Roobanraj.dev
✦ Available for Projects

Hi, I'm
Roobanraj K

I am a

Crafting high-performance mobile applications and enterprise-grade full-stack web platforms. Expert in offline-first systems, secure billing networks, and cloud integrations.

4.5+
Years
Experience
15+
Projects
Delivered

About Me

Get to know me and my professional journey.

Senior Software Engineer — Mobile & Full-Stack Web

I am a Senior Software Engineer with around 4.5 years of experience specializing in both high-performance mobile application development and enterprise-grade full-stack web applications.

My expertise spans building native Android and smart POS ticketing applications (Java/Kotlin, SQLite, payment gateways) as well as architecting modern web platforms, online printing marketplaces, and billing SaaS applications (React, Next.js, REST APIs).

I focus on writing clean, maintainable, and highly secure code, executing VAPT audit requirements, optimizing performance, and delivering robust offline-first and cloud synchronization systems that serve millions of transactions daily.

Passionate about pushing the boundaries of technology, I thrive on solving complex engineering challenges and transforming ideas into scalable, production-ready products that make a real impact.

4.5+

Years Experience

15+

Projects Completed

12+

Apps Developed

3+

Organizations

Technical Skills

My toolbox for building high-performance mobile applications and modern web systems.

Mobile & POS Development

Java & Kotlin
Expert
Jetpack Compose & XML
Expert
Android SDK & POS APIs
Expert
Offline SQL / SQLite
Advanced

Web & Full-Stack

React & Next.js
Advanced
Node.js & REST APIs
Advanced
HTML5 / CSS3 / Tailwind
Expert
SOAP & XML Web Services
Advanced

Libraries & Architecture

MVC / MVP / MVVM
Expert
Payment Gateways
Expert
Retrofit / Axios / Volley
Advanced
Firebase Services
Advanced

Tools & Testing Security

Android Studio & VS Code
Expert
Postman & DB Viewer
Expert
VAPT / Security Audits
Advanced
Git & Version Control
Advanced

Professional Experience

My career journey and professional background.

Founder & Lead Full-Stack Architect

Knewrix (SaaS Startup) | Bengaluru, Karnataka
01/2023 - Present
  • Knewrix Billing: Architected and engineered a comprehensive cloud-based SaaS billing and ERP platform incorporating smart POS, invoicing, stock transfers, payroll, and automated e-Invoicing/GST compliance reporting.
  • AmazoPrint: Built an online printing marketplace with an integrated browser design studio, providing real-time quotes, templates, and pan-India print partner fulfillment.
  • Dum Darbar: Designed a restaurant operations platform to simplify billing, purchase, inventory control, and business analytics for food service businesses.
  • Enterprise Web Solutions: Delivered end-to-end full-stack web systems, RESTful API platforms, CRM campaigns, and SEO-optimized growth portfolios using React, Next.js, and Node.js.

Senior Software Engineer - Lending Solutions

Craft Silicon Pvt. Ltd. | Bengaluru, Karnataka
01/2025 - Present
  • GLOW (Group Loan Origination Workflow): Developed and scaled a comprehensive loan origination platform for banks and microfinance institutions, digitizing customer onboarding, eKYC, and automated credit bureau integration.
  • TruCell (Field Operations): Engineered a mobile-first field banking solution enabling loan officers to handle doorstep collections, real-time receipts, offline data capture, and cash reconciliation.
  • Core Banking Integrations: Integrated field banking operations with core banking backends, improving loan processing productivity, field tracking, and operational compliance.

Senior Android & POS Engineer

Radiant Info Systems Ltd | Bengaluru, Karnataka
09/2021 - 01/2025
  • Online Passenger Reservation Systems: Developed and deployed mobile bus ticket reservation apps for State Transport Corporations (TNSTC, GSRTC, OSRTC) and private operators (BUSINDIA), serving thousands of travelers.
  • Transit POS Solutions: Designed ticketing applications running on Pine Labs, Paytm, and World Line ETM machines for on-route buses (TNSTC US, GSRTC, UDUPI ETM). Implemented robust offline-first SQLite synchronization processing over 1 crore transactions daily.
  • Chaloyaar.com Platform: Lead a team of 6 engineers to build a private bus booking aggregator integrating Bitla, EzeeInfo, and NueGo APIs, alongside the admin portal and RESTful APIs.
  • Payment Gateways & Integrations: Integrated secure payment architectures including RazorPay, CCAvenue, Bill desk, Paytm, Axis, and ICICI bank gateways.
  • Security Audits & Optimization: Passed rigorous VAPT (Vulnerability Assessment and Penetration Testing) audits, eliminated memory leaks on rooted devices, and enhanced production safety.

Featured Projects

A selection of my recent professional full-stack web and native mobile work.

GLOW (Group Loan Origination Workflow) 3D Mockup

GLOW (Group Loan Origination Workflow)

A comprehensive loan origination platform for banks and microfinance institutions (MFIs) that digitizes group lending, field surveys, eKYC verification, and automated underwriting workflows.

React.jsNext.jsNode.jseKYC APIsCore Banking
TruCell (Field Operations Solution) 3D Mockup

TruCell (Field Operations Solution)

A mobile-first field operations application that enables field loan officers to perform collections, repayments, GPS-based customer inspections, and offline data synchronization with central core banking systems.

