Rafael Fernández
mathematician · software engineer
I design and build type-safe, composable systems — from distributed data platforms to high-performance processing engines. Scala and functional programming at heart, Rust when performance demands it.
Approach
Engineering with Mathematical Precision
Grounded in formal methods and algebraic thinking, I deliver software that is correct by design, scales under load, and remains maintainable as systems grow.
Expertise
What I build
Distributed Systems & Data Platform Engineering
Designing and operating distributed data platforms at scale — from batch and streaming pipelines on Apache Spark and Databricks to cloud-native microservices on AWS EKS.
End-to-end ownership: architecture, implementation, performance tuning, and production operations.
- Distributed execution engines for batch and streaming workloads (Apache Spark, Databricks, Apache Airflow)
- Cloud-native infrastructure on AWS: S3 data lakes, SQS event handling, microservices on EKS
- Secure configuration-driven pipelines with HashiCorp Vault and Kubernetes
Functional Programming & Type-Safe API Design
Building backend systems with Scala and the Typelevel ecosystem — http4s, cats-effect, fs2 — using Tagless Final, typeclass abstractions, and algebraic design patterns.
Correctness is not an afterthought: type-driven development, property-based testing, and formal reasoning are part of how I work.
- Tagless Final and typeclass-based API design for composable, testable backends
- Purely functional effects with cats-effect and fs2 for safe concurrency and streaming
- Property-based testing and TDD for high-confidence, production-grade software
Rust & High-Performance Systems Engineering
Applying Rust for performance-critical components and contributing to open-source projects like Apache DataFusion and Sail.
From PoCs to production: building reliable, low-latency processing stacks with Apache Arrow, DataFusion, and async Rust.
- Apache Arrow and DataFusion for in-memory columnar data processing
- Async Rust with Tokio, Axum, and SQLx for high-throughput backend services
- Open-source contributions to Apache DataFusion and Sail (multimodal compute engine)
Testimonials
Customer Testimonials
His ability to develop complex code with a clear focus on functional architecture and mathematical principles is impressive. Not only does he deliver high-quality solutions, but he also brings deep knowledge in functional programming and algorithm optimization, always aligned with an agile methodology that allows for continuous product evolution.
Handling large-scale data with a functional approach is no small feat, yet his expertise in advanced mathematics and its application in Scala and Apache Spark makes it look effortless. His work has revolutionized our data processing capabilities, all while maintaining agile workflows that foster rapid evolution without sacrificing quality.
Not only does he have a deep understanding of infrastructure, but his methodological approach is based on solid functional programming principles, enabling him to create efficient and scalable solutions. His ability to develop complex solutions and adapt them quickly within an agile framework has significantly improved the stability and speed of our deployments.
Designing high-performance cloud solutions requires a unique combination of skills, and he excels at blending advanced knowledge of cloud architecture with functional and mathematical principles. His agile methodology ensures that our systems remain efficient and future-proof as they evolve with our needs.