JobDescription.org

Artificial Intelligence

ML Data Engineer

Last updated

ML Data Engineers design, build, and maintain the data pipelines, feature stores, and infrastructure that make machine learning models trainable, deployable, and trustworthy in production. Sitting at the intersection of data engineering and ML systems, they work closely with data scientists and ML engineers to ensure that the right data — clean, versioned, and at the right scale — reaches training and inference systems reliably. Their work is less about building models and more about making sure models can be built and run without breaking.

Role at a glance

Typical education
Bachelor's degree in computer science, software engineering, or a quantitative field
Typical experience
3–5 years
Key certifications
AWS Certified Data Engineer, Google Professional Data Engineer, Databricks Certified Associate Developer for Apache Spark, dbt Certified Developer
Top employer types
AI-native startups, big tech (FAANG and equivalents), large enterprises with production ML deployments, cloud platform providers
Growth outlook
Data engineering roles projected to grow roughly twice the rate of the broader tech workforce through the early 2030s; ML-adjacent specialization commands 15–25% salary premium
AI impact (through 2030)
Strong tailwind — as enterprises scale from ML experimentation to production deployment, demand for engineers who build reliable data infrastructure for AI systems is growing faster than supply; AI code-generation tools raise productivity expectations but do not displace the core judgment work around training-serving consistency, feature store design, and data quality at scale.

Duties and responsibilities

  • Design and build scalable ETL and ELT pipelines that ingest, transform, and deliver data for model training and evaluation
  • Develop and maintain feature engineering pipelines that compute, store, and serve ML features at training and inference time
  • Implement data validation and quality checks to catch schema drift, distribution shifts, and upstream data breakage before they affect models
  • Build and manage feature stores using tools like Feast, Tecton, or Hopsworks to enable consistent feature reuse across teams
  • Instrument data pipelines with lineage tracking and metadata management using tools such as Apache Atlas, DataHub, or OpenMetadata
  • Optimize large-scale data processing jobs on distributed compute frameworks including Apache Spark, Ray, and Dask for training dataset generation
  • Collaborate with ML engineers to design data contracts, schema standards, and versioning strategies for training and evaluation datasets
  • Operate and monitor pipeline orchestration systems — Airflow, Prefect, or Dagster — to ensure SLA adherence and fast incident recovery
  • Manage storage and retrieval of training datasets and model artifacts on cloud platforms such as AWS S3, GCS, or Azure Blob with appropriate partitioning strategies
  • Evaluate and onboard new data tooling, benchmark pipeline performance, and present tradeoffs to engineering leadership

Overview

ML Data Engineers are the infrastructure layer between raw data and working machine learning systems. They don't build the models, but they build almost everything that makes models possible at scale: the pipelines that create training datasets, the feature stores that serve inputs to online models in milliseconds, the quality checks that catch data problems before they silently degrade model accuracy, and the monitoring systems that alert teams when production data drifts from what the model was trained on.

In practice, a typical week involves a mix of building new pipelines, fixing broken ones, and collaborating with data scientists on the pipeline implications of their feature engineering choices. A data scientist might prototype a feature in a Jupyter notebook that works perfectly on a sample dataset but implicitly uses future information — a subtle form of label leakage that would cause the model to perform well in offline evaluation and poorly in production. The ML Data Engineer's job is to catch that, redesign the pipeline with point-in-time correctness, and implement it in a way that runs reliably at scale.

At AI-native companies and large enterprises running mature ML platforms, the role has a strong platform engineering flavor. The ML Data Engineer might own a shared feature store that dozens of model teams rely on, which means API design, SLA commitments, and the kind of reliability engineering discipline that comes with systems that other engineers depend on. Breaking the feature store is equivalent to breaking the database — cascading failures are fast and visible.

At earlier-stage companies or teams earlier in their ML maturity, the role is often more exploratory: standing up infrastructure that doesn't exist yet, making opinionated tooling choices, and building convention where there is none. This demands broader judgment about what to build versus buy and strong communication with stakeholders who may not have a clear picture of what ML infrastructure actually requires.

