Data Engineering
January 19, 2024
min read

Exploring the Dynamics of Data Integration: ELT and ETL in the Modern Data Processing Landscape

January 19, 2024

Data is the lifeblood of modern businesses, but there are several issues when it comes to truly harnessing the value of data. Every year, due to poor data quality, organizations can lose up to $12.9 million on average, and the complexity of data ecosystems only leads to poor decision-making.

To improve data quality and integration, there are two options to choose from: ELT vs ETL. Both wield formidable tools to transform raw data into actionable insights, but their strategies diverge sharply. ETL focuses on a meticulous process to screen data before loading it into the data warehouse. Meanwhile, ELT boldly throws it all in and then sculpts it to perfection. 

So, which approach reigns supreme? This blog dissects the intricate ETL vs ELT differences, unveiling their strengths, weaknesses, and ultimate purpose – helping you choose the champion for your data journey.

Understanding ETL: Unraveling the Traditional Approach

Let us start by understanding the traditional approach, Extract, Transform, and Load (ETL). ETL is a data integration methodology that emerged in the 1970s and is still most prevalent among on-premise databases.

In this process, we first extract raw data from multiple sources, transform the data on a secondary processing server, and then load the refined data into the data warehouse or data lake for further analysis.

ETL Explained: Extract - Transform - Load | Blog

ETL's strength lies in its meticulousness. By transforming data before loading, it ensures data quality and consistency within the warehouse. This makes it ideal for smaller, well-defined datasets with predictable analysis needs. However, as data volume explodes and agility becomes paramount, ETL can falter. Its sequential nature creates bottlenecks, and pre-defining transformations can become a rigid straitjacket in the face of evolving requirements.

Thus, although ETL is ideal for ensuring data quality and control, for larger datasets that are mainstream in the modern world, it can be an impediment.

The Rise of ELT: Flipping the Script on Data Integration

ELT is a more recent methodology that is rewriting the rules of data integration. In ELT, we first integrate raw data and then refine it. This approach works in the following way:

  1. Extraction & Loading: ELT raw data from multiple sources is extracted. This data is loaded into the system without any enhancements or refining.
  2. Transformation in the Post-Load Phase: Once settled, the data undergoes refinement. The powerful processing engines of the data warehouse start working on this data, wielding sophisticated algorithms to sculpt raw data into meaningful insights.
ETL process explained

Since data is seamlessly integrated into the data warehouse during loading and made available to business intelligence tools, the process of integration and analysis is much faster. This makes ELT the ideal platform for large amounts of unstructured data. It is more commonly used in cloud-based infrastructure, where we have to work with large amounts of data with faster processing efficiency.

Comparative Analysis: ELT vs ETL

To help you decipher which option you need to opt for, here is a quick comparison of ELT vs ETL processes head-on.

Performance Metrics

  • ETL Efficiency: When it comes to efficiency, ETL focuses on improving data before usage, making the processes post transformation highly streamlined and quick. However, while this is an excellent approach when dealing with smaller datasets, larger volumes can be an issue. 
  • ELT Parallelism: ELT, on the other hand, focuses on doing the extraction and loading process in parallel. By directly loading raw data into the data warehouse, you can unleash the warehouse's inherent scalability, handling massive datasets with ease and facilitating near real-time analytics.

Flexibility and Agility

  • ETL Adaptability: Since ETL pipelines work individually, adapting to changing data requirements can be complex. Data cleansing and transformation need to be revamped completely, requiring detours and potentially delaying analysis and reporting.
  • ELT Post-Load Transformation: ELT focuses on transformation after loading, allowing for flexible analysis of raw data in diverse formats and adapting readily to evolving requirements.

Scalability Considerations

  • ETL Scaling Challenges: As data volumes increase, ETL infrastructure can have limitations. Dedicated servers and hardware upgrades become necessary, driving up costs and slowing down the scaling process.
  • ELT Scalability Benefits: ELT is the ideal option for scaling and utilizing the cloud’s limitless expanse. It offers you a pay-as-you-go model to let you scale effortlessly, adapting to data growth without any hefty upfront investments.

