Bablu Kumar Singh
Full Stack Backend Developer
Full Stack Developer with 1.5+ years of experience building scalable SaaS platforms and backend systems using Node.js, Express.js, PostgreSQL, MongoDB, and Redis. Strong in backend architecture, API design, payment gateway integrations, RBAC, and multi-tenant systems. Proven ability to deliver high-performance, production-ready applications.
Development Philosophy
Code is for Humans
Write clean, readable, self-documenting code. Execution is for machines, but maintenance is for developers.
Fail-safe by Design
Build systems that handle errors gracefully. Implement boundary exceptions, retry queues, and robust validations.
Measure, Don't Guess
Never optimize blindly. Always run benchmarks, inspect EXPLAIN ANALYZE plans, and identify real query bottlenecks first.
Career Journey
Full Stack Developer @ X-Strategy Services LLP
Sept 2024 – Present- 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.
Daily DSA Journey
Consistently practicing Data Structures and Algorithms to reinforce algorithmic thinking, optimal time/space complexity analysis, and problem-solving speed.
Academic Foundations
Master of Computer Applications (MCA)
2022 – 2024A.N. College, Patna | 8.3 CGPA – Rank #1
B.Sc. Mathematics
2019 – 2022S.G.D.M. College, Patna
Current Learning Roadmap
System Design Patterns
Deep diving into Distributed Systems patterns: Eventual Consistency, CQRS, Saga Pattern, and CAP theorem trade-offs.
Mobile Apps (React Native)
Mastering the Expo ecosystem, local sqlite storage, navigation models, and offline-first client sync pipelines.
Rust & WebAssembly
Learning Rust memory models, ownership semantics, and writing blazingly fast WebAssembly backend workers.
Beyond the IDE
When I'm not writing APIs or fine-tuning database indexes, I enjoy resolving challenging chess positions, reading history, and discussing hardware scalability.