AWS User Group UK Meetup #80

Welcome to our November event. We’re delighted to welcome Eduardo Aparicio Cardenes, Senior Frontend Engineer, Super, and a careers panel including Kimberley Clements, Senior Solutions Architect, Amazon Web Services (AWS) and Mike Mead, Technical Director, Scale Factory
Here’s what they’re bringing:

1.6 million transactions a day, over €300M in deposits a month, all running on shared Amazon S3 and CloudFront. Eduardo and his team moved that live payment frontend onto dedicated, jurisdiction-owned infrastructure with Terraform, and finished with zero production incidents. Tonight Eduardo is giving us the part the architecture diagram leaves out: dual deploys, feature flags and a way back that never needed an emergency release.

Same AWS console, very different job. Inside AWS, at a consulting partner, alongside the public sector: where you do the work shapes the problems you get and where your career goes next. Tonight our panel walks us through what each path looks like day to day, what it gives you and what it costs.

A big thank you to our sponsors Cloudscaler & Rayo for making this event possible.

Programme:

• 18:00: Arrival, registration
• 18:15: Talks start
• 20:00: Networking with food and a drink provided by the generosity of our sponsors.

Session 1: Zero Incidents, €300M+ in Monthly Deposits: Migrating a Multi-Jurisdiction Frontend from Shared to Dedicated AWS with Eduardo Aparicio Cardenes

Our payment frontend handles more than 1.6 million transactions every day and over €300M in deposits every month across multiple jurisdictions.
It originally ran on shared Amazon S3 and CloudFront infrastructure. As the platform grew, that shared model created wider failure boundaries: a change for one jurisdiction could affect another, while ownership, production access and cost attribution became increasingly difficult to isolate.
We needed to move a live payment platform to dedicated, jurisdiction-owned AWS infrastructure without disrupting customers.
Using Terraform, we created a repeatable infrastructure pattern for each jurisdiction, with dedicated S3 and CloudFront delivery, DNS, certificates, permissions, security policies, and separate production boundaries. Infrastructure changes moved from manual console operations into versioned, reviewed pull requests.
But building the target architecture was only half of the migration.
The harder part was moving customers safely.
We deployed every application build to both the legacy and new infrastructure, validated the new path in production before customers depended on it, and used feature flags to migrate jurisdictions independently.
If something went wrong, we could move that jurisdiction back to the legacy path without an emergency release.
We started with the lowest-risk jurisdiction and expanded progressively, using both infrastructure health and payment behaviour to decide when to continue.
The migration completed with zero production incidents.
This talk shares what we learned about the part of cloud migrations architecture diagrams often miss: the transition. How coexistence, validation, observability and rollback allowed us to change the infrastructure underneath a live payment platform without making the migration a customer problem.
Learning Takeaways

• Design the transition architecture - coexistence, validation, observability and rollback - not only the target state.
• Dual-deploy to legacy and new infrastructure so cutover becomes a routing decision, with feature flags to move each jurisdiction forward or back without an emergency release.
• Shrink failure boundaries with jurisdiction-owned Terraform stacks, and gate each rollout stage on both infrastructure health and payment behaviour.

Eduardo Aparicio Cárdenes is a Senior Frontend Engineer at Super with nearly 20 years of experience building web applications. His work combines React, TypeScript and AWS services, including Amazon S3 and CloudFront, to build fast, reliable payment experiences. He shares practical lessons on improving performance and simplifying software delivery.

Session 2: Panel Discussion - Same Cloud, Different Careers with Kimberley Clements, Mike Mead and more to follow.

Whether you are two years into AWS or fifteen, where you do the work - inside a consulting partner, a public sector team, a startup or AWS itself - shapes the problems you get, the pressures you are under and the directions open to you next. Most of us only ever see one of those worlds from the inside.
For the second half of the evening we bring three people who have built their careers on AWS from those vantage points onto the stage together. They will talk about how they got where they are, what the work actually looks like day to day, what their path has given them and what it has cost, and what they would tell someone deciding where to take their AWS career next. Expect some straight answers on the worst mistake each of them has made on AWS, and the service they would not want to live without.
Learning Takeaways

• Compare what AWS work really looks like day to day inside AWS, at a consulting partner and alongside public sector customers.
• Weigh what each path gives you, what it costs and how progression works in each.
• Take away straight advice from people who have made the move on where to take your AWS career next.

Kimberley is a Senior Solutions Architect at Amazon Web Services (AWS), where she helps public sector customers design and build secure, scalable solutions in the cloud. Before AWS she served almost 17 years in the military, and she brings that experience of high-stakes, mission-focused work to every customer she supports.
Mike is Technical Director at Scale Factory, an AWS Premier Tier Consulting Partner, and an AWS Ambassador. He joined in 2014 as a hands-on engineer, delivering large scale AWS migrations, and has since moved into leadership. Today he leads the technical side of Scale Factory’s AWS partnership, speaks regularly at conferences, and keeps the organisation aligned with the latest technology trends. His expertise continues to drive both client success and the team’s technical direction.
Do you have a story to share? If you are interested in speaking at one of our events, please check out our call for papers.

We are advocates for greater inclusion & diversity in UK Tech and are especially keen to receive talk submissions from people in underrepresented groups. If you are interested in speaking at a future meetup but would like to discuss what to expect or need assistance, please contact our Inclusion & Diversity Lead Natalie Gray - [graynataliej@gmail.com](mailto:graynataliej@gmail.com) or DM her @natjgray

Check out our website for more information about our community and our code of conduct. Remember to follow us @AWSUserGroupUK and on LinkedIn for the latest updates, and you can find videos of our past meetups here.