Data Volume and Latency

  • ETL Data Volume Handling: For smaller datasets, ETL's pre-processed structures shine, enabling lightning-fast queries. However, as data volumes increase, latency can creep in, making real-time insights difficult.
  • ELT Data Streaming: ELT can be the ideal option for real-time data analysis. Data streams directly into the warehouse, allowing for near real-time transformations and analysis — perfect for fast-paced environments where every second counts. 

Maintenance and Monitoring

  • ETL Maintenance Challenges: Maintaining an ETL pipeline can be complex and requires specialized skills and constant vigilance to ensure data quality.
  • ELT Automated Monitoring: ELT has comparatively lower maintenance and monitoring needs, as data quality checks and automated monitoring tools can proactively identify and address issues.

Cost Considerations

  • ETL Infrastructure Costs: With its dedicated infrastructure and software requirements, ETL can have hefty investment and ongoing maintenance costs.
  • ELT Cloud Benefits: ELT, on the other hand, uses the pay-as-you-go model with cloud-based infrastructure, making it a more cost-effective solution.

Key Differences: ELT and ETL in Focus

Here is a look at some of the clear ELT and ETL differences:

Feature ETL ELT
Data Processing Sequence (Sequential: Extract, Transform, Load) Simultaneous: Extract & Load, Transform
Transformation Timing Before loading After loading
Data Source Compatibility Requires pre-defined schema Handles raw data formats
Schema Evolution Less adaptable Highly adaptable

Case Study: How Spotify Is Using ELT For Artiste Royalties

ELT methodology is already being implemented by companies to improve their data management and intelligence processes. Spotify, a music discovery and streaming app, focuses heavily on data-driven insights to recommend songs that are ideal depending on a user profile.

But while the company was doing exceedingly well in its recommendation and discovery features, it was taking a lot of criticism for calculating artist royalties. Recently, it revamped its revenue model to calculate royalties on a ‘per-play’ basis. Instead of selling music content, the app has made a successful model on streaming it, and has struck a chord with its 24 million-strong user base.

By implementing a business model that allows music creators to get a piece of the pie, the app has surely made a mark in the music industry.

Future Trends in Data Integration

Although we have covered how data integration has experienced a shift from ELT vs ETL processes, the future of integrating databases is going to be much more complex. Data now comes in myriad forms, including sources like cloud services, IoT devices, and third-party apps or APIs. To manage these complexities, the future of data integration will focus on:

  • Use of Cloud-native Solutions: These solutions will be used to eliminate operational efficiencies and eliminate the need for expensive, on-site hardware or software.
  • Shift from Batch To Real-time: Given the nature of modern business applications, data integration needs to happen in real-time, as businesses now require insights to make quick and informed decisions. Real-time integration facilitates continuous data flow and is ideal for providing a competitive edge to modern businesses. Technologies like Big Data and platforms like Apache Kafka or Amazon Kinesis will see rising interest, as these allow real-time data streams alongside traditional batch data for hybrid or fully real-time data integration protocols.
  • Use of AI and ML: The speed and efficiency with which data integration needs to happen require the use of ML algorithms that are self-trained and ready to take on analysis for multiple requirements. AI and ML are increasingly being used to automate data quality checks and optimize transformations within ELT pipelines, which will only improve as we move into a highly complex and data-driven world.


Whether it is ELT vs ETL, you cannot go wrong. Choosing the right methodology depends on your specific data needs, priorities, and infrastructure. To select the option that is apt for your needs, you need to:

  • Analyze your data volume
  • Processing requirements
  • Desired agility to make an informed decision

Whether you choose the meticulous pre-processing of ETL or embrace the agility of ELT, remember that the journey toward data-driven insights doesn't end with selecting a methodology. It's crucial to equip yourself with the right tools and platforms to streamline your data pipelines and maximize the value of your data.

MarkovML stands as a trusted ally in this quest for data excellence. Built on a foundation of data-centric AI, MarkovML empowers teams to collaborate seamlessly, automate workflows, and gain deeper insights into their data—no matter which integration approach you choose.

Ready to conquer the challenges of data integration and unlock the transformative power of your data? Embrace the champion that aligns with your needs, and let MarkovML guide you toward a future of intelligent, actionable insights.


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