Series B Fintech Startup
Building a Real-Time Payment Processing Platform That Handles Millions
How we helped a Series B fintech startup rebuild their payment processing engine to handle 3x volume while reducing transaction times by 60%.
60%
Reduction in transaction processing time
3x
Increase in throughput capacity
$840K
Saved annually vs. US hiring
The Challenge
The client's existing payment processing system was built on a monolithic architecture that couldn't scale beyond 500 transactions per second. As they closed their Series B round and prepared for rapid growth across Latin America, they faced constant timeout errors during peak hours, slow settlement times averaging 4.2 seconds per transaction, and a codebase that made it nearly impossible to add new payment methods. Their two-person backend team was stretched thin, and hiring senior fintech engineers in the US was taking 4-6 months per role.
Our Solution
We embedded a team of 4 senior developers — 2 Node.js backend engineers, 1 React frontend specialist, and 1 DevOps/infrastructure engineer — into their existing squad within 12 days. The team decomposed the monolith into event-driven microservices using Node.js and PostgreSQL, implemented an optimistic locking strategy for concurrent transaction handling, built a real-time monitoring dashboard in React with WebSocket feeds, and set up auto-scaling infrastructure on AWS with blue-green deployments. Our engineers worked in their timezone (CST), attended daily standups, and paired with their existing team to ensure full knowledge transfer.
Tech Stack
"Quo's team ramped up faster than any hire we've made. Within the first sprint they were shipping production code, and by month two they'd redesigned our entire transaction pipeline. The 60% speed improvement directly impacted our conversion rates."
David Chen
CTO, Series B Fintech Startup
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