Re-Architecting a Fintech for $2.3B in Volume
Rebuilding core transaction infrastructure for a Series A fintech — with zero downtime during migration.
Re-Architecting a Fintech for $2.3B in Volume
Nexus Capital had outgrown a transaction platform assembled from early-stage compromises. It was time for a ground-up rebuild — without disrupting live transaction flow.
Response times had passed 8 seconds and incidents were rising. The platform had to handle $1B+ in daily volume, meet new regulatory requirements, and give the engineering team a foundation they could build on.
Architecture before code: two weeks mapping every flow and dependency, then an event-driven redesign with Redis-backed caching and a first-principles PostgreSQL schema. Old and new ran in parallel for three weeks with automated consistency checks.
Launched in 14 weeks with zero downtime. Response times fell from 8.2s to under 1s and the platform now absorbs 10x the previous peak load.
A real-time observability dashboard gave the team full visibility into transaction health — with no dependence on third-party tooling they don’t control.
They navigated a complex, sensitive migration without drama. Methodical, honest about risks, and always proactive. Our operations team is genuinely delighted with the new system.
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