Centralizing core business operations while automating WhatsApp messaging via WATI, daily catalog syncing through Meta Business API, Google Drive image uploads, and Instagram publishing with Publer.

Overview

As operations scaled, managing sales, inventory numbers, and customer outreach across disconnected spreadsheets and chat windows was causing delays. We built SES ERP to bring inventory tracking, purchasing, and staff management into a single system. Alongside the core database operations, a major focus was automating external communication and media pipelines—including automated WhatsApp alerts for orders, daily WhatsApp catalog synchronization, cloud image storage, and social media posting.

Engineering Challenges

• Organizing inventory, billing, and order workflows into maintainable NestJS modules without data conflicts during concurrent transactions.
• Triggering transactional WhatsApp alerts via WATI reliably on order milestones without blocking dashboard HTTP responses.
• Keeping hundreds of product items, images, and prices dynamically synced to the WhatsApp Commerce catalog every single day via Meta's Business API.
• Uploading product and resource images directly to organized Google Drive folders via API and scheduling Instagram posts/stories through Publer with clean error handling.

Architectural Contributions & Implementation

[01] Modular NestJS Backend & Relational Schema

Architected NestJS service modules for inventory, billing, users, and RBAC permissions. Designed normalized PostgreSQL tables with transaction blocks so stock counts stay accurate.

[02] WATI WhatsApp Message Automation

Integrated WATI's REST APIs to automatically dispatch templated WhatsApp messages to customers when orders are confirmed, dispatched, or pending payment.

[03] Daily WhatsApp Catalog Sync via Meta API

Built a daily cron job that fetches updated inventory, pricing, and product images from PostgreSQL and syncs them directly into the WhatsApp Commerce Catalog using the Facebook Business / Meta Graph API.

[04] Google Drive API for Image Uploads

Integrated the Google Drive API to upload product and resource images directly into designated Drive folders, returning secure image URLs to display across product and project records.

[05] Publer API for Instagram Publishing

Integrated Publer's API to let staff schedule and publish feed posts and stories directly to Instagram from the ERP dashboard, keeping product promotions aligned with current stock.

Delivered Artifacts & Results

• Scalable NestJS API backend with clean modular architecture
• Next.js administrative web portal for operations, billing, and social tools
• Event-driven WATI WhatsApp notification system for customer updates
• Daily automated cron job syncing warehouse inventory to WhatsApp Catalog via Meta API
• Google Drive image upload pipeline with organized folder structures
• Instagram post and story publishing module powered by Publer API

About the Author: Kartik Butani is a Senior Software Engineer specializing in NestJS backends, React/Next.js platforms, and scalable data architectures. Explore more case studies at https://krbutani.in or connect on GitHub and LinkedIn.

Indian Railways SMMS mobile app gives field technicians offline maintenance forms, live station maps, and equipment failure reports on Android devices.

Overview

Signaling equipment keeps trains running safely. Indian Railways maintenance teams inspect track circuits, signals, and point machines daily. Because railway tracks often run through dead zones with no mobile reception, paper forms were previously used. We built the SMMS Flutter app to let technicians complete full inspection checklists on site with automatic sync once back online.

Engineering Challenges

• Field workers frequently lose cellular reception along track routes, meaning the app could never depend on an active internet connection to save data.
• Different equipment types require different inspection questions and checks, so the forms needed to render dynamically based on equipment type.
• Supervisors needed to view equipment issues across railway stations on a visual map without lag.

Architectural Contributions & Implementation

[01] Map Integration with Geoserver

Connected Geoserver map endpoints to display railway stations visually. Clicking any station marker opens a smooth slide window showing equipment status, similar to Google Maps.

[02] Offline-First Data Storage

Stored all pending inspection entries locally in SQLite. The app monitors network status and uploads queued inspections as soon as Wi-Fi or cellular data returns.

[03] Interactive Drill-down Charts

Built bar, line, and pie charts for failure analytics. Tapping any chart opens a secondary chart with granular sub-category details.

[04] Dynamic Form Fields

Wrote form generators that load custom input fields depending on whether a technician is inspecting an LED signal, battery bank, or point machine.

Delivered Artifacts & Results

• Complete Flutter mobile application for Android field devices
• Geoserver GIS map interface with interactive marker sliders
• Robust offline-to-online reconciliation engine
• Dynamic multi-tier inspection report and charting module

About the Author: Kartik Butani is a Senior Software Engineer specializing in NestJS backends, React/Next.js platforms, and scalable data architectures. Explore more case studies at https://krbutani.in or connect on GitHub and LinkedIn.

Magic Swap gives retail partners an easy way to verify customer discounts using QR codes while members access exclusive local offers.

Overview

Similar to platforms like CouponDunia, Magic Swap required a smooth experience for both shoppers and merchants. Shop owners needed to confirm active member subscriptions instantly at checkout, while sales agents needed a tool to onboard new vendors.

