FinTech · Personal Finance Platform
A B2B/B2C personal finance platform used by digital banks, where a rounding error is a customer complaint and downtime is a headline.
Financial events per day
Across a three-broker Kafka cluster
Databases unified
PostgreSQL, MongoDB, MySQL, Oracle and SQL Server
Lower read latency
From a Redis cache-first strategy
Hysab Kytab gives banking customers a single view of their money, covering balances, spending, categories and insights, aggregated across multiple banks. It is delivered to digital banking leaders including Temenos and Interswitch, which means it inherits their reliability expectations rather than a startup’s.
The core difficulty was consolidation. Every upstream source had its own database, its own format and its own idea of when data is correct: PostgreSQL, MongoDB, MySQL, Oracle and SQL Server all had to end up behind one coherent service layer without losing precision or slowing the app down.
I architected a distributed microservices ecosystem in Golang and NestJS, using Golang for the performance-critical core services and event-driven processing to keep aggregation off the request path entirely.
Five database engines and multiple bank feeds had to become one low-latency, consistent financial picture.
Financial data tolerates no drift, while still serving customer-facing apps at interactive speed.
High availability and data integrity expectations set by enterprise banking clients, not by us.
A polyglot backend hidden behind one coherent service layer, so the banking app never has to know which engine an answer came from.
B2B bank integrations and B2C apps
gRPC between services, REST at the edge
100K+ financial events per day
Five engines, one service contract
Aggregation is slow and unpredictable; customer apps are neither. The whole design separates those two realities so the slow half never blocks the fast half.
Connectors pull account and transaction data from multiple banking sources, each with its own format and refresh cadence.
End-to-end encryption in Golang protects financial payloads in transit across service boundaries.
Over 100,000 financial events a day flow through a three-broker cluster feeding monitoring, audit trails and real-time alerting.
NestJS, Golang and Spring Boot services communicate over gRPC, coordinated through Kafka and RabbitMQ.
PostgreSQL, MongoDB, Oracle and SQL Server unified behind one cohesive service layer, each used where it is genuinely the right tool.
LangChain RAG pipelines and a Shariah-compliant multi-agent advisory chatbot turn raw transactions into guidance.
A Redis cache-first read strategy cut average read latency by more than 60%, keeping the customer app responsive.
Core services
Golang
High-performance communication and predictable latency for the services on the critical financial path.
Event processing
Kafka + RabbitMQ
Kafka for the durable, replayable event backbone; RabbitMQ for targeted fan-out where routing matters more than retention.
Read performance
Redis cache-first
Aggregated financial views are read far more often than they change, making caching the highest-leverage optimisation available.
Persistence
Polyglot by design
Bank integrations dictated the engines; the service layer absorbed that complexity so product teams never had to.
Maintained across a five-engine database landscape serving financial applications.
A Redis cache-first strategy measurably improved the customer-facing experience.
GCP infrastructure optimisation and better observability, with no loss of reliability.
Delivered to global digital banking leaders including Temenos and Interswitch.
If any of the problems above look familiar, I can help, whether that's a full architecture or a second opinion on the one you have.
Open to remote and hybrid work worldwide