At Keplars, performance and reliability are not optional.
They are core to how we build our email infrastructure.
Over the past few months, we've been re-evaluating parts of our stack to ensure we're aligned with long-term scalability, performance, and openness. One of those decisions was around our in-memory data layer.
We've decided to migrate from Redis to Valkey.
This wasn't a reactive decision. It was a deliberate step based on performance, architecture, and long-term ecosystem alignment.
The Context
Redis has been a foundational technology for years.
It's fast, reliable, and deeply integrated into modern systems.
However, recent changes around licensing and governance have shifted how teams evaluate its long-term fit, especially for infrastructure-heavy products.
At the same time, Valkey has emerged as a strong alternative.
What is Valkey?
Valkey is a fully open-source fork of Redis, released under the BSD 3-Clause license and backed by a growing open-source community.
It maintains compatibility with Redis APIs, which makes migration straightforward, while introducing improvements in performance and system efficiency.
Why We're Choosing Valkey
1. Multi-threaded Architecture
One of the biggest limitations of Redis is its single-threaded execution model for command processing.
Valkey introduces multi-threaded I/O and execution capabilities, allowing better utilization of modern multi-core systems.
For a system like Keplars, where throughput and concurrency matter, this directly translates to:
- Higher parallel processing capacity
- Better CPU utilization
- Improved scalability under load
2. Better Memory Efficiency
Memory management plays a critical role in systems handling high-volume, real-time workloads.
Valkey brings improvements in how memory is handled internally, resulting in:
- More efficient memory usage
- Reduced overhead under heavy workloads
- Better predictability in performance
This is especially important for us as we scale email events, delivery states, and real-time tracking data.
3. Open Licensing & Long-Term Flexibility
Redis has transitioned to a more restrictive, commercial-friendly license model.
While it remains usable, the shift introduces considerations around:
- Vendor lock-in
- Contribution model changes
- Long-term ecosystem control
Valkey, on the other hand, is:
- Fully open-source (BSD 3-Clause)
- Community-driven
- Self-host friendly without restrictions
For Keplars, this aligns better with how we think about infrastructure: open, flexible, and not dependent on licensing constraints.
4. Higher Throughput, Lower Latency
Performance benchmarks show that Valkey can achieve:
- Up to ~230% higher throughput
- Lower latency under concurrent workloads
For an email infrastructure platform, this matters directly:
- Faster event processing
- More reliable delivery pipelines
- Better real-time analytics
This allows us to maintain responsiveness even as usage scales.
What This Means for Keplars
This migration is not just a backend change. It directly impacts the experience we provide:
- More consistent performance under load
- Faster processing of email events
- Better scalability as we grow
- Stronger alignment with open infrastructure
Most importantly, it ensures that we are building on a foundation that is both technically robust and future-proof.
Final Thoughts
Redis has played a significant role in shaping modern infrastructure, and it continues to be a strong technology.
But as systems evolve, so do the requirements around performance, scalability, and openness.
Valkey represents a direction that aligns closely with how we want to build Keplars:
- High-performance
- Transparent
- Community-driven
- Built for long-term scale
We're excited about this shift and what it enables going forward.
