How we interview · Machine learning engineer
Hire machine learning engineers who ship models to production
ML and AI engineers, mid-level to staff, interviewed on turning a business problem into a measurable model and running it in production, including LLM features.
Most ML hiring tests the wrong thing. A candidate who can explain gradient descent may never have shipped a model that real users depend on, and a notebook that scores well is a long way from a feature in production.
We look for engineers who start from the business question, pick the simplest approach that works, measure it honestly, and build the pipeline, serving and monitoring around it. That now includes LLM features: retrieval, evaluation and cost.
What they work on: Python, PyTorch, scikit-learn, feature stores, model serving, vector databases, LLM APIs and evaluation tooling.
When to hire one
- You have data and a clear use case, but no one to take a model to production.
- Your LLM feature works in a demo but is slow, costly or unreliable.
- Your data scientists' models never leave the notebook.
What we assess in machine learning engineers
Every report also covers impact, judgement, how they raise the team and how they work with others.
Craft
- ML fluency
- A broad toolkit, current with the field, and the judgement to choose the simplest method that works.
- Problem framing
- Turning a business goal into a target, a metric and a baseline worth beating.
- Evaluation
- Honest offline and online measurement: leakage, bias, statistical rigour.
- Production ML
- Pipelines, serving, monitoring for drift, latency and cost.
- Software engineering
- Code others can maintain, tests, and reusable components.
How we recommend a level
- Mid-level
- Builds and evaluates models for a defined problem and gets them into production with guidance.
- Senior
- Frames business goals as ML problems, picks metrics that last and owns the model in production.
- Staff / lead
- Builds shared ML tooling and sets how teams train, evaluate and deploy models.
The 60-minute interview
- Warm-up (10 min)
- A model they shipped: the goal, the metric, and what happened after launch.
- Framing (20 min)
- A business problem, such as churn or search ranking, turned into an ML plan with metrics.
- Hands-on (25 min)
- Critique and improve an evaluation, or design a retrieval-augmented feature with its failure cases.
- Their questions (5 min)
- Do they ask about data quality and how success is measured?
Red flags we screen for
- Reaches for a large model before trying a baseline.
- Reports accuracy without asking how it's measured.
- Has never monitored a model after launch.
What you receive for each shortlisted candidate:
Candidate N.S.
Machine Learning Engineer · 60-minute technical interview
- Tested
- Framing a churn prediction problem, and designing evaluation for a support-ticket RAG assistant.
- Strong
- Started with a simple baseline. Spotted label leakage in the sample data. Thought about cost per query.
- Gaps
- Limited experience serving models at scale. Light on online A/B testing.
- Level
- Mid-level, close to senior on problem framing.
- Probe next
- How they would roll out the assistant safely, and monitor answer quality after launch.
Questions about hiring machine learning engineers
Other engineering roles we hire
- Software engineers
- Site reliability engineers
- Data engineers
- Security engineers
- Technical program managers
- Engineering managers
Hiring on your own terms? Permanent hiring, contract hires or interviews only.
Tell us the role.
Four details and we'll come back within a working day with how we'd approach it.
No retainer. You pay only when someone joins. Or write to talent@algosmiths.com