Pasindu Lanka
100K+ scale · real-time · event-driven · AWS.
Overview
Software Engineer @Metarune Labs
Social Links
About
- 3+ years designing and scaling distributed systems for real-time applications at 100K+ user scale and $10M+ revenue impact. Specialized in event-driven architectures, serverless systems, and real-time communication using AWS and modern full-stack technologies — leading teams, owning architecture, and shipping under production constraints.
- Metarune Labs — Software Engineer (Apr 2023 – present); Trainee Software Engineer (Feb – Apr 2023): architected full-stack features for a real-time chat platform; event-driven serverless workflows (AWS Lambda, SQS); led a frontend team of 7+ engineers (PR standards, quality, mentoring); React Native mobile apps; Unity (C#) and Node.js for gameplay and backend; Jest, Vitest, and Playwright across frontend and backend.
- SLIIT — B.Sc. in Software Engineering, expected 2027. Relevant coursework: Distributed Systems, Software Architecture, Application Frameworks, Data Structures & Algorithms.
- Based in Colombo, Sri Lanka.
Experience
- Architected and delivered full-stack features for a real-time chat platform serving 100K+ users, contributing to $10M+ revenue impact.
- Designed and implemented event-driven serverless workflows (AWS Lambda, SQS) to improve scalability and reliability under high load.
- Led a frontend team of 7+ engineers — PR standards, code quality, and mentoring junior developers.
- React Native cross-platform mobile apps; Unity (C#) and Node.js for gameplay and backend systems.
- Jest, Vitest, and Playwright for unit and end-to-end testing across frontend and backend.
- AWS
- React
- React Native
- Next.js
- Node.js
- TypeScript
- Unity
- C#
- PostgreSQL
- Redis
- Jest
- Vitest
- Playwright
- Next.js
- TypeScript
- Node.js
- React Native
Education
- Distributed Systems
- Software Architecture
- Algorithms
- Software Engineering
Projects(5)
Full-stack app for construction project lifecycle, real-time sustainability metrics, document compliance, and resource management.
- Express
- TypeScript
- MongoDB
- React
- Vite
- Turborepo
- JWT
- Google Maps
- Cloudinary
GitHub Contributions
Stack
Languages
Frontend / mobile
Databases
Cloud & DevOps
Testing & observability
Blog(4)
Case studies(14)
Integrating an LLM Without Letting It Own Your Architecture
Adding an LLM-powered feature while keeping it a swappable component — API abstraction, timeout handling, output validation, and prompt versioning.
One Database, Five Products: Designing Multi-Tenancy Without a Framework
How we isolated five client products in a single PostgreSQL database using row-level tenant_id and shared schema — and why we skipped off-the-shelf multi-tenant frameworks.
Cost Control for AI-Backed Features: Token Budgets and Semantic Caching
Reducing LLM API spend without degrading UX — semantic caching, per-tenant token budgets, and model selection by task complexity.
When to Cache and When to Query: Drawing the Line with Redis and PostgreSQL
Defining a caching strategy for a multi-tenant platform — what to cache, when to invalidate, and when to always hit the database.