Key elements of data engineering
Clearly, both the definition and applications of data engineering are incredibly broad. To better understand the discipline, consider the following key elements of data engineering.
Data extraction/collection
As its name implies, this element involves the creation of systems and processes to extract data of varying formats from multiple sources. This includes everything from structured customer data in relational databases and data warehouses, to semi-structured data such as email and website content stored on a server, and unstructured data including video, audio, and text files stored in a data lake. The variety of data formats and data sources are literally endless.
Data ingestion
Data ingestion involves data source identification as well as data validation, indexing, cataloging, and formatting. Given the robust data pipelines common in modern enterprises, data engineering tools and data processing systems are often used to speed up the ingestion of these large datasets.
Data storage
Data engineers take ingested data and design the necessary storage solutions to house it. These solutions include everything from a cloud data warehouse, to a data lake, or even a NoSQL (not only structured query language) database. In addition, data engineers can also be responsible for data management within these storage solutions depending on organizational staffing and structure.
Data transformation
To make data useful for data scientists as they build machine learning algorithms, as well as for use in business intelligence and data analytics, data engineers convert raw data via data cleaning, enrichment, and integration with other sources.
For this reason, data engineers develop ETL (extract, transform, load) data pipelines and data integration workflows to prepare these large datasets for data analysis and modeling. A variety of data engineering tools are utilized (e.g., Apache Airflow, Hadoop, Talend) depending upon the data engineer's data processing needs and the end-user's (e.g., data analysts, data scientists) requirements.
The final step in data transformation is to load the processed data into systems that enable data scientists, data analysts, and business intelligence professionals to work with it to produce valuable insights.
Data modeling, scaling, and performance
Creating and defining data models is another key element of data engineering. Artificial intelligence (AI) is used (e.g., machine learning models) to optimize everything from data volume and query load management, to overall database performance and scaling infrastructure.
Data quality and governance
Making sure that data is accurate and accessible is another key element of data engineering.
Data engineers create validation rules and processes to ensure that organizational data governance policies are adhered to and data integrity is maintained.
Security and compliance
Data engineers are often responsible for ensuring security measures prescribed by organizational cybersecurity protocols and/or industrial data privacy regulations (e.g., HIPAA) are met and all systems are in compliance.
Types of data engineers
The range of opportunities for data engineers is a broad one. Within those opportunities, data engineers tend to focus their careers in one of three ways which help them focus their data engineering skills in their areas of interest.
Generalists
These data engineers are responsible for supporting virtually the entire Data Science Hierarchy of Needs—from data requirements gathering and data collection, to building data pipelines and managing data transformation, to data management and storage, to modeling, data aggregation/labeling, and even simple machine learning algorithms and analyzing data.
Commonly, generalist data engineers work with smaller teams and are more focused on data-centric tasks, rather than data system architecture. For this reason, professionals in data science looking to move into data engineering often choose to start as generalist data engineers.
Pipeline-centrists
Pipeline-focused data engineers are responsible for building, maintaining, and automating data pipelines within big data systems.
Specifically, they build ways for data to move from one place to another (e.g., data pipeline), focusing on functions in the second and third tiers of The Data Science Hierarchy of Needs (e.g., Move/Store, Explore/Transform). Examples include data extraction, data ingestion, data storage, data anomaly detection, and data cleansing.
These professionals also create ways to automate tasks within the data pipeline to improve efficiency, data availability, and lower operational costs. Tending to work for bigger organizations, these data engineers work with larger teams that focus on more complex data science projects and often work with distributed data systems.
Database-centrists
Within larger organizations with significant data assets, database-centric data engineers focus on the implementation, population, and management of a data analytics tool database(s), data analytics platform(s,) and other modern data analytics tools used to create machine learning algorithms and AI features (e.g., Aggregate/Label, Learn/Optimize levels of The Data Science Hierarchy of Needs).
These data engineers may also work with data pipelines as they take transformed data and load it via ETL data engineering tools into various data analytics systems, automating processes where possible and optimizing database efficiency.
Finally, they may also employ data engineering tools to further enhance data for data scientists (e.g., specialized data sets, automated SQL queries, customized data tools).
Data engineering offers flexibility and options
It's important to note that data engineers can choose to specialize even more deeply than the categories above if so inclined—focusing on becoming an expert in top data engineering tools, building ad-hoc business intelligence solutions, focusing on specific cloud-based data platforms, or even leading teams of data engineers, just to name a few of the possibilities. The options are endless!
Further, it's not uncommon for data engineers to switch from being a generalist data engineer to a pipeline-centric data engineer or database-centric data engineer (or vice versa).
Often, as data engineers gain experience and additional skills in certain areas, they will migrate to positions that make use of valuable new skills in the modern data stack (e.g., machine learning, data lakes management, developing top data engineering tools).