What is ETL Developer: Role Description, Responsibilities, and Skills

Businesses and consumers today are generating massive amounts of data. By 2018 the world had generated 33 zettabytes of data and the expectation is that by 2025 175 zettabytes of new data will have been created. The rate at which data is being generated is only increasing exponentially. 

Data engineers and data scientists have the skills to analyze this data to create actionable insights. Unfortunately, this data in its raw format is not usable. To provide engineers with data that can be used, it needs to be worked on. This is where an Extract, Transform, Load engineer, or ETL developer comes into the equation. 

In small and medium-sized organizations, this work can be performed by an engineer from the IT team. However, as the volume of data and work required to format it increases, someone with more specific skills is needed. 

When it comes to Business Intelligence (BI), ETL developers hold a critical position. Their role of extracting data, transforming it into a usable format, and loading it into new systems is what helps make data accessible and useful. Firms need to have someone with these skills available to ensure that the data they have access to is correctly stored and in a format that can be processed easily.

What does an ETL Developer Do?

Within a BI project, there are several critical roles for project success. An ETL developer is one of these roles and they are responsible for the Extract, Transform and Load stages. These developers can be tech leads, project managers, or engineers depending on the project and its requirements. 

• Extract – In any organization, multiple systems are gathering data simultaneously. A CRM system will gather customer and sales information, an ERP system gathers business process data and an Accounting system will compile company finances. The extract step of the process is when all of this information from different sources is collected and put into a temporary storage location.
• Transform – In the transform, stage data is converted into a uniform format so that it can be used. For example, a CRM system might store prices in Canadian dollars instead of US dollars. 
• Load – The load stage is the final step in the process and is where the data is loaded into a database for data processing and analysis.

The ETL developer does not work in isolation – instead, they collaborate with other team members to understand business needs and end-user requirements. ETL developers work on the underlying system architecture and look after tasks associated with data analytics. The developer works to analyze the organizations’ data needs and helps to define a single unified format for the data. The ETL developer will design a target database and create the data flow to move data to that database.

Some of the primary tasks they are responsible for include:

ETL Process Management

Within the ETL process management step, the ETL developers’ responsibilities include outlining the overall ETL process. This includes defining the borders for data processing along with building the overall system architecture for the data pipeline.

ETL developers are also responsible for the documentation of the requirements of the system including the development and implementation of any ETL tools that may be needed. 

Data Modeling

One of the primary ETL developer responsibilities is defining the format of the data required. This step is performed in the data modeling phase where the developer determines what the end format of the data will be. Once these data models are created, documentation is built through a collaboration with data and business analysts. The models are used by the ETL developers to help them better define the transformation phase.

Warehouse Architecture Modeling

A data warehouse is a facility used to store and save structured data. This data often comprises smaller areas known as data marts. ETL developers with database skills define the overall data warehouse structure and also take responsibility for determining the tools that should be used. 

Data Pipeline Creation

This is a critical role and responsibility for the ETL developer. A data pipeline is an infrastructure that is capable of automatically performing several actions:

• Data extraction – an ETL tool can be integrated to automatically extract information from different sources.
• Data upload – data is uploaded to a formatted staging area. While this can be in the warehouse, it is often kept in a separate database to maintain data quality and integrity.
• Data formatting – data uploaded to the staging area is formatted to meet key criteria. This formatting can include data cleansing where useless fields are removed, the addition of metadata, or even data mapping to find connections between data.
• Data loading – here data is loaded either sequentially or in a real-time manner based on the requirements.

ETL Tools Development

Testing (QA, ETL)

The ETL developers’ responsibilities with testing are quite involved. They are in charge of testing the system, data models, warehouse architecture, and units. In addition to the standard QA tests, they also look after data model testing, representation tools, data flow validation, and system performance testing.

What is the Skill Set of an Ideal ETL Developer?

An ETL developer has experience in database management and often has a software engineering background. 

Some of the more specific ETL developer roles and responsibilities include:

Extensive Experience With Pre-Made ETL Tools

There are quite a few tools already on the market that can help with data engineering. Some ETL tools can be used straight from the box which simplifies the process considerably. In this instance, the ETL developer is responsible for the integration of the tool and its overall connectivity between the warehouse and data source.

Strong Data Analysis Skills

As ETL developers are involved in data analysis, they need to have a grounding in data mapping, data formatting, and data modeling.

Solid Database Engineering Background

A solid grounding in database engineering is a key requirement of the ETL developer role. The individual needs to have an understanding of SQL/NoSQL databases as well as skills with data mapping. The ETL developer also needs to understand warehouse architecture and data storage requirements.

Great Knowledge Base of Scripting Languages

Doing everything manually is a fool’s game. The ETL developer needs to have a strong familiarity with some of the more popular programming languages. This familiarity will allow the ETL developer to create scripts to automate how they deal with complex pipelines and large datasets.

Solid Data Modeling Skills

ETL developers need to have the ability to read and analyze data and come up with a transformation plan to get the data into the target database. This process is known as data modeling and is a requirement in defining the tools needed for data transformation.

Putting All Skills Together

An ETL developer needs to have not only a strong technical grounding but also an understanding of the business. They should have organizational and time management skills so they work with people throughout the organization. They also need to have good communication skills. Finally, an ETL developer needs to have a creative streak as they are responsible for designing a solution to make use of data.

When does a Company Need an ETL Developer?

As the ETL developer overlaps with other data engineering positions knowing when to use an ETL developer is critical. For organizations looking to build large-scale data processing systems with complex data flows, the skills of an ETL developer are essential. Consider an ETL developer when your organization is growing quickly and you do not have the in-house IT skills capable of leveraging your data. 

There are some instances where another role might be more suitable based on business requirements. 

BI Developer

BI developers work closely with BI interfaces and data pipes. A BI developer might be a better option if your project is built around ready-made solutions. In this case, BI developers have the skills needed to maintain the system.

Warehouse Developer

If a data warehouse is your key concern and area of focus, a warehouse developer might be a better option. If your warehouse developer has expertise with BI and can use data integration tools they might be an alternative worth considering.

Summary

As companies continue to generate data, obtaining actionable insights becomes ever more critical. Unfortunately, finding a resource with all of the skills needed in the ETL developer role is not easy. The role is not only technically complex it also requires solid business skills. 

Partnering with a company like NIX is the solution here. At NIX we have a team of developers and project managers available to help you make your next project a success. We understand the importance of the ETL developer role and can work with you to help you see the benefits also. Contact us to find out how we can help you.