{S}~/shantanu
Available for work

Shantanu Bhusari

Backend engineer. I build distributed systems — microservices, event-driven pipelines, and real-time feeds that hold up in production.

Go · gRPC · AWS · Event-Driven Architecture

1
microservices shipped
across 2 platforms
1
Lambda functions
in production
1 yrs
professional
since 2023
// 01About

I'm a backend engineer who has designed and shipped production systems across e-commerce, fintech, and SaaS — 38+ microservices, 20+ Lambda functions, real users, real load. Most of the work is under NDA, but the architecture is mine to talk about.

I care about the decision behind the code. Why gRPC over REST for this service boundary. Why SQS is enough here and Kafka would be operational overhead. Why Fiber is the wrong framework inside a Lambda function — and how I learned that in production, diagnosed the cold start cost, and documented the fix. I try to know not just what to build but what not to reach for.

I'm open to backend engineering roles and contract work where architecture decisions actually matter — distributed systems, event-driven platforms, cloud-native infrastructure. If you're building at scale and want someone who has been there, let's talk.

Previously Leifii Media
// 02Skills
Backend
Primary stack across all production systems
Go
PythonPython
Node.jsNode.js
gRPC
WebSocket
Frameworks
Web frameworks used across production services
FastAPI
Express.js
Hono.js
Databases
MongoDB for flexible schemas · Redis sorted sets for O(log N) feeds
PostgreSQL
MongoDB
Redis
RabbitMQ
AWS
Serverless-first · Lambda + SQS across 3 platforms
AWS Lambda
AWS SQS
AWS SNS
AWS S3
AWS EC2
AWS ECS
AWS EventBridge
DevOps
Containerisation, IaC, and CI/CD pipelines
Docker
Terraform
GitHub Actions
Tools
Daily drivers for development
Claude Code
Cursor
Frontend
Next.js · supporting role in full-stack deliveries
Next.js
React
TypeScript
Currently Learning
Experimenting — not yet in production
Rust
Kotlin
Jetpack Compose
Kafka
ScyllaDB
Kubernetes
// 03How I Think
01

Requirements are constraints, not features

What does the user experience? What breaks if this is slow or down? That framing drives every decision — service boundaries, data model, failure modes.

02

Stack should fit where the product is

A monolith ships faster at phase one. gRPC and event-driven pipelines pay off at real scale — not before. I make the call that fits now, not what might be needed later.

03

Ship with measured confidence

Cloud services are decided before writing the first line. Production config comes from what testing actually showed — traffic patterns, latency, error rates — not guesses.

// 04Architecture

My Default Stack

asyncsyncClientMobile / WebHAProxyload balancingGo FibergRPC + RESTAWS SQSasync eventsMongoDB + Redispersistence + cacheLambdabackground workers

Production topology — 15-service grocery platform. gRPC for internal latency-sensitive calls; SQS for async event distribution; Lambda for compute-heavy background work.

// 05Projects
20 services · Lambda optimised

Lambda functions taking 6–9 seconds to cold start in production. Root cause: wrong framework for the runtime. Here's the diagnosis and the fix.

GogRPCAWS LambdaAWS SNSMongoDBRedisWebSocket
15 services · production

How do you keep product feeds consistent across 15 services without a distributed transaction? Event-driven with SQS, eventual consistency by design.

GogRPCAWS SQSMongoDBRedisDockerAWS Lambda
Go + Python · 4-service pipeline

Four-service platform: Go API gateway, Python AI worker, Go notification worker, Next.js client — each runtime owns the work it does best.

GoPythonAWS SQSRedisMongoDBNext.jsLangChainVector DB
CDC pattern · eventual consistency

Twitter-scale feed delivery at small scale: CDC pattern, Redis sorted sets for O(log N) retrieval, eventual consistency between writes and reads — by design.

GoPostgreSQLRedisRabbitMQWebSocketDocker
// 06Experience

Freelance Backend Engineer

Leifii MediaJan 2024 – Feb 2026 · Remote, India
  • Designed service communication strategy across two e-commerce platforms (15 and 20 services): gRPC for internal latency-sensitive calls, AWS SQS for async event distribution — chosen over Kafka for operational simplicity at this scale.
  • Diagnosed Lambda cold start bottleneck (6–9s) caused by Fiber framework overhead (5–10MB) and MongoDB init cost in FaaS context. Documented root cause analysis and migration path to minimal Lambda handlers.
  • Built event-driven order state machine: payment_confirmed → delivery_shipped → invoice_generation_queued — explicit event transitions rather than mutable status fields, enabling reliable async fan-out to notifications, inventory, and invoicing services.

Freelance Backend Engineer

Northen AgencyApr 2023 – Jun 2024 · Remote, India
  • Delivered 3 production SaaS backends (automotive, fitness, logistics) using Node.js, Express.js, MongoDB — monolithic architecture appropriate for project scale and timeline.
  • Built serverless logistics platform on AWS Lambda: sub-10s execution for trip tracking and billing. Single-function deployment pattern (Express wrapped in serverless-http) — later recognised as an anti-pattern and documented in subsequent Lambda work.

B.Tech — Electronics & Telecommunication

Vishwakarma Institute of TechnologyJan 2021 – May 2024 · Pune, India
  • Focus on distributed systems and algorithms
  • Built 10+ personal projects using JavaScript, TypeScript, Node.js, Express.js, and MongoDB
// 07Mini Experiments
Deep Dive

How to Build a 100k RPS View Counter: Cricket World Cup & IPL Scale

A deep-dive into engineering a high-throughput view counter in Go using Kafka, in-memory sharded aggregation, and slotted Postgres tables to handle 100,000 RPS.

GoGoKafkaKafkaPostgreSQLPostgreSQLRedisRedisDockerDocker
Deep DiveComing Soon

From Outage to Optimization: Stopping Cache Stampedes Dead in Their Tracks

How a thundering herd of cache misses can take down a production system — and the patterns (mutex locks, probabilistic early expiry, request coalescing) that stop them.

GoGoRedisRedis
// 08Contact

Let's build something together.

I'm open to full-time roles, freelance projects, and interesting collaborations. Reach out and let's talk.