Migrating from AWS S3 to MinIO

The journey began with a simple but pressing challenge: rising costs. Over time, as the company’s data volume grew exponentially, the expenses associated with AWS S3 became increasingly difficult to justify. While S3 provided a robust and reliable service, the storage bills were steadily climbing and began to overshadow other operational costs. For the engineering team, it was clear that maintaining long-term sustainability required a more cost-efficient solution—without sacrificing performance or reliability.

Beyond financial considerations, there were also technical motivations. The team needed greater control over storage management, flexibility in deployment, and the ability to fine-tune scaling strategies according to business needs. AWS S3, though feature-rich, often imposed limitations tied to its ecosystem and pricing model. This set the stage for exploring alternatives that could offer both efficiency and autonomy.

The Migration Challenges

The migration process was far from straightforward. The first obstacle was API compatibility. Although MinIO is S3-compatible, subtle differences in implementation meant that not every integration worked seamlessly out of the box. Applications that had been tightly coupled with AWS services needed to be carefully refactored to ensure smooth communication with MinIO.

Another challenge lay in monitoring and observability. With AWS S3, much of the monitoring was handled natively within the AWS ecosystem. Transitioning to MinIO required setting up new monitoring stacks, fine-tuning metrics, and ensuring that performance, latency, and error rates were fully visible in real time.

Scaling also introduced complexity. Unlike AWS, which abstracts much of the infrastructure, deploying MinIO on-premise and in hybrid environments meant that the team had to take ownership of infrastructure orchestration and scaling policies. Balancing storage distribution, ensuring high availability, and maintaining data durability required careful planning and robust testing.

Why MinIO?

Despite the challenges, the team chose MinIO for several key reasons.

• Open-source flexibility: MinIO’s transparent development model and active community provided confidence in long-term viability.
• S3-compatibility: This allowed existing tools and workflows to be adapted rather than rewritten from scratch.
• Deployment freedom: MinIO could be deployed on-premise, in private clouds, or even alongside existing cloud environments, offering true flexibility.
• Significant cost savings: By eliminating vendor lock-in and high recurring fees, MinIO delivered immediate and measurable financial benefits.

Development Obstacle

One of the most demanding aspects of the migration was dealing with 40 backend API endpoints tightly coupled with AWS S3. Over time, the codebase had accumulated a large amount of duplication—each endpoint contained its own S3 upload and retrieval logic.

To make the migration sustainable and minimize future technical debt, the team decided to refactor the duplicated code into a centralized service layer. By consolidating all storage operations into a single service file, both upload and retrieval could be managed consistently through one entry point.

This not only simplified the transition to MinIO but also improved long-term maintainability. Any future changes to storage logic—whether related to authentication, error handling, or performance optimizations—could now be applied in one place without modifying dozens of endpoints.

The Outcome

The migration ultimately proved to be a success. Storage costs were reduced significantly, freeing up budget for other critical initiatives. Performance remained stable and reliable, even under high workloads, thanks to the team’s careful planning and optimization. Most importantly, the company gained flexibility—the ability to manage, scale, and deploy storage infrastructure on its own terms, without being bound by the constraints of a single cloud provider.

The project closed with a renewed sense of confidence: the company had not only solved a cost problem but also laid the foundation for a more resilient, scalable, and future-proof storage strategy.