Hi, I'm Bablu Kumar Singh
A backend-focused Full Stack Developer and Software Engineer. I design secure API microservices, optimize database queries, implement multi-tenant SaaS logic, and build performance-first systems that scale seamlessly.
Bablu Kumar Singh
Software Engineer
Noida, UP, India
Technical Expertise
Broad architectural understanding, with deep specialized knowledge in databases, API performance, and security.
Backend Engineering
- Node.js
- Express.js
- REST APIs
- GraphQL
- Microservices
- RBAC Security
Databases & Cache
- PostgreSQL
- MongoDB
- Redis Caching
- Mongoose
- SQL Query Tuning
- ACID Transactions
DevOps & Infrastructure
- AWS (EC2, S3)
- Docker
- Nginx Reverse Proxy
- RabbitMQ Message Broker
- CI/CD Pipelines
Frontend & Mobile
- React.js
- Next.js
- TypeScript
- Tailwind CSS
- React Native
- Expo Ecosystem
System Architecture Visualizer
Explore how an enterprise request navigates through my typical backend infrastructure setup, with full event tracing.
SSL Termination, CORS headers, reverse proxy routing.
IP rate limiting & sanitization checks.
Token validation & role-based validation.
In-memory fast lookup to bypass DB load.
Business logic execution & data transformations.
Asynchronous event worker message queueing.
Write operation with ACID transaction guarantees.
Production Showcases
Explore backend architecture blueprints, database design diagrams, and result metrics for key projects.
ROI Spectrum
Challenge / Context
SEO agencies and website owners lacked an integrated, multi-tenant solution to track ROI, audit logs, service tracking, and automated subscription billing transparently.
System Architecture
Multi-tenant database schema architecture using Node.js/Express backend, React.js frontend, and hybrid storage using PostgreSQL for relational billing data and MongoDB for audit logs.
Results & Accomplishments
Successfully deployed and launched the platform at roispectrum.com, handling hundreds of active tenants, reducing query response times by 30% through composite indexing, and fully automating subscription operations.
Technologies Used
Professional Timeline
Professional history showing growth, architectural design responsibility, and system deployment.
Full Stack Developer
- Took end-to-end ownership of application development across backend systems and frontend interfaces, ensuring scalable architecture and timely delivery.
- Architected and developed ROI Spectrum, a multi-tenant SaaS platform with subscription workflows, service tracking, audit logs, and user-facing dashboards.
- Implemented payment gateway integrations with subscription lifecycle handling, webhook automation, and billing workflows.
- Designed and delivered 200+ RESTful APIs with validation, versioning, and error handling across production systems.
- Optimized APIs and database queries using indexing and aggregation strategies, reducing response time by 30%.
- Implemented role-based access control (RBAC) systems with hierarchical permissions across multiple user roles.
Academic Foundation
A.N. College, Patna
Rank #1 • 8.3 CGPA
Rigorous advanced focus on algorithms, relational database administration, compiler design, software testing, and network security protocol layers.
S.G.D.M. College, Patna
Mathematics Honours
Strong grounding in discrete mathematics, numerical analysis, abstract algebra, statistics, and logical systems helpful for complexity analysis.
Frequently Asked Questions
Find quick, search-indexed answers regarding my experience, methodologies, and technical stack.
Let's build something scalable together
I am currently open to full-time Backend / Full Stack roles, contracting projects, and systems performance consultancies.