Engineering Challenges

• Building three separate app experiences without duplicating shared code and API communication logic.
• Making QR code scanning fast and foolproof during busy retail store hours.
• Handling instant SMS verification and payment gateway callbacks reliably.

Architectural Contributions & Implementation

[01] Three Dedicated App Workflows

Created tailored Flutter apps for Members, Partners, and Salespersons, sharing a clean component library across all three.

[02] Fast QR Code Scanning

Integrated a camera QR scanner that verifies customer membership validity in less than a second.

[03] Payment Gateway Setup

Added Razorpay checkout so members can purchase membership plans directly through UPI, cards, and net banking.

[04] Push Notifications via Firebase

Set up Firebase Cloud Messaging (FCM) to send notifications whenever stores publish new offers or flash discounts.

Delivered Artifacts & Results

• Magic Swap Member Android & iOS Mobile Applications
• Magic Swap Vendor & Salesperson Management Applications
• Web administration dashboard with analytics and offer moderation
• End-to-end Razorpay checkout and SMS verification flows

About the Author: Kartik Butani is a Senior Software Engineer specializing in NestJS backends, React/Next.js platforms, and scalable data architectures. Explore more case studies at https://krbutani.in or connect on GitHub and LinkedIn.

Custom ERP modules built with PHP and PostgreSQL to manage factory workflows, inventory, and staff rosters in Oman.

Overview

Industrial plastics manufacturing requires close tracking of raw plastic granules, machine run times, and finished goods inventory. We built custom modules to replace disjointed records with an integrated factory system.

Engineering Challenges

• Tracking material consumption against actual production output to identify waste.
• Managing multiple currencies and invoice printing formats for regional trade.
• Maintaining stable server uptime on on-premise CentOS machines.

Architectural Contributions & Implementation

[01] Production Tracking Modules

Created screens to log raw material batches, track daily machine production outputs, and report finished goods into warehouse stock.

[02] HRMS & Shift Rosters

Built staff management features for shift scheduling, attendance logging, and basic payroll calculations.

[03] CentOS Server Maintenance

Installed and configured web and database servers on CentOS, set up automated database backup cron jobs, and tuned PostgreSQL queries.

Delivered Artifacts & Results

• Full suite of ERP modules (Sales, Production, Inventory, HRMS)
• Custom invoice generation and receipt formatting engine
• Hardened production CentOS server deployment with automated backups
• Comprehensive user manuals and administrative training

About the Author: Kartik Butani is a Senior Software Engineer specializing in NestJS backends, React/Next.js platforms, and scalable data architectures. Explore more case studies at https://krbutani.in or connect on GitHub and LinkedIn.

A spatial mapping system that helps municipal teams upload land records, view boundaries, and run area queries on interactive maps.

Overview

Urban planning departments deal with thousands of land parcel drawings in different formats. They needed a centralized database where boundary files could be uploaded, verified, and displayed on a map for zoning checks.

Engineering Challenges

• Handling complex polygon coordinate files without slowing down database queries.
• Validating uploaded boundary files to catch overlapping lines or incorrect coordinate systems.
• Giving non-technical government staff a clear web map interface to inspect property limits.

Architectural Contributions & Implementation

[01] PostGIS Spatial Database Design

Configured PostgreSQL with PostGIS geometry types and spatial indexing (GIST) to make boundary lookups and polygon intersection queries fast.

[02] File Upload & Conversion Pipeline

Built Node.js API endpoints to accept Shapefiles and GeoJSON data, validating coordinate projections before saving.

[03] Area Analysis Tools

Created API queries that calculate exact property square footage and check for boundary conflicts with nearby plots.

Delivered Artifacts & Results

• High-performance Node.js geospatial REST API
• Optimized PostGIS database schema with spatial indices
• Shapefile / GeoJSON upload and geometry normalization pipeline
• Area analysis endpoints for web-based GIS map visualization

About the Author: Kartik Butani is a Senior Software Engineer specializing in NestJS backends, React/Next.js platforms, and scalable data architectures. Explore more case studies at https://krbutani.in or connect on GitHub and LinkedIn.

GEAMS gives management a structured, two-tier review system to evaluate team performance and organize annual appraisals.

Overview

Conducting annual reviews across multiple company departments using email threads or paper forms was chaotic. Management wanted a transparent system where questions could be tailored by job role, and answers could be reviewed sequentially.

Engineering Challenges

• Handling different question sets for different job designations like operators, engineers, and production staff.
• Passing review forms between first-level and second-level managers in the right sequence without missing steps.
• Keeping all evaluation ratings and salary recommendations confidential until finalized.

Architectural Contributions & Implementation

[01] Question & Goal Management

Built admin screens where HR and executives can add review criteria, set question weights, and assign questionnaires by department.

[02] Multi-Level Approval Flow

Programmed the review pipeline so that once an employee submits their answers, notifications go to their direct manager, followed by division leadership.

