I'm a backend-first full stack engineer with 3+ years of experience designing and shipping production-grade, distributed systems. I specialize in event-driven architecture, serverless infrastructure, and high-throughput data pipelines β while retaining enough frontend depth to ship features end-to-end without handoffs.
I care deeply about system correctness under failure β idempotency, at-least-once delivery guarantees, race condition safety, and dead-letter queue handling are not afterthoughts in my systems; they're first-class design constraints.
βοΈ Architecture β Event-driven Β· Distributed Β· Serverless Β· Domain-Driven
π Philosophy β Design for failure first. Optimize for scale second.
π Currently β Owning backend systems & core business logic at duochat
π Open To β Backend / Full Stack roles in product-driven teams
- Architected multi-consumer Kafka pipelines with topic partitioning for parallelism, consumer group isolation, and lag monitoring
- Implemented at-least-once delivery with idempotency keys to prevent duplicate processing across retries
- Designed SQS FIFO queues for strict ordering with deduplication IDs and visibility timeouts tuned per job complexity
- Built SNS fan-out patterns for decoupled, multi-subscriber event broadcasting across service domains
- Applied dead-letter queue (DLQ) routing with CloudWatch alarms and automated replay strategies for failed events
- Implemented transactional outbox pattern to guarantee consistency between DB writes and event emissions
- Built Lambda-based async workflows triggered via SQS, SNS, and API Gateway with cold-start mitigation via provisioned concurrency
- Designed fully decoupled serverless pipelines for lead scoring, webhook ingestion, and scheduled report generation
- Used API Gateway + Lambda authorizers for custom JWT/token-based auth enforced at the edge
- Implemented S3 event-driven processing β file upload β SQS β Lambda β DB ingestion pipelines
- Configured CloudWatch dashboards & metric filters for real-time alerting on Lambda errors, DLQ depth, and P95 latency
- Managed infrastructure patterns across EC2, VPC, IAM roles/policies, and Secrets Manager
- Designed compound and partial indexes supporting high-cardinality filter queries with sub-10ms response times
- Built multi-stage aggregation pipelines (
$lookup,$unwind,$group,$facet) powering live analytics dashboards - Applied bucket pattern for time-series chat data to reduce document count and improve range query efficiency
- Implemented read preference tuning (secondary reads for analytics) to offload the primary and reduce hot-spot writes
- Used MongoDB change streams as lightweight event triggers for cache invalidation and downstream service sync
- Performed systematic query profiling via
explain()and slow query logs β achieving meaningful P95 latency reductions in production
- Designed WebSocket gateway in NestJS with room-based namespacing for multi-tenant chat isolation
- Built Kafka-backed fan-out β socket events emitted from a Kafka consumer, not the originating service, enabling horizontal scaling
- Implemented presence tracking with Redis TTL keys and heartbeat intervals for accurate agent online/offline state
- Handled socket reconnection logic with event buffering and replay windows to prevent message loss on disconnect
- Designed backpressure-aware consumers to throttle ingestion when downstream services are degraded
- Structured large NestJS codebases using modular DDD β domain-bounded modules, use-case interactors, and repository interfaces
- Applied CQRS pattern with command/query separation for write-heavy domains (chat assignment, analytics writes)
- Used custom interceptors for request logging, response serialization, and distributed tracing header propagation
- Implemented custom exception filters for structured error responses and Sentry/CloudWatch error forwarding
- Wrote unit + integration tests with Jest and Supertest β service logic fully isolated via mock repositories
- Enforced contract-first API design with Swagger decorators and class-validator DTOs with complete type safety
- Implemented exponential backoff + jitter on SQS/Kafka retry handlers to prevent thundering herd on cascading failure
- Designed circuit breaker wrappers (via
opossum) around third-party calls (Stripe, external APIs) with half-open probes - Applied optimistic locking on MongoDB documents for concurrent update conflicts (e.g., agent assignment races)
- Built idempotency middleware for webhooks and payment events β deduplication via Redis with configurable TTL windows
- Structured services for graceful shutdown β drain in-flight messages before SIGTERM completes in ECS/Kubernetes environments
- Maintained saga-style distributed transactions across services with compensating rollback actions on partial failure
Real-time communication & customer engagement platform. I own core backend systems and business logic powering live chat at scale.
| What I Built | Outcome |
|---|---|
| Event-driven chat infrastructure β Kafka consumers across assignment, notification & analytics domains | All domain concerns fully decoupled; horizontally scalable |
| Chat assignment engine β rule-based routing with race condition safety & SLA tracking | Zero double-assignments in production |
| Serverless automation β Lambda for lead scoring, webhook ingestion & scheduled reports | Eliminated all cron-based bottlenecks |
| MongoDB analytics pipelines β live dashboards with compound indexes & multi-stage aggregations | Significant P95 latency reduction on key queries |
| NestJS monolith decomposition β modular DDD refactor with clean domain boundaries | Reduced coupling; faster deploys and improved testability |
| WebSocket presence system β Redis-backed heartbeat + Kafka fan-out for real-time state | Accurate agent availability tracking at scale |
β
High-throughput event pipelines β Kafka, SQS, SNS, outbox pattern, fan-out
β
AWS serverless architectures β Lambda, API Gateway, S3 triggers, provisioned concurrency
β
MongoDB schema design at scale β Aggregations, indexing strategy, change streams
β
Resilient system design β DLQ, circuit breakers, idempotency, sagas, backpressure
β
Clean, modular NestJS codebases β CQRS, DDD, dependency injection, clean boundaries
β
Real-time systems β WebSockets, presence tracking, Kafka-backed fan-out
| Platform | Link |
|---|---|
| πΌ LinkedIn | arjun-patidar-6556b2226 |
| π§ Email | arjunjagotra2001@gmail.com |
| π GitHub | github.com/arjun808 |


