Oshan Ranasinghe

Experience

Engineering experience across backend, distributed, and AI-enabled systems.

My professional work spans customer-facing backend development and R&D engineering. Across both, I've worked close to the implementation layer: building application features, integrating services, tracing distributed execution, and turning technical requirements into working software.

Jan 2025 – Present
Colombo, Sri Lanka

AI Engineer

Treeloq ↗

Designing agentic AI workflow automation for multi-step business processes using Python, FastAPI, LangGraph, LLM tool calling, structured outputs, and external APIs, moving workflow state and tool orchestration into reusable AI services.

  • →Building RAG and semantic-retrieval components with PostgreSQL/pgvector and grounded generation to address fragmented knowledge and improve how applications retrieve context before producing LLM responses.
  • →Engineering reusable AI backend services with explicit state, validation, asynchronous execution, persistence, and REST interfaces so LLM and agent capabilities can be integrated cleanly into existing software systems.
  • →Applying evaluation, tracing, and observability with OpenTelemetry, structured logging, and automated testing to inspect multi-step agent behavior, diagnose failures, and make AI workflows easier to iterate on.
  • →Containerizing AI services with Docker and maintaining reproducible development workflows, helping move AI functionality from experimentation toward production-oriented application integration.

Python · FastAPI · LangGraph · PostgreSQL/pgvector · OpenTelemetry · Docker · REST APIs

Feb 2025 – Jan 2026
University of Ruhuna

Chairman

IEEE Computer Society Student Branch

Held leadership or team-lead responsibilities across more than six university events, and contributed as a core member of HaXtreme, leading technical positioning and organization for HaXtreme 2.0.

Leadership · Event Organization

Jul 2024 – Jan 2025
Colombo, Sri Lanka

Research Development Software Engineer

CodeGen International

Instrumented an existing Java/Python multi-agent orchestration framework with 10–12+ interacting agents for end-to-end distributed tracing, and built distributed agent-system components including RabbitMQ messaging, gRPC communication, and RAG components using Weaviate.

  • →End-to-end tracing across the orchestration framework with OpenTelemetry, Jaeger, and Grafana.
  • →GitLab CI/CD workflows, Docker, and Kubernetes-based environments.

Python · Java · RabbitMQ · gRPC · OpenTelemetry · Weaviate · Docker · GitLab CI/CD

Nov 2019 – May 2023
Badulla, Sri Lanka

Back-End Developer

Treeloq · formerly Priwoo

Primary backend contributor on customer-facing web applications, taking features from requirement analysis through implementation — REST APIs, JWT authentication, database models, and third-party integrations.

  • →Serverless workflows on AWS Lambda and PDF-generation pipelines with Puppeteer.
  • →Node.js/Express.js/MongoDB features for client-facing business applications.

Node.js · Express.js · MongoDB · React · REST APIs · JWT · AWS Lambda · Puppeteer

See the systems behind the experience

My project case studies show architecture, implementation decisions, and engineering trade-offs.