Skills Work Contact

Backend Developer · Cloud Engineer

Suraj
Kumar

Software Developer & Proprietor · Crystal Software

I build backend systems and cloud infrastructure that hold up under real load. Specializing in scalable architecture, server operations, and business automation — from Java APIs to production email servers.

sk-profile.json · running
name "Suraj Kumar"
company "Crystal Software"
role "Proprietor & Dev"
stack ["Java", "Spring", "AWS"]
status online
open_to_work true

Technical Stack

What I Work With

Backend systems, cloud infrastructure, and the glue that connects them — built to stay running.

Backend & Languages

Java Spring Boot Python REST APIs Middleware

Cloud & Infrastructure

AWS EC2 Contabo VPS Ubuntu Server Linux Admin

Tools & Services

Mailcow aaPanel DNS Management Tally Integration

Work & Projects

Experience

Real problems solved in production — from business software to infrastructure that doesn't need babysitting.

Role Crystal Software · Ongoing

Proprietor & Lead Developer

Run Crystal Software end-to-end — setting technical direction, designing accounting solutions for SMBs, and building the web infrastructure those products run on. Every architecture decision lands on my desk, and so does every deployment.

Architecture Accounting Systems Team Leadership
Project Crystal Software

Amazon → Tally Sales Automation

Built a Spring Boot middleware service that pulls live sales data from the Amazon SP-API and syncs it directly into Tally, replacing a daily manual export-import cycle. Cut reconciliation time for clients from hours to minutes, with zero data entry.

Java Spring Boot Amazon SP-API Tally Integration Middleware
Project Crystal Software

Production Email & Cloud Infrastructure

Configured and deployed self-hosted email servers using Mailcow on Ubuntu, running across Contabo VPS and AWS EC2 instances. Handled full DNS setup — SPF, DKIM, DMARC — SSL termination, and aaPanel environments. Zero downtime since go-live.

Mailcow Ubuntu Server AWS EC2 Contabo VPS DNS / SSL aaPanel

Get In Touch

Let's Work Together

Whether you need backend engineering, cloud setup, or a Tally integration that actually works — send me a message and I'll get back to you within a day.