Cracking ML Interviews

Open in the interactive study hub

Choose Your Track

This repository has over 100 guides. You do not need all of them: you need one track, in order.

Pick a track below, follow its stages top to bottom, and skip everything else until you finish. Coming back for a second track later is much easier than trying to learn two at once.


Table of Contents

  1. The 30-Second Chooser
  2. Pick by Where You're Coming From
  3. The Common Core
  4. Track 1: Machine Learning Engineer
  5. Track 2: AI / GenAI Engineer
  6. Track 3: Data Scientist
  7. Track 4: Data Engineer
  8. Track 5: MLOps / Platform Engineer
  9. Track 6: Deep Learning Engineer
  10. Track Comparison
  11. How to Actually Study This
  12. Frequently Asked
  13. Related Topics

The 30-Second Chooser

Find the row that sounds most like you.

If you want to... Your track
Train models and ship them into a product ML Engineer
Build apps on top of LLMs: chatbots, RAG, agents AI / GenAI Engineer
Answer business questions with data and experiments Data Scientist
Build the pipelines and warehouses everything else runs on Data Engineer
Run the infrastructure that serves and monitors models MLOps / Platform Engineer
Work on model architectures, training, and fine-tuning Deep Learning Engineer

Still unsure? Two honest tie-breakers:

You can also just start with the Common Core below: the first two weeks are identical for every track, so you can defer the decision.


Pick by Where You're Coming From

Your background Recommended start Why
Software engineer AI / GenAI or MLOps Your existing skills transfer almost entirely; you're adding a layer, not starting over
Data analyst Data Scientist You already have SQL and statistics: the closest jump
Student / new grad ML Engineer You have time for the foundation, and it opens the most doors later
Backend / DevOps engineer MLOps Containers, CI/CD, and monitoring are already yours; add the ML-specific parts
Researcher / academic Deep Learning You have the maths; you're adding engineering and production practice
Career switcher, non-technical Common Core, then AI / GenAI Learn Python properly first; GenAI gives visible results soonest
Already an MLE, want to move into AI AI / GenAI, skipping its foundation stage Your fundamentals hold; you need LLM-specific depth

The Common Core

Every track needs these. If you are early, do this first and decide afterwards: roughly 1-2 weeks.

  1. Python for AI Engineering: async, typing, Pydantic, APIs, logging
  2. Statistics & Probability: distributions, hypothesis testing, the CLT
  3. Model Evaluation and Metrics: the single most reusable guide in this repo
  4. Python Coding Challenges and SQL Coding Challenges
  5. GitHub Project Setup, so your work is shareable from day one

Everything after this is track-specific.


Track 1: Machine Learning Engineer

Job titles: Machine Learning Engineer, Applied Scientist, ML Software Engineer Prerequisites: comfortable Python; basic linear algebra and probability helps but can be learned alongside Realistic time to interview-ready: 3-4 months from the Common Core, part-time

Stage 1: Foundations (3-4 weeks)

Stage 2: Deep learning (3-4 weeks)

Stage 3: Production (3-4 weeks)

Stage 4: Interview prep (2-3 weeks)

Build this: a tabular prediction model served behind a FastAPI endpoint, containerized, with tracked experiments and a monitoring dashboard. End to end matters more than accuracy.

You're ready when you can explain bias/variance without notes, choose a metric and defend it against alternatives, spot data leakage in someone else's setup, and describe how you would monitor and roll back a deployed model.


Track 2: AI / GenAI Engineer

Job titles: AI Engineer, GenAI Engineer, LLM Engineer, Applied AI Engineer Prerequisites: solid Python and API work. You do not need to know how to train a model. Realistic time to interview-ready: 2-3 months, part-time: the shortest path here

Stage 1: LLM foundations (2-3 weeks)

Stage 2: Retrieval (2-3 weeks)

Stage 3: Agents (2-3 weeks)

Stage 4: Production (2-3 weeks)

Stage 5: Interview prep (2 weeks)

Build this: a RAG assistant over a real document set with citations, hybrid search, a reranker, an evaluation harness, and a cost-per-request number you can quote. The eval harness is what separates candidates.

You're ready when you can diagnose whether a bad RAG answer came from retrieval or generation, design an eval suite for a non-deterministic feature, explain prompt injection and how tool permissions bound it, and state your system's cost per request and the three biggest levers on it.

The deeper curriculum for this track is The Agentic AI Engineer Roadmap: 34 topics from foundation to frontier. Use it after Stage 3.


Track 3: Data Scientist

Job titles: Data Scientist, Product Data Scientist, Quantitative Analyst Prerequisites: SQL, and genuine comfort with statistics Realistic time to interview-ready: 2-3 months, part-time

Stage 1: Statistical foundation (3-4 weeks)

Stage 2: Modeling (3 weeks)

Stage 3: Experimentation and communication (2-3 weeks)

Stage 4: Interview prep (2 weeks)

Build this: an end-to-end analysis answering a real business question: framing, EDA, a model, an experiment design, and a written recommendation. The write-up is the deliverable, not the notebook.

You're ready when you can design an A/B test including sample size and guardrails, explain a model's output to a non-technical stakeholder in their vocabulary, write window-function SQL fluently, and recognize Simpson's paradox and the peeking problem in a described scenario.