The unifying thread is a specific kind of rigor that distinguishes ML pipelines from analytics pipelines. Correctness in ML data infrastructure doesn't just mean the pipeline ran without errors — it means the data that came out is the right data, with the right temporal boundaries, the right schema, and the right statistical properties to make a model trained on it behave as expected when it meets real users.

Qualifications

Education:

  • Bachelor's degree in computer science, software engineering, or a quantitative field (standard expectation)
  • Master's degree in data engineering, computer science, or ML systems at some large tech employers and research-heavy organizations
  • Bootcamp graduates and self-taught engineers are competitive when they can demonstrate production pipeline ownership

Experience benchmarks:

  • 3–5 years of data engineering experience, with at least 2 years in an ML-adjacent context
  • Track record of owning pipelines end-to-end in production — not just building them, but operating them under SLAs
  • Prior experience with feature engineering for ML or with data science teams counts heavily

Core technical skills:

  • Distributed processing: Apache Spark (PySpark), Ray, Dask — understanding partitioning, shuffle, and performance tuning matters
  • Orchestration: Apache Airflow, Prefect, or Dagster; DAG design, failure handling, backfill strategies
  • SQL: advanced query writing, query optimization, warehouse-specific SQL (BigQuery, Snowflake, Redshift)
  • Python: production-quality code, not just notebook code — testing, packaging, dependency management
  • Streaming data: Apache Kafka or Flink for real-time feature pipelines serving online models
  • Feature stores: Feast, Tecton, Hopsworks, or cloud-native equivalents (Vertex AI Feature Store, SageMaker Feature Store)
  • Data quality: Great Expectations, Soda, or Monte Carlo for automated validation
  • Cloud storage and compute: S3/GCS/ADLS, EMR/Dataproc, columnar formats including Parquet and Delta Lake
  • MLflow or similar for experiment tracking and artifact management

ML systems literacy (important differentiator):

  • Training-serving skew: understanding how it happens and how pipelines can prevent it
  • Point-in-time correctness in feature computation
  • Data versioning and reproducibility for model retraining
  • Online vs. offline feature serving architectures

Certifications (helpful but not gatekeeping):

  • AWS Certified Data Engineer or Google Professional Data Engineer
  • Databricks Certified Associate Developer for Apache Spark
  • dbt Certified Developer

Career outlook

Demand for ML Data Engineers is rising faster than most data specializations, driven by a specific gap that the AI wave has exposed: organizations have invested heavily in data science talent and model development, but many of them lack the infrastructure to deploy those models reliably. The result is a well-documented pattern of models that perform well in notebooks and fail in production — and growing recognition that the fix is engineering-grade data infrastructure, not better algorithms.

The Bureau of Labor Statistics doesn't track ML Data Engineer as a distinct category, but data engineering roles overall are projected to grow at roughly twice the rate of the broader technology workforce through the early 2030s. Within that category, roles that combine data engineering with ML systems experience carry salary premiums of 15–25% over pure data engineering positions at comparable experience levels.

The generative AI buildout has accelerated this trend. Large language model fine-tuning and retrieval-augmented generation (RAG) systems both require sophisticated data pipelines — for training data curation, embedding generation, vector store management, and evaluation dataset construction. These are ML Data Engineer problems, and demand from companies building AI products has exceeded available supply since 2023.

Automation is reshaping the role's content more than its headcount. AI-assisted pipeline code generation (GitHub Copilot, internal LLM tools) handles boilerplate faster than before, which is raising the baseline productivity expectation rather than reducing team size. The harder problems — designing systems that don't produce training-serving skew, debugging silent data quality failures in complex DAG dependencies, building feature stores that serve thousands of model requests per second — are not yet automatable and are where senior ML Data Engineers spend the majority of their time.

