live backend runtime

Archishman Das

Senior Backend Engineer | Distributed Systems | Scalable APIs | Cloud-Native

4+ years in backend engineering. A system-focused engineer designing scalable backend platforms, tuning performance, and hardening reliability under real production load.

system.bootONLINE
>Initializing system...
users
10M+
apis
80+
latency
-40%

interactive architecture

System Design Visualization

A request path should feel coherent before it feels impressive. Hover a service to inspect its role. Click the canvas to replay the lifecycle.

live system topology

reading the system

Core services sit closest to the runtime center. Edge and infra layers stay wider, while async work moves on slower orbits to emphasize decoupling. Hover to inspect a service. Click anywhere to restart the request flow.

Core services
Async runtime
Infrastructure
Edge layer

experience stream

System Logs

[2022] Backend Foundation Built
-> Spring Boot service layers refactored for cleaner request paths
-> Response times improved by 20% through JPA query optimization
-> Core product revamp contributed to a 40% boost in user retention
[2025] Booking Engine Deployed
-> 1000+ concurrent users handled
-> Redis distributed locking implemented
-> Race conditions eliminated from allocation path
[2024] Microservices Migration
-> Service boundaries hardened
-> DB performance improved by 35%
-> CI/CD reliability upgraded
[2024] API Performance Pass
-> Latency reduced by 40%
-> Database load reduced by around 70%
-> Production monitoring loops tightened
[2023] Production API Surface Expanded
-> 80+ production-grade APIs shipped
-> Transactional contracts documented
-> Operational fixes delivered under pressure
incident report

Production Incident: Pricing Inconsistency

High-traffic transactional systems need one source of truth. This incident was contained by moving pricing correctness into deterministic backend validation.

status: resolved

Problem

Inconsistent pricing validation between standard and affiliate flows.

Root Cause

A validation gap existed between entry points before final transaction handling.

Solution

Deterministic backend validation made pricing rules authoritative server-side.

Impact

Prevented revenue leakage and stabilized trust in transactional pricing.

architecture decisions

Decision Records

Senior backend work is judgment under pressure. Pick a decision to inspect the constraint, tradeoff, and production impact behind it.

ADR-001: accepted
select record

active decision

Redis Locking Over Optimistic Guesswork

ADR-001 / accepted

Context

High-concurrency bookings were competing for the same inventory slot.

Decision

Guard the allocation path with Redis distributed locks and idempotency checks.

Tradeoff

Adds coordination overhead, but keeps correctness explicit under load.

Impact

Eliminated double-booking risk and protected 1000+ concurrent request flows.

philosophy

Engineering Principles

I don't just write code. I design systems that scale.

The point of principles is not purity. They help me keep systems legible, reduce failure surface area, and make change cheaper when the product inevitably shifts.

KISS

Keep It Simple, Stupid

If it needs explaining, it's already too complex.

I bias toward straightforward flows, obvious naming, and fewer moving parts so a teammate can debug production without a guided tour.

in practice

One clear service boundary beats three clever abstractions.

DRY

Don't Repeat Yourself

Duplication is a bug waiting to scale.

When the same rule shows up twice, I look for the missing contract. Shared logic belongs in one place with one owner.

in practice

Centralize pricing validation once, then make every entry point use it.

YAGNI

You Aren't Gonna Need It

Build for now. Not for imaginary futures.

I build for today's load, today's product, and today's constraints. Premature flexibility usually turns into permanent maintenance.

in practice

Ship the booking path first. Add the plugin system when a real second use case exists.

SOLID

Single Responsibility, Open/Closed, Liskov, Interface Segregation, Dependency Inversion

structured modules

Structure scales. Chaos doesn't.

Good structure keeps change local. The goal isn't ceremony, it's components and services that can evolve without collateral damage.

in practice

A card renders state. Data shapes live in lib. Motion stays at the edge.

system modules

Projects as Runtime Modules

Concurrent Booking Core

stable
Gateway->
Booking Engine->
Redis Lock->
Database->
Kafka Event

Problem

Peak demand caused competing writes for the same inventory slots.

Solution

A lock-first transactional path using Redis and idempotent booking commands.

Impact

100% slot allocation accuracy with 1000+ concurrent requests.

1000+ concurrency0 double-booking pathRedis lock guard

API Latency Reduction

optimized
Client->
API->
Cache->
Read Model->
Response

Problem

High-volume read paths amplified slow queries and downstream waits.

Solution

Query tuning, cache placement, and route-level response shaping.

Impact

40% lower API latency and around 70% less database load.

40% faster~70% DB reliefHot path cached

Reliability Pipeline

resilient
API->
Kafka->
Worker->
Monitor->
Rollback Guard

Problem

Background work leaked into synchronous request paths.

Solution

Kafka-backed async workers with retries, observability, and CI/CD gates.

Impact

Reliability improved by 25% with cleaner failure isolation.

25% reliability gainKafka asyncCI/CD guarded

mini game

Fix the Production Outage

incident deck: 40 scenarios
scenario #32

Log Volume Spike

Debug logs are saturating IO during peak traffic.

objective: Reduce noise before adding capacity.

incident scorecard

0

clean fix bonus: +75 | hint: -25 | crash: -50

solved

0

crashes

0

streak

0

best

0

hints used

0

latency

520ms

error rate

22%

throughput

365rps

runbook step 1/4: choose the safest next action

applied runbook

no actions applied yet

recruiter mode

Why hire me?

secure access terminal

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