Libin P R

Software Engineer (Backend) — Node.js · Spring Boot · PostgreSQL · RabbitMQ · AWS · MySQL

Backend engineer with 1+ year of experience building REST APIs, payment integrations, authentication systems, caching layers, and AWS-hosted services using Node.js and Spring Boot. Passionate about scalable backend architecture, system design, and performance optimization.

View projects Download resume

github.com/LibinPR · linkedin.com/in/libin-p-r

01 · dependencies

What I build with

Languages

JavaTypeScriptJavaScript

Backend

Node.js Spring Boot

Databases

PostgreSQLMySQLRedispgvector

Cloud

AWS EC2S3CloudFrontIAM

Tools

PrismaHibernateDockerPostmanGit

Concepts

REST APIsJWT / RBACCachingRAG / LLMDistributed SystemsSystem Design

02 · runtime log

Experience

Backend Engineer

Venturebiz Promotions Pvt. Ltd. — Offerbeez (hyperlocal eCommerce platform)

● active May 2025 — Present Bengaluru, India

Built and maintained 50+ REST APIs supporting Admin, Business, Sales and User workflows including onboarding, subscriptions, payments and notifications.
Implemented JWT authentication and RBAC across all roles, securing APIs against unauthorized access.
Optimized PostgreSQL queries using composite indexes and normalized relationships, improving latency on high traffic endpoints by an estimated 35–40%.
Integrated Razorpay, CCAvenue, Google Maps API and SMS OTP services, implementing idempotent payment processing to safely handle webhook retries and prevent duplicate transaction updates.
Designed and deployed a Spring Boot Banner Management microservice integrated with the Node.js backend through REST APIs, allowing independent deployments.
Deployed and maintained services on AWS EC2, S3 and CloudFront, improving media delivery performance and reducing origin load.
Structured the backend using layered architecture for improved maintainability and easier onboarding.
Diagnosed and resolved production issues across APIs, integrations and database workflows to improve reliability.

03 · deployed services

Projects

EVENT /projects/notix 202 Accepted

Notix

An event-driven notification platform built around asynchronous messaging with RabbitMQ, focusing on reliable delivery, fault tolerance, and safe event processing.

Built an event-driven notification platform using RabbitMQ for asynchronous communication between services.
Implemented idempotent consumers, retry mechanisms, and Dead Letter Queue (DLQ) handling to safely process duplicate and failed events.
Applied the Outbox Pattern to guarantee reliable event publishing between transactional database operations and asynchronous consumers.
Designed the platform around eventual consistency, fault tolerance and reliable message delivery.

RabbitMQEvent-DrivenOutbox PatternDLQ

GET /projects/url-shortener 200 OK

URL Shortener

A scalable URL shortening service designed for high-read traffic. Redis cache-aside serves hot redirects with very low latency while PostgreSQL remains the system of record.

PostgreSQL schema with partial indexes on active URLs only — lower index bloat, faster lookups on the critical redirect path.
Custom aliases, TTL-based expiry, soft deletion, and per-URL click analytics.
Documented trade-offs: cache-aside vs write-through, partial vs full indexes.

Node.jsPostgreSQLRedisCache-Aside

GET /projects/ai-knowledge-assistant 200 OK

AI Knowledge Assistant (RAG System)

A Spring Boot service implementing Retrieval-Augmented Generation with semantic search over PDF, DOCX, TXT, and Markdown documents — using pgvector and a Groq LLM.

Vector embeddings and cosine similarity search via pgvector for document retrieval.
Secure auth with JWT, refresh tokens, and role-based access control.
Containerized with Docker; ingestion and query pipelines independently deployable and testable.

Spring BootPostgreSQLpgvectorLLM

04 · build origin

Education

B.E. in Computer Science

S.E.A College of Engineering & Technology, Bengaluru

CGPA : 7.98 / 10

05 · credentials

Certifications

Java Full Stack Developer

Kodnest

AWS Certified Developer

Planned

06 · architecture

System Design

Cache Aside Idempotency Outbox Pattern DLQ Distributed Locks Retry Strategies Eventual Consistency Read Replicas Backpressure Optimistic Locking