Looking for a job

Ioana Leahu

@ioanaleahu

Senior Software Engineer at Mambu modernizing Java payments services and accelerating delivery of a credit card authorization and clearing engine.

Romania

Message

At Mambu, I own end-to-end delivery of high-availability Java microservices and led the upgrade of the payments web service from Java 13 to 21 and Spring 6. I also accelerated implementation of a credit card authorization and clearing engine using Claude Code, Codex, and spec-driven development.

As a Software Engineer, I designed Java microservices and Kafka workflows connecting processors with core platforms. I used TDD and performance testing with Scala and Gatling, and supported multi-tenant deployments on AWS and Kubernetes.

Earlier at Mambu, I developed features, tests, and releases for a cards connector on Corezoid and created AWS Lambda functions for its integrations. I also taught computer science seminars and practical classes at the Faculty of Computer Science, Alexandru Ioan Cuza University of Iași.

Experience

Work history, roles, and key accomplishments

Current

Senior Software Engineer

Current

Mambu

Feb 2026 - Present (8 months)

Owned end-to-end delivery of high-availability Java microservices, led Java 13 to 21 and Spring 6 upgrade, and enhanced observability with CloudWatch and Dynatrace. Mentored mid/junior engineers and provided L3 production support.

Software Engineer

Mambu

Jul 2023 - Feb 2026 (2 years 7 months)

Designed and implemented scalable Java 17 microservices and Kafka event-driven workflows for payment integration. Applied TDD with JUnit, Testcontainers, and JBehave, and pioneered load/performance testing with Scala and Gatling.

Java Spring Boot Microservices Kafka AWS Kubernetes Helm Redis Junit Test Containers JBehave Test Driven Development Scala Gatling Snyk Feature Flags Secrets Management

Integration Engineer

Mambu

Jun 2021 - Jul 2023 (2 years 1 month)

Developed features, testing, and releases for the cards connector on a low-code platform (Corezoid). Ran load and performance tests, identified platform limitations, and created AWS Lambda functions for integrations.

Corezoid AWS Lambda Load Testing Performance Testing

Teaching Assistant

Alexandru Ioan Cuza University of Iași

Jan 2003 - Dec 2017 (14 years 11 months)

Taught seminars and practical classes for bachelor's students in Operating Systems, Information Security, Algebraic Foundations of Computer Science, and Decidability and Complexity.

Linux BASH C Infosec Algebraic Foundations Decidability Complexity