Kunal Lingwal
Backend Developer
Building scalable backend systems, cloud infrastructure, and high-performance APIs.
I design and operate reliable distributed systems — from low-latency APIs and event pipelines to cloud infrastructure that ships with zero downtime. I care about correctness, observability, and the kind of performance that holds up under real production load.
- 99.9%
- Uptime
- 11K+
- Req / Day
- 40%
- Faster APIs
01 / About
Engineering for scale, reliability, and speed
I build backend systems where correctness and performance are first-class concerns — not afterthoughts.
I'm a backend developer focused on the parts of the stack that decide whether a product stays fast and trustworthy as it grows: API design, data modeling, caching, and the infrastructure underneath.
My work spans event-driven data pipelines, vectorized customer profiles, and zero-downtime deployments on AWS. I lean on observability — structured logs, Grafana dashboards, and quality gates — so regressions surface before users feel them.
Whether it's shaving p95 latency, hardening a release pipeline, or designing for graceful failure, I optimize for systems that behave predictably under real production load.
- 01
Backend Development
Idempotent, well-instrumented services in Node.js & Express that hold up under load.
- 02
System Design
Designing for failure first — clear boundaries, retries, and graceful degradation.
- 03
Cloud Architecture
AWS infrastructure with reverse proxies, TLS, and automated CI/CD pipelines.
- 04
Performance Optimization
Caching, indexing, and query tuning that measurably cut p95 latency.
- 05
Scalable Distributed Systems
Event-driven pipelines and vector data flows built to grow horizontally.
- 06
Observability & Quality
Structured logging, Grafana dashboards, and SonarQube gates baked into delivery.
02 / Experience
Where I've shipped
Backend and infrastructure work delivered in production, measured by the outcomes it produced.
Backend Developer
Datagen Pvt Ltd
Jul 2025 – Present
Kolkata, India
- Engineered a Customer Data Platform (CDP) pipeline ingesting user event data into MongoDB and vectorizing profiles with embeddings stored in Pinecone — enabling targeted campaign delivery, chatbot personalization, and workflow automation.
- Built automated Meta WhatsApp Business template submission workflows with approval polling and intelligent retry mechanisms.60% faster go-live
- Improved API performance through Redis caching, database indexing, and query optimization.40% lower p95 · 65% cache hit
- Provisioned AWS EC2 infrastructure with an Nginx reverse proxy, SSL/TLS configuration, and CI/CD pipelines enabling zero-downtime releases.40% faster deploys
- Built slot-based booking systems with RBAC and webhook integrations, plus real-time chat using Socket.io.35% faster resolution
Backend Developer Intern
Datagen Pvt Ltd
Nov 2024 – Jul 2025
Kolkata, India
- Developed scalable REST APIs using Node.js and Express.js with centralized logging and structured error handling.11K+ req/day · 99.9% uptime
- Built automated billing systems with idempotent APIs and retry mechanisms.5K+ txns/day · 40% fewer errors
- Developed an internal ticketing platform with SLA-based escalation workflows.25% faster MTTR · 30% productivity
03 / Skills
The stack I build on
Tools chosen for reliability and scale — grouped by where they sit in the system.
Backend
APIs & servicesDatabases
storage & vectorsCloud & DevOps
ship & scaleMonitoring & Quality
observe & gateInfrastructure
foundations04 / Impact
Outcomes, in numbers
Production metrics from systems I've designed, optimized, and operated.
Requests / Day
Transactions / Day
Uptime
Faster APIs
Faster Deployments
Cache Hit Ratio
Productivity Increase
05 / Contact
Let's build something reliable
Have a backend challenge, an infrastructure project, or a role in mind? I'd love to hear about it.
Get in touch
Based in Kolkata, India. Open to full-time, contract, and consulting opportunities.
Download Resume