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Sandip Bera

Backend Application Developer | Golang & Distributed Systems

📍 Kolkata, India (Open to Remote / Relocation)•+91 8918533450•sandipbera35@outlook.com•linkedin.com/in/sandipbera•github.com/sandipbera35•sandipbera.in
Total Experience: 4+ Years (4 Yrs 1 Mo)Notice Period: Immediate to 30 DaysMCA CGPA: 9.64 / 10

Professional Summary

Backend Engineer with 4+ years of hands-on experience architecting and delivering high-throughput REST APIs, event-driven microservices, and distributed systems using Golang and Node.js. Specialized in Go concurrency (goroutines, channels, WaitGroup, bounded semaphores), distributed messaging (RabbitMQ, Kafka), database schema tuning (PostgreSQL, MySQL, Redis), and cloud storage (MinIO). Proven track record delivering 16+ production backend services including a Netflix-like OTT platform, asynchronous video transcoding (~4x speedup), real-time chat, and production RAG AI pipelines (OpenAI API, pgvector, LangChainGo, Model Context Protocol).

Technical Skills

Languages: Golang, Node.js, TypeScript, JavaScript, SQL, Python (Basic), Java (Basic)
Go Ecosystem: Go Iris, Go Fiber, GORM, Goroutines, Channels, WaitGroup, Semaphores
Distributed & Messaging: RabbitMQ (Topic/Worker Queues, DLQ), Apache Kafka, WebSockets, Socket.IO
Databases & Storage: PostgreSQL, Redis (Pub/Sub, Caching), MySQL, pgvector, MinIO (S3)
AI & Modern Tooling: RAG Pipelines, OpenAI API, LangChainGo, MCP (Model Context Protocol), FFmpeg
Security & DevOps: OAuth2, RS256 JWT, RBAC, Docker, Git, GitHub Actions, Postman, Linux

Work Experience

Backend Application Developer — DigiAir Technology and Analytics Pvt. Ltd.

08/2022 - Present | Kolkata, West Bengal, India
  • Delivered 16+ production backend services and internal tools across Golang and Node.js covering high-scale microservices, database architecture, and Redis caching.
  • Architected backend modules for a Netflix-like OTT streaming platform (Go, Iris, GORM, PostgreSQL, RabbitMQ, MinIO) managing title catalogs, channels, media resolutions, and administrative access-control workflows.
  • Reduced multi-resolution video transcoding processing time by ~4x via an asynchronous Go service using goroutines, sync.WaitGroup, and a 6-way concurrency semaphore around FFmpeg.
  • Implemented high-security OAuth2 authentication with RS256 JWT tokens using RSA private keys, HttpOnly storage, and granular RBAC, cutting security incidents by 30%.
  • Developed a real-time chat backend (Node.js, Express, Socket.IO, Redis) with private & group chats, file streaming, and RabbitMQ message queue delivery for zero message loss.
  • Decoupled Meet and Calendar microservices using RabbitMQ message broker for asynchronous event-driven integration, guaranteeing at-least-once delivery and high system resilience.
  • Spearheaded internal AI initiatives integrating OpenAI API: deployed a high-precision RAG PDF Q&A pipeline with pgvector & LangChainGo, and a content-moderation microservice for sensitive uploads.
  • Optimized relational database queries (PostgreSQL/MySQL) by 25% and implemented MinIO object storage, reducing cloud storage infrastructure costs by 20%.
  • Achieved 98%+ bug-free delivery across releases by enforcing robust automated testing workflows and end-to-end Postman API suites.

Key Architecture & Engineering Projects

OTT Platform Backend (Golang, Go Iris, PostgreSQL, GORM, RabbitMQ)
Production System
  • Architected scalable backend microservices for an OTT platform handling content catalogs, channel management, video resolutions, comments, reactions, notifications, and administrative workflows.
  • Engineered zero-trust OAuth2 and RS256 JWT authentication with token expiry windows and role-based access control (RBAC) across channels and paid tiers.
  • Reduced security-related incidents by 30% through reinforced access-control policies.
Video Processing Service (Golang, FFmpeg, Goroutines, sync.WaitGroup, 6-Way Semaphore)
4x Acceleration
  • Implemented an asynchronous Go service that transcodes videos into multiple resolutions in parallel using FFmpeg and concurrent goroutines.
  • Used WaitGroup for synchronization and a 6-way semaphore to cap concurrency, achieving up to 4x reduction in processing time versus sequential transcodes.
  • Published results via RabbitMQ and stored outputs in MinIO for efficient retrieval.
Real-Time Chat Backend (Node.js, Express.js, Socket.IO, Redis, RabbitMQ)
Low-Latency Real-Time
  • Built a chat backend supporting private and group chat, file upload/streaming, bookmarks, search and message forwarding.
  • Implemented Socket.IO real-time delivery with socket-to-queue messaging via RabbitMQ, Redis caching and JWT-based profile checks.
Meet–Calendar Event Sync (Golang, RabbitMQ, Microservices, Event-Driven Architecture)
Event-Driven
  • Engineered a decoupled event-driven integration between Meet and Calendar microservices.
  • Utilized RabbitMQ to publish events asynchronously ensuring at-least-once delivery and improved system scalability.
RAG backend (PDF Knowledge Engine) (Golang, OpenAI API, pgvector, LangChainGo, PostgreSQL)
Generative AI
  • Developed a Retrieval-Augmented Generation pipeline to ingest large PDFs and answer queries using OpenAI API, pgvector and LangChainGo.
  • Improved high-precision ingestion and retrieval to support internal PDF Q&A functionality.
Content moderation microservice (Golang, OpenAI API, LangChainGo, pgvector, Microservices)
AI Compliance
  • Built a microservice to filter sensitive images and documents using OpenAI API and LangChainGo.
  • Implemented pgvector to assist image search and moderation against blacklisted content.

Education

Master of Computer Applications (MCA)
Netaji Subhas Engineering College (08/2020 - 06/2022)
9.64 / 10 CGPA (Top-Tier Academic Distinction)
Bachelor of Computer Applications (BCA)
Vidyasagar University, Belda College (08/2017 - 06/2020)
First Class
Higher Secondary (12th Standard - Science)
West Bengal Council of Higher Secondary Education (2017)
70%

Certifications & Leadership

  • Building Modern Web Applications with Go (Golang) — Udemy
  • SQL (Intermediate) — HackerRank / Simplilearn
  • Guided Pentest: Infrastructure — TryHackMe / PentesterLab
  • Academic Project Leadership: Led a 3-member engineering team developing an ML Network Intrusion Detection model (KDDCUP99).
  • Languages: English (Professional), Bengali (Native), Hindi (Professional)