Pavithra Ranasinghe

Senior Software Engineer at Altrium (Private) Limited

Designed and maintained scalable backend services using Java 21 and Spring Boot for a US-based health insurance SaaS platform serving 1M+ users. Contributed to architecture decisions and sprint planning within an 8-member microteam. Led backend implementation of an event-driven email processing pipeline (SES → S3 → SQS → Spring Boot). Processed ~5,000 emails/day with architecture targeting scalability to millions. Designed and implemented real-time status propagation for asynchronous document processing jobs using MongoDB change streams and Pub/Sub-based WebSocket/SSE, achieving sub-500 ms client updates. Optimized MongoDB aggregation queries and indexing strategies, reducing latency from ~2 seconds to sub-second. Acted as a production support engineer, performing debugging and root-cause analysis during live incidents. Mentored 2 junior engineers and conducted regular code reviews.

Senior Software Engineer at Zero Day Security (Private) Limited

Designed and implemented schema-based multi-tenant architecture using PostgreSQL. Built dynamic tenant provisioning with automated schema creation per tenant. Backend services support 10 active tenants (scalable to 50+). Designed and maintained RESTful backend services, including geolocation functionality via PostgreGIS. Collaborated on full-stack features with Angular and React Native.

Senior Software Engineer at Alterium (Private) Limited

US-based health insurance SaaS platform serving 1M users. Designed and maintained scalable backend services using Java 21 and Spring Boot. Contributed to architecture decisions and sprint planning within an 8-member micro team. Led backend implementation of an event-driven email processing pipeline (SES → S3 → SQS → Spring Boot). Processed 5,000 emails/day with architecture targeting scalability to millions. Designed and implemented real-time status propagation for asynchronous document processing jobs using MongoDB change streams and Pub/Sub-based WebSockets/SSE, achieving sub-500 ms client updates. Optimized MongoDB aggregation queries and indexing strategies, reducing database latency from 2 seconds to sub-second. Acted as a support engineer, performed production debugging and root-cause analysis during live incidents. Actively mentored 2 junior engineers and conducted regular code reviews.