hey, i'm
Vihan Rojitha
I work with
Featured Projects
Real-world work delivered through freelance engagements and professional roles.
Sales & Inventory Management System
T-Shirt Design Studio - 3D Design Platform
ZapTech E-Commerce Web App
Eat-n-Split Web App
Crypto Code Landing Web Page
Professional Experience
Apex Software Solutions
Feb 2025 - Present
Software Engineer
- -Designed a fine-grained RBAC system with 0+ granular permissions, per-user-per-branch overrides, and supervisor delegation flow using Spring AOP and custom @PreAuthorize-style annotations.
- -Implemented a centralized audit trail across 0+ service mutations using a custom AOP annotation with method-level interception and structured JSON logging.
- -Replaced direct SMS calls with an event-driven domain model (Spring ApplicationEvents, @TransactionalEventListener AFTER_COMMIT, async listeners) — fixing a real bug where async SMS fired on rolled-back transactions, and decoupling business services from notification logic entirely.
- -Architected a pluggable SMS provider system (@ConditionalOnProperty, Strategy pattern) with fail-fast misconfiguration detection — adding a new gateway requires one class, zero changes to business code.
- -Built a multi-branch healthcare channeling platform with doctor scheduling, OPD session management, appointment workflows, and real-time cashier session reconciliation.
- -Chose a modular monolith over microservices for planned multi-module expansion — single JAR deployment, Spring @ConditionalOnProperty feature toggles per module, event-driven inter-module communication, with a clear extraction path if scale demands it.
- -Architected a multi-tenant Quality Control SaaS for medical labs with tenant-isolated RBAC, pro-rated subscription billing, automated invoice generation, and PayHere payment integration.
Freelance
Jan 2024 - Present
Full Stack Developer
Delivering modern web applications for UK and Sri Lankan clients. Built a multi-operator WhatsApp inbox using Evolution API and Supabase Realtime, and shipped SEO-optimized UK based recovery business site achieving #1 Google rankings.
Apex Software Solutions
Jan 2023 - Oct 2023
Junior Software Developer
Developed Java-based backend services and REST APIs following OOP principles. Designed ER diagrams and optimized database queries for performance, supporting business-critical workflows across multiple client deployments.
Apex Software Solutions
Sep 2022 - Dec 2022
Software Developer Intern
Assisted senior developers with backend feature development and bug fixes. Handled maintenance tickets and delivered user training sessions to ensure smooth adoption of internal systems.
About Me
I'm a backend engineer by day, AI-native builder by everything else. At Apex Software Solutions, I architect multi-tenant SaaS platforms in Java and Spring Boot. On the side, I ship AI-powered web applications for clients across the UK and Sri Lanka — from custom WhatsApp inboxes to business sites that rank #1 on Google through technical SEO and performance-driven builds.
What I care about: building software that holds up under real-world load, not just demos. That means production-grade architecture (RBAC, event-driven systems, audit trails) paired with AI tooling that actually ships — Claude Code, RAG, multi-agent workflows, MCP servers. The boring engineering and the cutting-edge AI, used together.
Based in Sri Lanka, working with clients globally. Currently open to freelance projects and selective full-time opportunities in AI-native engineering roles.
see my education and certifications ➔