Gathiira Mwangi — Backend Engineer

Profile

Backend Engineer with 5+ years building reliable, high-performance services for critical financial services platforms. Hands-on with Java, Spring Boot and Spring WebFlux for reactive, non-blocking microservices, and with RESTful and event-driven APIs built on Kafka and RabbitMQ. Experienced designing resilient distributed systems with idempotency, eventual consistency and fault tolerance at the core, integrating banking and mobile money systems that process real-time transactions. Strong advocate for clean code, test-driven development, and automated CI/CD, working closely with senior engineers and product teams to deliver high-quality, secure software.

Technical Skills

Languages

JavaKotlinPythonTypeScript

Backend & Frameworks

Spring BootSpring WebFluxDjango REST FrameworkRESTgRPCNext.js

Messaging & Streaming

KafkaRabbitMQAMQP

Distributed Systems

MicroservicesEvent-Driven DesignIdempotencyEventual ConsistencyFault ToleranceHigh Availability

Databases

PostgreSQLMySQLMS SQLMongoDBRedisFlywayLiquibase

Cloud-Native Security

OAuth 2.0Secrets ManagementEncryption At Rest/In Transit

DevOps & Cloud

DockerKubernetesAWSAzureGitHub ActionsArgoCD

Testing & Quality

JUnit 5MockitoTestcontainersTDDPerformance Testing

Observability

SentryProactive MonitoringIncident ResponseLogging

Practices

Code ReviewDocumentationAgile

Key Capabilities & Impact

Capability	Impact
Production Java/Spring Boot at scale	5+ years shipping Spring Boot microservices powering digital banking, KYC, wallet and payment workflows at Paycloud Africa.
Microservices & event-driven architecture	Architected high-throughput REST APIs and asynchronous, event-driven microservices for real-time payment processing.
Event streaming & asynchronous messaging (Kafka/RabbitMQ)	Specialized in Kafka for event streaming and RabbitMQ/AMQP for reliable, async inter-service communication across distributed systems.
Idempotency, eventual consistency & fault tolerance	Designed idempotent processing and retry mechanisms that eliminated duplicate-transaction risk and cut payment-workflow bottlenecks.
Relational data modeling	Built and optimized PostgreSQL/MySQL-backed services across loan, payment and ERP integration systems.
Caching & containerization	Used Redis for caching and queue optimization, and Docker for consistent, containerized deployments.
Cloud infrastructure & CI/CD	Automated deployments and CI/CD on Azure-hosted infrastructure using GitHub Actions and ArgoCD.
Test-driven reliability	Safeguarded payment and onboarding workflows with unit, integration and performance tests using JUnit and Mockito.

Work Experience

Software Engineer 01/2024 – Present

Paycloud Africa Limited · Java, Spring Boot, RabbitMQ, Redis, MySQL, Next.js, Docker, K8s

Architect event-driven microservices in Java and Spring Boot supporting digital banking, merchant onboarding, KYC workflows, wallet operations, and payment processing.
Build high-throughput RESTful APIs handling financial transactions and real-time payment workflows, designed for high availability and resilience under load.
Implement asynchronous, event-driven communication between microservices using RabbitMQ and AMQP, specializing in messaging and distributed systems.
Design resilient microservices with idempotent processing, retry mechanisms and fault-tolerant patterns for asynchronous payment workflows, preserving data integrity.
Write unit, integration and performance tests using JUnit and Mockito to ensure reliability of payment and onboarding workflows.
Collaborate with DevOps, Product, QA and Ops to improve CI/CD pipelines via GitHub Actions and ArgoCD.

Software Engineer (Contract) 02/2025 – 10/2025

Digital Distribution Solutions · Kotlin, Spring Boot, Redis, Odoo, SAP, M-Pesa APIs, Docker

Designed and implemented ERP integrations (Odoo & SAP) to unify order placement, automate sales logistics and digitize payment collection via M-Pesa.
Introduced a cashless payment collection module, improving transaction reliability and high availability of reconciliation workflows.
Built scalable backend services in Kotlin + Spring Boot, with proactive monitoring across key service endpoints.
Reduced reconciliation errors and gave real-time visibility across sales and inventory, working with cross-functional Product and Ops teams.

Fullstack Developer 02/2022 – 12/2023

LipaLater · Java, Spring Boot, RabbitMQ, Redis, MySQL, Next.js, Docker, K8s

Built scalable loan management services using Java and Spring Boot microservices, optimizing performance and reliability across distributed workflows.
Designed RESTful APIs for loan allocation, repayment scheduling and customer lifecycle management.
Developed an online loan application portal using Next.js, improving borrower onboarding.
Optimized backend services using asynchronous processing patterns with RabbitMQ and Redis, improving loan processing efficiency by 30%.
Implemented containerized deployments with Docker and GitHub Actions to streamline CI/CD.

Back End Developer 09/2020 – 02/2022

Konza Silicon Company · Python, Django, Redis, PostgreSQL, Nginx

Developed REST APIs for authentication and land administration microservices using Python and Django REST Framework.
Configured and managed Nginx for load balancing, reverse proxy and caching to support high-availability services.
Contributed to the Ardhisasa land digitization platform; mentored junior team members through debugging and code reviews.

Education

Bachelor of Science, Mathematics and Computer Science

Jomo Kenyatta University of Agriculture and Technology, Kenya

References

James Mwai

CTO & Co-Founder, Paycloud Africa · james@paycloudafrica.com