Understanding Progressive Collapse: How To Avoid A Cascading Failure

QCon London 2026

Session architecture

Understanding Progressive Collapse: How To Avoid A Cascading Failure

Wednesday Mar 18 / 01:35PM GMT, Churchill (Ground Fl.) at The QEII Centre, London

Abstract

Small things going wrong can quickly snowball. The cascading failure is often a nightmare scenario for any system. An initial problem, which in isolation seems like such a minor problem, can kick off a chain reaction of ever-increasing failures, potentially leading to catastrophic results.

When a failure of a single component results in the failure of other connected elements, this is known as a progressive collapse. In this talk, Sam Newman looks at this phenomenon in more detail, and he'll examine how it has manifested in major disasters. Based on lessons learned from other industries, Sam will share three key techniques that can be used to mitigate against the progressive collapse occurring in your own system.

This talk will help you understand how to architect your systems in such a way that small failures stay small.

Interview

My session explores what happens when a small initial problem causes a giant catastrophe. In the context of buildings, this is called Progress Collapse. In my talk, I look at what happens when a building suffers a progressive collapse, how these can be mitigated, and what parallels we can draw deal with the cascading failures we see in distributed systems.

My session is about how disparate parts of a system interact, especially in the context of increasingly distributed systems. How we write code may have changed a lot over the last couple of years, but the fundamentals of system design, and the challenges of distributed systems still remain.

  1. When something goes wrong, they tend to look for one obvious cause, blame that and move on, without looking at wider systemic issues
  2. Too much focus on stopping things breaking, and not enough time spent on understanding how the system can continue to work when something does break

Stop looking for single causes of failure!

The curated tracks are what helps QCon stand apart. It means you get a lot less clash between tracks, but also it means that each individual track ends up having something for everyone.

Topics

architecture cloud CD Microservices resiliency
76% senior dev or higher
1:11 speaker ratio
60+ practitioners

QCon London 2026 is a three day conference for senior software engineers, architects and team leads. An international program committee of working engineers selects every session. Patterns and practices, not products and pitches.

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Wednesday 18 March

10:35 Whittle (3rd Fl.) Session resilience How to Find Resilience Bugs in Systems that Don't Exist Hillel Wayne Author of "Logic for Programmers" and "Learn TLA+" 11:45 Whittle (3rd Fl.) Session decentralized Spritely: Infrastructure for the Future of the Internet Christine Lemmer-Webber, David Thompson 13:35 Churchill (Ground Fl.) Session architecture Understanding Progressive Collapse: How To Avoid A Cascading Failure Sam Newman Microservice, Cloud, CI/CD Expert, Author of "Building Microservices" and "Monolith to Microservices", 20+ Years Experience as a Developer 14:45 Churchill (Ground Fl.) Session Keeping the Nation On-Air: How We Think About Resilience at the BBC Tom Everest Head of Department for Architecture and Supply Chain @BBC 15:55 Churchill (Ground Fl.) Session Shielding the Core: Architecting Resilience with Multi-Layer Defenses Anderson Parra Staff Software Engineer @SeatGeek