Bablu Kumar Singh
Backend-Focused Full Stack Developer
Backend Engineer specializing in Node.js, Express.js, MongoDB, PostgreSQL, Redis, RabbitMQ, AWS, Docker, Next.js, React.js, and React Native.
Bablu Kumar Singh
Backend & Full Stack Engineer
Noida, UP, India
Professional Summary
Highly motivated and results-driven Software Engineer with 1.5+ years of professional experience specializing in building production-ready web application backends and integrating full stack workflows. Proven success at designing multi-tenant SaaS dashboards, managing payment gateways, maintaining data integrity using relational and non-relational database indexes, and designing hierarchical permissions models.
Consistently translating complex business scenarios into high-performance web systems. Actively expanding backend discipline and data synchronisation principles into the cross-platform mobile domain using React Native and Expo.
Technical Skills
Categorised skills illustrating proficiency across frontend client development, backend engines, databases, cloud DevOps, messaging queues, and mobile architectures.
Frontend
Backend
Databases
Messaging
Cloud & DevOps
Mobile
Professional Experience
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.
Specialized Domains
A deep dive into how I implement high-availability backends, scalable client-server SaaS products, and performant offline-first mobile apps.
Backend Expertise
Focused on microservice architecture, API design, security, and high performance. Experienced in developing secure RESTful controllers, sanitizing request inputs, and configuring CORS parameters.
- •Database indexing & optimization for 30% reduction in query latencies.
- •Lightweight Redis caching & rate limiting policies protecting server threads.
- •Asynchronous broker routing with RabbitMQ pipelines handling background processing.
Full Stack Expertise
Bridging backend logical layers with clean browser layouts (using React and Next.js). Delivering optimized loading speeds, clean state management, and reliable customer billing workflows.
- •Multi-tenant SaaS dashboard (ROI Spectrum) separating database tenants cleanly.
- •Stripe integration with automated subscription billing and secure webhooks.
- •Zod schemas validating form payloads on client-side and endpoint interfaces.
Mobile Journey
Currently expanding core engineering skills into mobile application interfaces using React Native and the Expo ecosystem, emphasizing robust networking states and background synchronization.
- •Local database caching using SQLite inside React Native apps.
- •Offline-first replication patterns queueing server requests.
- •Push notification triggers utilizing Expo Client SDK.
Featured Projects
Practical demonstrations of complex permission models, subscription systems, and design patterns.
ROI Spectrum
SEO agencies and website owners lacked an integrated, multi-tenant solution to track ROI, audit logs, service tracking, and automated subscription billing transparently.
Forklift CRM
Operations managers struggled to handle lead assignments, track workflow automations, and manage sales representatives with clean role-based permissions.
Latest Articles
Technical summaries and walk-throughs concerning query optimizations, permissions configurations, and API controllers.
React Native Learning Journey: A Backend Developer's Perspective
A backend developer's honest journey into React Native with Expo — covering the mental model shift, navigation, state management, API integration, and how backend skills transfer to mobile development.
AWS for Backend Developers: Essential Services and Architecture Patterns
A backend developer's guide to essential AWS services — covering EC2, RDS, S3, SQS, CloudFront, and building a production-ready deployment architecture with Auto Scaling and load balancing.
Docker Deployment for Node.js Applications: A Production Guide
Learn how to containerize Node.js applications with multi-stage Docker builds, optimize image sizes, handle environment variables, and deploy with Docker Compose for development and production.
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.
Curriculum Vitae
Download complete professional timeline details in PDF format.
Let's build something scalable together
I am currently open to full-time Backend / Full Stack roles, contracting projects, and systems performance consultancies.