Career paths branch in several directions. Some ML Data Engineers move toward ML engineering proper — taking on model deployment, serving infrastructure, and online experimentation systems. Others move toward data platform engineering, owning the shared infrastructure that enables entire organizations. A smaller group moves toward ML infrastructure leadership — staff engineer and principal engineer tracks at companies with mature ML platforms.

The geographic concentration of the highest-paying roles remains in San Francisco, Seattle, and New York, but well-funded AI startups distributed across the country and substantial remote hiring from large tech companies have broadened where competitive compensation is available. For engineers willing to engage with the ML systems depth the role demands, the job market in 2026 is about as favorable as it has ever been.

Sample cover letter

Dear Hiring Manager,

I'm applying for the ML Data Engineer role at [Company]. I've spent the last four years building ML data infrastructure at [Company], where I own the feature platform that serves real-time inputs to eight production models handling fraud detection and personalization at roughly 40,000 requests per minute.

The project I'm most proud of is a point-in-time feature computation system I designed last year to eliminate training-serving skew that had been degrading our fraud model's precision over time. The root cause was subtle — an aggregation window in the online serving path was computing over a different time boundary than the training pipeline used — and it had been invisible because offline evaluation metrics looked fine. I built a validation layer that compares online and offline feature distributions on a 2% shadow traffic sample and alerts when divergence crosses a configurable threshold. Within six weeks of deployment, we caught two more instances of the same class of bug before they reached production.

I've worked with Feast for feature storage, Apache Spark for large-scale training dataset generation, Airflow for orchestration, and GCS and BigQuery as the underlying storage layer. I'm comfortable in Python at a software engineering level — not just notebook code — and I've mentored two junior engineers on production pipeline ownership.

What draws me to [Company] is your published approach to evaluation dataset construction and the scale of the ML infrastructure challenges implied by your product surface area. I'd welcome the chance to talk about how my experience with online feature serving and training-serving consistency could contribute.

[Your Name]

Frequently asked questions

What is the difference between an ML Data Engineer and a traditional Data Engineer?
Traditional data engineers typically build pipelines that move data from source systems into warehouses or BI tools for analysts. ML Data Engineers do all of that, but their pipelines are designed with model training in mind — point-in-time correctness, feature versioning, large-scale batch generation, and low-latency online serving. The ML context adds constraints around data freshness, reproducibility, and the need to prevent training-serving skew that most analytics pipelines don't face.
Do ML Data Engineers need to know how to train machine learning models?
Not deeply, but enough to be dangerous. You need to understand what a model requires from its data — label quality, feature distributions, train/val/test splits, time-based leakage risks — so you can build pipelines that don't silently corrupt the training process. You don't need to tune hyperparameters or architect neural networks, but you should be able to read a data scientist's feature engineering notebook and translate it into production-grade code.
What cloud platforms and tools should an ML Data Engineer know?
Cloud platform depth on at least one of AWS (S3, Glue, SageMaker Feature Store, EMR), GCP (BigQuery, Dataflow, Vertex AI Feature Store), or Azure (Synapse, Azure ML) is expected. On the open-source side: Apache Spark, Airflow or a modern alternative, dbt, and at least one feature store platform. SQL proficiency is non-negotiable regardless of seniority level.
How is AI automation affecting the ML Data Engineer role?
The role is experiencing a strong tailwind, not displacement. As organizations move from ML experimentation to production-scale deployment, demand for engineers who can build reliable, governed data infrastructure for AI systems is growing faster than supply. AI-assisted code generation handles some boilerplate pipeline code, but the hard work — designing for training-serving consistency, managing data quality at scale, debugging silent failures in production — requires human judgment that current tools cannot replicate.
Is a graduate degree necessary to become an ML Data Engineer?
No. The majority of working ML Data Engineers hold bachelor's degrees in computer science, software engineering, or a related field. What hiring managers actually screen for is demonstrated experience with distributed data systems, production pipeline ownership, and ML infrastructure concepts — typically evidenced through 3–5 years of hands-on work, a strong portfolio, or open-source contributions.
See all Artificial Intelligence jobs →