[03] Exportable Reports

Added report generation to let management view score summaries and compare performance across departments.

Delivered Artifacts & Results

• GEAMS interactive administrative management portal
• Employee self-evaluation submission console
• Dual-level supervisor review and grading interface
• Automated score aggregation and salary recommendation engine

About the Author: Kartik Butani is a Senior Software Engineer specializing in NestJS backends, React/Next.js platforms, and scalable data architectures. Explore more case studies at https://krbutani.in or connect on GitHub and LinkedIn.

Indian Railway Telephony Directory gives staff and public users an easy way to locate railway officers across divisions.

Overview

With thousands of officers spread across Indian Railways zones and divisions, finding the right contact number used to mean searching thick printed telephone books. This mobile app put the directory right on officers' phones.

Engineering Challenges

• Keeping personal phone numbers restricted to authorized staff while keeping office landlines accessible to guests.
• Making contact lookups instantaneous even with thousands of officers across different zones.
• Ensuring officers could update their own details with verification.

Architectural Contributions & Implementation

[01] Role-Based Contact Visibility

Separated user access into three tiers (Apex, Non-Apex, Guest) so sensitive direct mobile numbers remain protected.

[02] Fast Search & Division Filters

Built search filters where users can quickly drill down by zone, division, department, or officer name.

[03] One-Touch Calling

Connected native phone dialer and email shortcuts directly from officer profile cards.

Delivered Artifacts & Results

• Production Flutter application published for Android
• Multi-tier security gate with SMS OTP validation
• Multi-parameter search and department filtering engine
• Profile self-service update module for railway officers

About the Author: Kartik Butani is a Senior Software Engineer specializing in NestJS backends, React/Next.js platforms, and scalable data architectures. Explore more case studies at https://krbutani.in or connect on GitHub and LinkedIn.

Jack Arrows delivers stock, index, and commodity trading calls directly to traders' phones the moment they are published.

Overview

In active trading, speed is everything. When market analysts identify a trade setup in Nifty or stock futures, subscribed traders need that alert on their screens immediately.

Engineering Challenges

• Ensuring push notifications wake up phones and show alerts with minimal delay.
• Gating premium trade recommendations behind subscription paywalls cleanly.
• Designing a clear dark interface where entry prices, stop-losses, and target prices are easy to read at a glance.

Architectural Contributions & Implementation

[01] Fast Notification Delivery

Connected Firebase Cloud Messaging with high priority so trade signals reach users without background delay.

[02] PayKun Gateway Setup

Integrated PayKun for smooth payment collection via UPI, debit cards, and net banking to activate paid plans.

[03] Clean Trading UI

Created a clean dark theme displaying buy/sell prices, target 1/2/3 levels, and stop loss points.

Delivered Artifacts & Results

• Jack Arrows Flutter mobile application for Android & iOS
• Live trade call feeds with Free and Paid tier access controls
• Instant FCM push alert receiver with foreground alert handling
• Integrated subscription purchase and receipt management

About the Author: Kartik Butani is a Senior Software Engineer specializing in NestJS backends, React/Next.js platforms, and scalable data architectures. Explore more case studies at https://krbutani.in or connect on GitHub and LinkedIn.

Amigose Overseas connects counselors and students with automated document workflows and real-time visa milestone tracking.

Overview

Consulting firms handle hundreds of active university applications at once across Canada, the UK, the US, and Australia. Using paper files or scattered spreadsheets led to missed deadlines and repetitive phone calls from anxious students. This unified platform gave counselors an organized pipeline and gave students transparent access to their application status.

Engineering Challenges

• Keeping track of different visa checklist requirements and university deadlines across multiple foreign countries.
• Providing students with an easy way to upload identity proofs and transcripts without losing track of versions.
• Giving agency management clear reporting on counselor conversion rates and pending applications.

Architectural Contributions & Implementation

[01] Counselor CRM Pipeline

Built the web administration portal where staff manage inquiries, record student scores (IELTS/PTE), and update application stages in real time.

[02] Document Verification Workflow

Programmed a structured checklist system where required student documents are verified, rejected with notes, or approved by senior counselors.

[03] Student Flutter Mobile App

Created the companion Android and iOS app so students can view their application timeline, receive offer letters, and view next steps directly.

[04] Instant Status Notifications

Integrated Firebase Cloud Messaging so students receive alerts the moment a university decision or visa update is logged.

Delivered Artifacts & Results

• Comprehensive web administration portal for counseling teams
• Student-facing Flutter mobile application
• Automated document checklist and verification engine
• Reporting dashboard for branch performance and visa approval rates

About the Author: Kartik Butani is a Senior Software Engineer specializing in NestJS backends, React/Next.js platforms, and scalable data architectures. Explore more case studies at https://krbutani.in or connect on GitHub and LinkedIn.