Track 4: Data Engineer

Job titles: Data Engineer, Analytics Engineer, Data Platform Engineer Prerequisites: strong SQL, comfortable Python Realistic time to interview-ready: 2-3 months, part-time

Stage 1: Modeling and architecture (2-3 weeks)

Stage 2: Pipelines (3 weeks)

Stage 3: Modern stack (2-3 weeks)

Stage 4: Serving ML (1-2 weeks)

Stage 5: Interview prep (2 weeks)

Build this: an ingestion → transform → warehouse pipeline orchestrated in Airflow, modeled in dbt, with data quality tests that block on failure and a documented lineage graph.

You're ready when you can design a star schema from requirements, explain idempotency and why partial writes must never be visible, argue batch versus streaming from the latency the business actually needs, and describe how late-arriving data is handled.


Track 5: MLOps / Platform Engineer

Job titles: MLOps Engineer, ML Platform Engineer, ML Infrastructure Engineer Prerequisites: real software engineering experience; Linux and containers Realistic time to interview-ready: 2-3 months if you already do DevOps

Stage 1: ML literacy (2 weeks)

You need enough to reason about models, not to build them.

Stage 2: The MLOps core (3-4 weeks)

Stage 3: Infrastructure (2-3 weeks)

Stage 4: LLM operations (2 weeks)

Stage 5: Interview prep (2 weeks)

Build this: a deployment pipeline that trains, gates on evaluation, registers, deploys to a canary, and rolls back automatically when metrics degrade. The rollback is the interesting part.

You're ready when you can explain training/serving skew and how a feature store prevents it, describe a complete rollback (model and feature pipeline), design promotion gates that catch a slice regression, and estimate GPU cost per thousand predictions.


Track 6: Deep Learning Engineer

Job titles: Deep Learning Engineer, Research Engineer, Applied Scientist Prerequisites: linear algebra, calculus, probability. This track is the most mathematically demanding. Realistic time to interview-ready: 4-5 months, part-time

Stage 1: Fundamentals (4 weeks)

Stage 2: Architectures (4 weeks)

Stage 3: Modern practice (3 weeks)

Stage 4: Interview prep (2 weeks)

Build this: a transformer implemented from scratch, then a fine-tune of an open model on a domain dataset with a proper evaluation and a documented ablation.

You're ready when you can derive attention including why scores are scaled by √d_k, diagnose a NaN loss in order of likelihood, explain what to do when a model won't fit in GPU memory in escalating order, and describe LoRA's mechanism and memory savings.


Track Comparison

ML Engineer AI / GenAI Data Scientist Data Engineer MLOps Deep Learning
Maths required Medium Low High Low Low High
Coding required High High Medium High High High
Time to job-ready 3-4 mo 2-3 mo 2-3 mo 2-3 mo 2-3 mo 4-5 mo
Fastest for a SWE - Yes - - Yes -
Guides in the track ~20 ~22 ~13 ~16 ~18 ~14
Core interview round System design Evaluation Statistics & experiments Data modeling Reliability & rollback Architecture depth
Least likely to go stale High Medium High High Medium High

How to Actually Study This

Follow the stages in order. They are ordered by dependency, not by interest. Skipping ahead to agents before understanding evaluation is the most common way people stall.

Build after every stage. Reading a guide creates recognition, not recall. A small project after each stage converts one into the other, and it gives you the material for the project deep-dive round, which decides more interviews than the technical rounds do.

Answer out loud. Every guide ends with an Interview Q&A section. Read the question, answer it aloud before reading on, and notice the gap. Silent reading consistently overestimates how well you know something.

One track at a time. Two half-finished tracks interview worse than one finished one.

Depth beats breadth in interviews. One project you can discuss five layers deep beats five tutorials. Interviewers probe until they find your limit; the goal is for that limit to be deep, not wide.

When you're within a few weeks of interviewing, switch to the 2026 Interview Roadmap: it has the role-by-role focus matrix and study plans for 1 week, 1 month, and 3 months.


Frequently Asked

Do I need a PhD? No, for every track here except some research positions. PhDs matter for research scientist roles at frontier labs. ML Engineer, AI Engineer, Data Engineer, and MLOps roles are engineering roles that hire on demonstrated ability.

How much maths do I actually need? For AI/GenAI, Data Engineering, and MLOps: very little beyond comfort with probability and reading a formula. For ML Engineer: linear algebra and probability at an undergraduate level. For Data Science: real statistical depth, since it is the interview. For Deep Learning: solid linear algebra, calculus, and probability.

Can I switch tracks later? Yes, and it gets easier each time: the Common Core is shared, and adjacent tracks overlap heavily. ML Engineer ↔ Deep Learning and AI Engineer ↔ MLOps are the easiest moves.

Do I have to read every guide in my track? No. The stages are the path; the rest of the directory is reference. Use the "Guides in This Track" index in each directory's README when you need something specific.

How long does this really take? The estimates assume 10-15 hours a week and existing programming ability. Full-time roughly halves them. Starting from no programming background, add 2-3 months for Python first.

Is the AI/GenAI track a shortcut? It is faster to a first job, and that is real. It is also a shallower foundation: if the tooling shifts, ML Engineer fundamentals transfer and prompt-level knowledge does not. Many people start with AI/GenAI for the job and backfill fundamentals afterwards, which is a perfectly reasonable order.

I already work in ML. Where do I start? Skip to the stage covering what you don't do daily. Most working MLEs have gaps in evaluation, monitoring, and system design rather than in modeling.


View or edit this guide on GitHub