Available for freelance & collaboration

I build scalable backends & write content that ranks.

Backend developer and technical writer helping companies ship reliable systems and publish content that drives organic growth.

3+
Years Experience
50+
Articles Published
96%
Client Satisfaction

Engineer by trade.
Writer by craft.

I'm Kunal Kejriwal — a backend engineer specializing in building high-throughput, distributed systems using Python (Django, FastAPI, DRF) and cloud-native architectures.

At Deloitte, I architected asynchronous data pipelines processing 20M+ records/day, built enterprise-grade search infrastructure on GCP, and improved API performance by 35% through deep backend optimizations. I work extensively with event-driven systems, Celery-based task orchestration, and scalable REST APIs designed for real-world production loads.

I operate at the intersection of building and explaining — designing systems that perform under pressure, and writing content that makes complex technology accessible and discoverable.

Technical toolkit

Primary Stack

PythonDjangoDjango REST FrameworkFastAPIREST API Designasyncio

Systems & Infrastructure

CeleryRedisKafkaGCP Pub/SubWebSocketsDockerGCPCloud RunPostgreSQLSQLAlchemy

Secondary / Polyglot

JavaSpring BootNode.jsJavaScriptSQLHibernate

Practices

MicroservicesSystem DesignEvent-Driven ArchitecturePerformance EngineeringCI/CDpytestAgile

Projects that shipped

APIEngine

Developer Tools / SaaS
PythonDjangoDRFFastAPIRedisCeleryPostgreSQLDockerGCP
Problem

Mock APIs and localhost servers don't behave like production systems — no real validation, no persistence, no network behavior. Integration issues surface late in development when changes are costly.

Solution

Built a schema-driven live backend simulation platform with a custom URL dispatcher and request multiplexer. Developers define JSON Schema Objects and instantly get globally accessible REST endpoints with real persistence, per-user namespace isolation, configurable rate limits, and full CRUD. Background jobs run via Celery + Redis with retry logic and dead-letter queues; deployed on GCP.

Custom URL dispatcher with per-user namespace isolation
Celery + Redis background jobs with retry logic and dead-letter queues
Full CRUD with filtering, sorting, and pagination out of the box
Configurable rate limits and extensible schema support
Impact

Supports 500+ Developers, 250K+ API calls/user/month.

View Project

MeshEngine

Systems / Infrastructure
PythonFastAPIPostgreSQLRedis Pub/SubSQLAlchemyWebSocketsDockerGCP
Problem

Distributed systems research and defence/disaster-recovery planning require testing self-healing drone mesh networks, but existing tools are either too RF-specific or too general — no async event model, no HTTP interface, no real failure simulation.

Solution

Built a backend simulation platform with a control-plane/worker-plane split: FastAPI control plane handles topology and failure-aware Dijkstra routing [O((V+E) log V)], while independent async workers subscribe to Redis Pub/Sub events for fan-out execution. Chose Redis Pub/Sub over Kafka for lower operational overhead given PostgreSQL-backed persistence. Deployed on GCP Cloud Run with Cloud SQL and Memorystore.

Failure-aware Dijkstra — DOWN nodes pruned before traversal, O((V+E) log V)
Redis Pub/Sub fan-out across independent async worker plane
structlog + per-message latency breakdown + GCP Cloud Monitoring uptime checks
WebSocket /ws/stream for live topology events
Impact

End-to-end simulation of self-healing mesh networks: real-time failure/recovery events, multi-hop Dijkstra routing, per-message hop-by-hop latency breakdown, and live WebSocket event stream. 25 automated tests (unit + topology).

View Project

Where I've worked

Deloitte USI
Oct 2023 – Present
Gurugram, India
Associate Engineer — Backend

Backend engineer on ChangeScout — an enterprise OCM platform serving 150+ global clients within a 40-person eng/PM/QA team.

Async Pipeline Ownership: Architected high-throughput async pipelines processing 20M+ records/day (load-tested to ~30M), orchestrating Celery workers with Redis-backed task queues under strict API rate limits. Selected Cloud Run over GKE for stateless workloads to minimize operational overhead while retaining auto-scaling.
Latency Optimization: Cut API response time by 35% by eliminating N+1 query patterns (batched prefetch joins), refactoring O(n²) list-intersection logic to O(n) hash-set lookups, and compressing response payloads across critical endpoints.
Enterprise Search (GCP): Built and owned an end-to-end search feature — integrated GCP Search with a Java/Spring Boot service layer, indexed 50K+ documents in Cloud Storage, and served ranked results via a low-latency REST API (p95 < 200ms).
Observability & Logging: Designed a centralized error-logging system for all REST API failures with structured logs, request context, stack traces, and severity tagging. Built role-based access (admin-only) with indexed lookup by timestamp and endpoint.
CI/CD & Cloud Ops: Architected deployment pipelines (GitHub Actions + GCP Cloud Build) enabling zero-downtime containerized releases on Cloud Run with automated rollback.
Oct 2023 – Present
Remote
Technical Writer — AI/ML

Contributing writer covering cutting-edge AI/ML research for a global developer and research audience.

Authored 100+ in-depth technical articles on LLMs, multimodal models, diffusion models, model optimization (MoE, PEFT), and AI infrastructure.
Topics span from foundational research to applied systems: vision-language models, efficient inference, world models, AutoML, and Vertex AI.
Content reaches a global developer and research audience — consistently translating dense academic papers into clear, actionable technical writing.
DeepVision
Jan 2023 – Jun 2023
Remote
Project Intern — Backend

Backend internship focused on productionizing computer vision model inference.

Built production REST APIs in Python serving computer vision model inference on image and video input.
Implemented structured error handling, input validation, and latency monitoring across inference endpoints.

Trusted by engineers and AI leaders

Across distributed systems, backend engineering, and AI/ML communication

Backend Engineering · Deloitte
Backend Engineering

Kunal stood out as a strong backend engineer with a sharp eye for performance. He built high-throughput APIs and data pipelines at scale — consistently focused on reliability and optimization. Proactive, collaborative, and takes full ownership.

Vamsi Battula
Software Engineer, Deloitte
Backend Engineering

Kunal brings a genuine problem-solving mindset to complex backend challenges. What stood out most was his ability to bridge development and QA — resolving critical issues during SIT cycles with clarity and ownership.

Kiran
QA Engineer, Deloitte
Backend Engineering

Reliable, skilled, and always willing to step up. Kunal has a strong grasp of backend fundamentals and delivers high-quality work with real ownership — consistently.

Swati
Software Engineer, Deloitte
AI & Technical Writing · Unite.AI
AI & Technical Writing

Kunal translates complex AI topics — agents, multimodal systems, modern ML — into content that resonates with both technical and broader audiences. He brings a thoughtful, analytical approach that's rare in the AI writing space.

Antoine Tardiff
Forbes Business Council

Looking to build scalable backends or high-quality technical content?

Whether you need a robust API platform, a full-stack backend system, or SEO-optimized developer content — let's talk.

Get in touch

Have a project in mind or want to discuss a collaboration? Drop me a message — I typically respond within 24 hours.