Office Hours with Engineering Managing Director Mae Santos

Summary

Mae Santos, Head of Critical Applications and Data Reliability Engineering at Two Sigma, leads a global team across New York, Houston, London, and Tokyo to support critical applications and data pipelines. While software teams frequently prioritize functional features over operational stability, designing systems with reliability in mind from the beginning allows for progressive enhancements without complete rewrites. System architecture should be guided by concrete goals across four key dimensions: availability, observability, scalability, and supportability. In addition, mapping out interconnections among systems, infrastructure, data, and human processes helps teams manage dependencies effectively. Applying automation across support and delivery workflows further reinforces reliability by minimizing human error and accelerating execution.

Context

Reliability is frequently treated as an afterthought in software development, with application features and functionality taking higher priority during initial builds.

Approach / What changed

Santos advocates designing with reliability principles from the start, defining goals for availability, observability, scalability, and supportability, mapping cross-system dependencies, establishing standards, and automating processes to eliminate human error.

Takeaways

• Reliability principles should be built into initial system designs by setting explicit goals for availability, observability, scalability, and supportability.
• Mapping interconnections across infrastructure, systems, data, people, and processes enables long-term architectural iteration without full rewrites.
• Implementing automation wherever possible increases overall system reliability by reducing human error while accelerating delivery and support cycles.

Related reading

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