Backend Architecture & API Design
Scalable microservices, REST/GraphQL APIs, versioning, secure contracts and API gateways.
Hi, I’m Harish Kumar — Backend Architect & AI Engineer
I design and build scalable web applications, resilient backends, and AI-driven systems for businesses worldwide — specializing in eCommerce, Finance, and Accounting.
- Experience
- 15+ years
- Domains
- Ecommerce • Finance • Accounting
- Stack
- Java • Go • PHP • Python • C# • NestJS
- Cloud & Infra
- AWS • Docker • K8s • CI/CD
About
As a seasoned Java Developer & AI Engineer, I specialize in building scalable web applications, intelligent backends, and modern AI-driven solutions. I have strong experience with Spring, Spring Boot, Play framework and enterprise databases (MySQL, SQL Server, PostgreSQL, MongoDB) plus caching and search with Redis and Elasticsearch.
I design and deploy LLM-powered solutions using ChatGPT, Claude, Gemini, DeepSeek and Grok — including fine-tuning, prompt engineering, RAG systems, and AI copilots integrated into enterprise workflows. I’ve delivered solutions across CMS, CRM, ERP, Accounting and Ecommerce platforms with integrations into QuickBooks, Xero, Sage, Salesforce, Zendesk, Shopify and WooCommerce.
Services
AI Engineering & RAG
LLM integration, retrieval-augmented generation, domain fine-tuning, and AI assistants for workflows.
Cloud Native & DevOps
CI/CD, Docker, Kubernetes, monitoring, cost optimization and secure deployments.
Database Design & Performance
Schema design, indexing, partitioning, caching strategies and OLAP/OLTP balancing.
Integration & Automation
Payment gateways, ERP/Accounting integrations, SaaS connectors, and automation scripts in Python/PHP.
Maintenance & Audits
Code audits, performance tuning, security reviews and test coverage improvements.
Tech Stack
- Java (Spring, Boot)
- Go
- PHP (Laravel)
- Python (Django)
- C# .NET
- NestJS
- Postgres • MySQL • MongoDB
- Redis • Elasticsearch
- Docker • K8s • AWS • Azure
Selected Projects & Impact
Representative examples — redact or replace these with real client/project names and metrics.
Enterprise Ecommerce Platform
Re-architected monolith into microservices; improved throughput by 3x and reduced checkout latency by 60%.
Financial Reporting & Reconciliation
Built reconciler and reporting engine integrated with QuickBooks and Xero, automating 80% of manual ledger work.
AI Copilot for Customer Support
Implemented RAG-based assistant that reduced first response times and deflected repetitive support tickets.
Accounting Automation for SMBs
Developed integrations with Sage and MyOB, automating invoicing and GST-compliant reports.
Contact & Hire
Share a brief of your project and timeline — I’ll respond with a suggested architecture, rough estimates, and next steps.
Or email me at honeyonsys@gmail.com