Why a Phased Launch Beats the Big Bang for Mission-Critical Deployments 

Project managers Henrik Rouet-Leduc and Andreas Hultqvist share lessons learned from deploying high-stakes systems without disrupting daily operations. 

When it comes to launching mission-critical systems, even small glitches can have big consequences. A phased rollout not only reduces the risk of disruptions but also allows for thorough testing in real-world conditions, enabling teams to fine-tune performance and address feedback early. 

Phased Launch in Action: B3’s Cloud-Native CSD 

In December 2024, Brazilian marketplace operator B3 took the first step in rolling out its new, elastically scalable, cloud-native CSD system. Instead of opting for a full-scale, all-at-once go-live, B3 chose a gradual launch approach, prioritizing stability and a seamless transition for all users. 

Henrik Rouet-Leduc, Project Manager from Vermiculus, explains why this approach was to prefer: 
“Taking a phased approach is the safest way to launch a mission-critical system without disrupting day-to-day operations. It gives us full control over each step and allows for a gradual, stable transition. Launching in phases also offers the market or marketplace operator new functionality as early as possible, rather than waiting to unlock all the benefits at the end.” 

He continues: 
“Together with B3, we’ve designed a smart rollout strategy that not only ensures a smooth replacement of the current CSD but also delivers tangible market value from day one. Early user feedback also helps us adapt and fine-tune our microservices as we go.” 

This approach improves overall system safety, enhances the user experience, and builds confidence among stakeholders as new features are introduced gradually and with control. 

Continuous Delivery: The MIAX Futures Case 

Andreas Hultqvist, Project Manager at Vermiculus, shares similar experience from working with MIAX Futures on their new microservice-based risk system. 

Since late 2024, Vermiculus has been gradually delivering a comprehensive new risk management system to MIAX Futures. The project has followed a truly agile approach, with new functionality released to production every two months. Key features delivered so far include collateral management with real-time collateral valuation, real-time risk monitoring, various stress tests, and portfolio and contract backtesting. 

“In the beginning, data from MIAX Futures’ legacy system serves as the primary data source and is used as a reference. After a transition period, the new system will take over as the golden source and the legacy system will be gradually phased out,” says Andreas Hultqvist. 

He adds:
"By working with continuous small deliveries, we enhance system reliability by ensuring that each update is carefully validated in a controlled, real-world environment. This approach makes the system progressively more reliable and secure with each release." 

Phased launches offer a practical way to manage risk, gather early user feedback, and ensure system stability during complex deployments. As Andreas Hultquist puts it: 

"A phased rollout lets us offer the market new functionality and added value in real-time as fast as possible, in a controlled way, while keeping the system running smoothly. Going into production with a mission-critical system is always a critical and complex process. While our team brings experience from over 80 go-lives with exchanges, clearing houses, and CSDs worldwide, for our customers this is often a rare and challenging undertaking," says Andreas Hultqvist and continues:

"Taking a phased approach allows us, together with our customer, to gather experience from the process and specific production environment. This approach not only helps reduce risk but also gives our customers the opportunity to gradually build confidence and familiarity with the system, ensuring a smoother, more informed rollout of upcoming releases."