KotlinAndroid SDKSQLite DatabaseGPS Tracking
Knewrix Billing 3D Mockup

Knewrix Billing

A cloud-based SaaS billing and ledger management ERP platform built for retailers, wholesalers, and SMEs. Combines invoice billing, stock control, accounting, GST automated e-Invoicing, payroll, WhatsApp campaigns, and business analytics in a unified dashboard.

Next.jsReact.jsNode.jsPostgreSQLGST APIs
Online Passenger Reservation System 3D Mockup

Online Passenger Reservation System

A mobile application designed to facilitate online bus ticket reservations for major Indian State Transport Corporations (TNSTC, GSRTC, OSRTC) and private operators (BUSINDIA). Offers comprehensive details about bus schedules, seat layouts, fares, discounts, and high-security payment integrations.

KotlinAndroid StudioSOAP & RESTPayment Gateways
Smart Transit POS Solutions 3D Mockup

Smart Transit POS Solutions

A robust smart ticketing application running on handheld POS devices (including Pine Labs, Paytm, and World Line ETM terminals) for on-route buses across multiple state corporations (TNSTC US, GSRTC, UDUPI ETM). Implements secure local SQLite database storage to queue ticket sales offline and sync when online, facilitating over 1 crore transactions daily.

JavaAndroid SDKSQLite DatabasesPOS Hardware APIs
AmazoPrint 3D Mockup

AmazoPrint

An online printing marketplace connecting customers, designers, and printing service providers across India. Features an integrated browser-based design canvas with drag-and-drop templates, real-time printing quotes, and order fulfillment workflows.

React.jsNext.jsHTML5 CanvasTailwind CSS
Dum Darbar 3D Mockup

Dum Darbar

A hotel and restaurant operations management SaaS designed to simplify daily dining, billing, and inventory administration. Streamlines food service invoicing, real-time stock control, purchase tracking, and multi-branch sales reporting.

React.jsNext.jsNode.jsMySQLPOS Billing
Chaloyaar.com Platform 3D Mockup

Chaloyaar.com Platform

A multi-faceted booking ecosystem integrating several private bus reservation systems in India (Bitla, EzeeInfo, NueGo API). Comprises the main passenger portal (Chaloyaar.com), administrative management portal (Chaloyaar Admin), and robust RESTful APIs (Chaloyaar API) serving Android and iOS clients.

JavaIntelliJ IDE & EclipseREST APIsAdmin Dashboard
Knewrix Portal 3D Mockup

Knewrix Portal

An enterprise web application and marketing portal for Knewrix. Showcases digital growth consultancy, custom software services, digital SEO-focused solutions, and client growth analytics dashboards.

Next.jsReact.jsTailwind CSSFramer Motion

Services

What I can do for you and your business.

Android App Development

Building scalable, native Android applications from scratch with modern architectures and offline-first capabilities.

UI Development

Creating pixel-perfect, responsive UI with Jetpack Compose, React, and Next.js for both mobile and web.

API Integration

Seamless integration of complex REST/SOAP APIs, payment gateways, and third-party backend services.

Performance Optimization

Enhancing app speed, reducing memory footprint, eliminating leaks, and improving end-user experience.

Bug Fixing & Maintenance

Identifying, troubleshooting, and resolving critical application bugs across production environments.

Play Store Publishing

End-to-end support for deploying apps to Google Play Store with optimization for reviews and ratings.

SaaS Platform Development

Architecting full-featured SaaS applications with billing, multi-tenancy, analytics, and compliance features.

Cloud & DevOps Integration

Setting up cloud hosting, CI/CD pipelines, Firebase services, and scalable server infrastructure.

0+
Projects Completed
0M+
Daily Transactions
0%
VAPT Security Score
0.5+
Years Experience

Education

My academic background and qualifications.

B.E. Mechanical Engineering

Roever Engineering College

2018 - 2021 8.40 CGPA

Completed engineering degree with distinction. Developed strong analytical and problem-solving skills that translate directly to software architecture.

Diploma in Mechanical Engineering

Thanthai Hans Roever Polytechnic College

2015 - 2018 94%

Graduated with outstanding academic performance. Built the foundation for systematic thinking and structured engineering approaches.

Secondary School (SSLC)

Thanthai Hans Roever Higher Secondary School

2014 - 2015 86%

Completed general secondary education with strong focus on mathematics and science.

Methodology & Key Focus

Core operational disciplines ensuring production safety, app security, and high performance.

Production Safety

Zero Crash Policy

Responsible for complete project production safety. Ensuring stable deployments across transit fleets through rigorous integration testing, rollback strategies, and automated builds.

Transit OperationsMission Critical

Security & VAPT Vetting

Vulnerability Auditing

Cracking application vulnerability assessments and black box tests. Designing defensive architectures to prevent memory leaks and API tampering, especially on rooted POS and mobile devices.

Device SecurityVAPT Cracked

Offline-First Architectures

Data Synchronization

Structuring offline local SQLite database synchronization. Queuing local ticketing actions and securely pushing data to SOAP and RESTful servers when connectivity is restored.

Offline DatabaseSync Enabled

Get In Touch

Have a project in mind or want to collaborate? Let's talk!

Contact Information

Fill out the form and I will get back to you within 24 hours. Alternatively, you can reach out to me directly via email or phone.

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