Pethum Jeewantha

Galle, Sri Lanka

Hi, I'm Pethum Jeewantha.
Full-Stack Software Engineer

I build scalable, user-focused applications and enjoy exploring emerging technologies - from AI-powered tools to cloud-native systems.

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Get to know me

About

I'm a Full-Stack Software Engineer based in Galle, Sri Lanka, with 5+ years of experience across cloud-native architecture, AI-driven product development and DevOps. I currently lead a team building a production-grade accounting SaaS.

My work spans backend services in Go, Java (Spring Boot), Laravel and Node.js, modern frontends in React, Angular and Next.js, and cloud-native delivery with Docker, Kubernetes and AWS. I also design agentic AI and ML workflows with tools like LangChain, LangGraph and CrewAI, turning complex problems into clean, maintainable systems.

I hold a BSc in Computer Science from the University of Kelaniya and industry certifications in AWS, Kubernetes, Terraform and Java. I'm an active contributor to the developer community through Kubernetes Community Days (KCD) Sri Lanka, including as a guest speaker.

What I work with

Skills & Technologies

A snapshot of the languages, frameworks and tools I use to design, build and ship software.

Languages
GoJavaC#TypeScriptJavaScriptSQLPHPPythonDart
Frameworks & Frontend
Next.jsReactAngularReduxSpring BootLaravel.NETNode.jsFlutterTailwind CSS
AI/ML & Integrations
LangChainLangGraphCrewAIMachine LearningOpenAIAssemblyAI
DevOps & Cloud
DockerKubernetesTerraformAWSGoogle CloudAzureDigital OceanCI/CDGrafanaPrometheus
Databases
MySQLMSSQLMongoDBRedisFirebase

Verified expertise

Certifications

Industry certifications across cloud, containers, infrastructure and programming.

AWS Certified Solutions Architect – Associate badge

AWS Certified Solutions Architect – Associate

Amazon Web Services

Certified Kubernetes Administrator badge

Certified Kubernetes Administrator

The Linux Foundation / CNCF

HashiCorp Certified: Terraform Associate badge

HashiCorp Certified: Terraform Associate

HashiCorp

Oracle Certified Associate, Java SE 8 Programmer badge

Oracle Certified Associate, Java SE 8 Programmer

Oracle

Selected work

Projects

A selection of things I've built - from AI tooling to full-stack apps. More on my GitHub.

KrackAI
An AI-powered app that helps users crack live online interviews, pairing real-time speech-to-text transcription with AI-driven response analysis for instant feedback.
Next.jsLangChainAssemblyAIOpenAI
Fitness SaaS Platform
Cross-platform fitness tracking and management across mobile and web, with push notifications and in-app support to boost user engagement.
ReactFlutterASP.NET CoreOneSignal
Pharmacy Wholesale B2B
A cross-platform B2B ordering and distribution platform for pharmacy wholesale, spanning mobile and web with robust order-processing services.
Next.jsFlutterASP.NET Core
AI Slack Bot
An AI-powered Slack chatbot that uses an answer engine to converse with users in natural language, written in Go.
GoAISlack API
Code
Broadcast Hub
A general-purpose WebSocket server in Go built on the Fiber framework for real-time, bidirectional communication.
GoFiberWebSockets
Java ORM Framework
A lightweight Java 8 ORM that auto-generates database tables from annotated classes using reflection.
JavaReflectionAnnotations
Next.js Issue Tracker
A full-stack issue tracking and project management app with real-time updates over WebSockets.
Next.jsTypeScriptWebSockets
Code
POS System
A point-of-sale system built on the AdminLTE template with paginated data tables for products and sales.
HTMLCSSJavaScript
Code
Google Clone
A pixel-accurate Google search clone with integrated search functionality, built with vanilla HTML/CSS.
HTMLCSSJavaScript
Code
Twitter Clone
A responsive replica of the Twitter news feed UI built from scratch with vanilla HTML and CSS.
HTMLCSS
Code
Text Editor
A desktop text editor application with core editing functionality, written in Java.
JavaSwing
Code

My journey

Experience & Education

Experience

  1. Senior Software Engineer

    Nov 2024 - Present

    Balnzed

    Lead a team building a cloud-based accounting SaaS - overseeing architecture, code reviews and sprint planning while designing agentic AI workflows and ML features on a scalable microservices backend, and establishing cloud infrastructure and CI/CD.

  2. Senior Software Engineer

    Jun 2024 - Nov 2024

    Bitzify

    Built core accounting and AI-assisted features for a product serving 1000+ businesses, running multi-cloud infrastructure with monitoring and observability to reduce incident detection time.

  3. Software Engineer

    May 2022 - May 2024

    Bitzify

    Delivered full-stack payroll (IFS integration), warehouse and investment-management systems - including automated background jobs that process ~1,500 employees in under 5 minutes.

  4. Associate Software Engineer

    Jan 2022 - Mar 2022

    Bitzify

    Built a full-stack Excel add-in integrating with Acumatica over Open API.

  5. Trainee Software Engineer

    Apr 2021 - Dec 2022

    Institute of Software Engineering

    Built a full-stack student management system with a secure, tested backend, deployed as a PWA on AWS for a consistent, app-like experience.

Education

  1. BSc (Hons) in Computer Science

    University of Kelaniya

    Studied algorithms, software engineering and modern application development.

  2. GCE Advanced Level - Physical Science

    2020

    St. Aloysius' College, Galle

    Physical Science stream (Z-score 1.659).

Let's talk

Get in touch

Have a project in mind, a role to fill, or just want to say hi? Drop me a message.

I'm open to freelance work, full-time roles and interesting collaborations. You can reach me through any of these: