ML coding interviews don't test whether you've memorized LeetCode templates — they test whether you can hand-write building blocks in NumPy (linear layers, residual connections, layer norm, causal self-attention) and read someone else's training/inference loop well enough to find the bug. Today covers four concepts: the real test in ML coding interviews is hand-implementation, not memorized answers; BPE tokenizer's core logic is 'count frequencies, merge iteratively, encode using the exact same merge order learned during training' — get the order wrong and encode no longer matches decode; batch inference trade-offs throughput against latency and has to handle padding waste across variable-length sequences; and the test for whether to vectorize a loop in NumPy is whether it has cross-element dependencies. The practice problem is a real technical-screen question from Glean — implementing a BPE tokenizer end to end, from training to encode/decode.
2026 ML coding rounds no longer just test 'can you build it from scratch' — they also test whether you can read code someone else broke. Today covers five topics: a state-machine design for LLM inference scheduling, strategies for debugging existing ML code, NumPy shape traps, leakage prevention in pandas time-series features, and computing AUC-ROC by hand. The practice problem is adapted from a recently leaked Anthropic OA: a simplified GPU request scheduler.
BytePlus ModelArk Coding Plan offers Lite ($10/month) and Pro ($50/month) subscriptions covering models such as DeepSeek-V4, GLM-5.2, and Seed-2.0 in tools including Claude Code and Cursor. Lite includes about 24,000 requests per month; Pro includes five times as many.
ML coding rounds don't test leetcode recall — they test whether you can implement attention, k-means, and other ML primitives from scratch using only NumPy, while articulating the shape and complexity at every step. Today covers five high-frequency topics: vectorized thinking, softmax numerical stability, shape tracking and complexity analysis, padding/masking for batch inference, and how to verify correctness when hand-coding algorithms.
AI Engineer coding interviews aren't identical to SWE — beyond LeetCode medium, you'll face ML-flavored problems (implementing a tokenizer, writing a batch inference pipeline, handling sparse matrices). Strategy: practice LeetCode medium to 70% pass rate, then spend remaining time on numpy/pandas operations, data processing pipelines, and ML-related programming problems.