The code follows.
Updated Sep 2026 · Grounded in real GenAI, LLM, and AI/ML engineering interview loops and written to a senior-engineer editorial bar.
A build-it-yourself check on gated recurrence. What matters is wiring the forget/input/output gates and candidate correctly, keeping cell state distinct from hidden state, and explaining why the additive cell path cures vanishing gradients. The code follows.
Lead with where the obvious approach breaks, because that is the judgment they are screening for — most candidates jump straight to the happy path and lose the room.
Then walk the failure back through the pipeline in order, naming the one metric the customer's exec sponsor actually cares about before you propose the fix.
