Adam, AdamW and decoupled weight decayML designWrite Adam's update: the first and second moment estimates, bias correction and the step. Why is adding an L2 penalty to the loss not the same as weight decay once Adam's…
Last asked Sep 2026
Mistral AI
A recruiter or hiring manager call, a technical screen (ML fundamentals for research roles), coding and system design (on CodeSignal in a 2026 report), then a final panel with teammates and leadership; pragmatic, and fluent LLM knowledge is expected.
- Keep GPUs fed: fix a training job that waits on its dataML designA training job's GPUs sit idle a third of the time waiting for the next batch. How do you prove the input pipeline is the bottleneck, and then fix it? Cover profiling, parallel…Last asked Sep 2026
- Mixture of experts and expert parallelismML designExplain how a mixture-of-experts transformer layer works and follow a batch of tokens through it: the router, top-k selection, the all-to-all exchange that sends tokens to experts…Last asked Sep 2026
- Reward-model RLHF versus direct preference optimizationML designWalk through a classic RLHF pipeline: supervised fine-tuning, a reward model trained on preference pairs, then policy optimization (PPO) with a KL penalty to the reference model…Last asked Sep 2026
- RMSNorm versus LayerNorm in a transformer blockML designWrite the formulas for LayerNorm and RMSNorm and say what each normalizes. What does RMSNorm give up by skipping the mean, why does it work about as well in practice, and why do…Last asked Sep 2026
- Tensor parallelism versus pipeline parallelismML designA transformer is too big for one accelerator. Explain how tensor parallelism and pipeline parallelism each split it: what is cut, what crosses the wire and when, where the idle…Last asked Sep 2026
- The forward and reverse processes of a diffusion modelML designExplain how a diffusion model is trained and how it generates. Describe the forward process that adds noise step by step, the reverse process the network learns, the usual…Last asked Sep 2026
- Build a RAG agent on the Mistral API, then defend its designAI systemWrite a small Python tool that answers questions over a local folder of Markdown and PDF files with retrieval-augmented generation: ingest and chunk the files, embed and index the…Last asked Jul 2026
- Greedy, top-k and top-p decoding for a language modelCodingYou get a toy language model with a small vocabulary whose forward pass returns next-token logits for the tokens so far. Using NumPy, write the generation loop and three ways to…Last asked Jul 2026
- Nearest-center assignment without an N x K x D distance tensorCodingGiven N points and K centers in D dimensions, assign each point to its nearest center, as in the assignment step of k-means. The obvious broadcast builds an N x K x D array of…Last asked Jul 2026
- Rapid-fire questions on LLM internalsML designA fast round of short questions on how LLMs work: transformer and attention internals, training and fine-tuning choices, and how models are run in practice. Each answer should be…Last asked Jul 2026
- Design a PDF-to-Markdown inference API (sync and async)AI systemBuild a service that turns PDF files into Markdown out of three existing functions: one that splits a PDF into page images (CPU-heavy), an OCR model that reads a page image or a…Last asked Apr 2026
- GPU clusters: capacity left per day and the best K-switch planCodingYou run a few GPU clusters with fixed daily capacities, for example 10, 20. Each day a list of usage records takes GPUs from clusters (a record names the day, the cluster and how…Last asked Apr 2026
- How you use an AI coding assistant in a live coding roundBehavioralThe coding round allows an AI assistant. Before you start, the interviewer asks how you will use it. Explain what you hand to the assistant (boilerplate, lookups, tests) and what…Possibly retired
- Design a multi-tenant fine-tuning and LoRA serving platformAI systemA model provider lets customers fine-tune its open-weight models on their own data through an API, then call the fine-tuned models through the same chat endpoint. Most use LoRA…
- Design an LLM inference serving platformAI systemDesign the system that serves several large models to many customers with low latency and high GPU utilization.