Table of Contents
When she’s not designing globally distributed infrastructure, Susan Duker is a volunteer EMT. The skills she uses in emergencies: 1) quick assessment, 2) precise responses, and 3) constant situational awareness, shape how she builds technical systems. In both roles, failure isn’t just inconvenient; it’s the ultimate test of what you’ve created.
She started in telecom when VoIP was new, a time when fake ringtones and call delays ruined user experiences. Susan learned to pinpoint latency, unravel routing issues, and design systems that self-corrected without guesswork or quick fixes—just clean, thoughtful engineering that held up under pressure.
Now, as CTO of XConnect, she applies that approach to global messaging and identity services. Her team builds infrastructure to handle number verification, routing intelligence, and now, following the acquisition of Sekura.id, it’ll have to handle real-time APIs. Susan knows any single point of failure or slowdown ripples outward, disrupting entire systems. She designs with that chain in mind.
In this edition, Susan, CTO, EMT, and mom of four talks about building resilient systems.
About The Series
This is the twenty-fourth installment in the “One Expert, One Topic” series, where field experts select a topic and share essential insights using Matt Abrahams’ What/So-What/Now-What format. Presented in written form, it allows you more time to absorb the topic and guides you on where to go for further learning. We are grateful to our contributors for sharing their wisdom in this format.
What
Susan designs infrastructure built specifically to handle real-time communications. XConnect’s architecture spans multiple global points of presence (PoPs), each built with horizontal scaling and fault tolerance in mind.
But this isn’t just about uptime. Every system is designed to detect failure, reroute traffic, and recover instantly—all while meeting the low-latency demands of time-sensitive services like routing, validation, authentication, fraud prevention, KYC checks, and login verification.
As more platforms move away from SMS-based OTPs and toward silent authentication, the backend infrastructure becomes critical. With the acquisition of Sekura.id and its real time API connections to Operators, Susan’s work integrating the two companies’ systems together will ensure those services can scale, perform, and withstand pressure—without breaking trust.
So What
Messaging might feel asynchronous to the end user, but expectations are anything but. When a user taps “Log In,” banks and apps have hard rules—often requiring that an authentication response completes in under 60 seconds. And now that networks are shifting to silent auth, the margin for error is even smaller.
Silent authentication quietly matches the phone number the user provides with the phone number associated with the SIM in the device, through silent cryptography of the SIM. It reduces friction for users, but only if the infrastructure underneath holds up every time.
Susan has seen what happens when systems aren’t designed for failure. Her team not only focuses on peak performance, they also build for the moment something breaks. Because when you’re handling real-time queries at global scale, recovery is part of the design
Now What
If your platform is betting on silent authentication, real-time fraud checks, or number intelligence, your infrastructure can’t afford to break.
Susan understands that every link in the chain matters—and that speed without stability is just a countdown to failure. Systems are built to perform under pressure, fail gracefully, and recover fast, no matter where the traffic comes from.
You can reach Susan on LinkedIn, or read more from XConnect on network APIs, authentication, and infrastructure design.
In telecom, tech, or emergencies, your performance depends entirely on how you handle the moment something breaks.
