Sankalp.
Full-Stack & Infra EngineerBuilding at scale
I’m passionate about architecting scalable, end-to-end systems with a focus on robust infra and system design. I thrive on exploring new technologies and contributing to open source.
A little about me
I'm Sankalp, a backend-heavy full-stack engineer focused on building performant, secure, and scalable systems. I bridge the gap between intuitive product experiences and the rock-solid reliability of secure, large-scale infrastructure.
Over the last few years, I've driven the evolution of the core platform at HackerRank, supporting 20M+ developers and $25M+ in ARR. My work has focused on owning and scaling mission-critical infrastructure, including cloud IDEs, code execution systems, and GenAI skill integrations, while balancing reliability with insanely great developer experience.
I'm passionate about building reliable, scalable backend systems with clear intent focusing on why we're building something, not just how to deliver it. I bring this mindset to open source as well, contributing to projects and mentoring across communities in organizations like OpenWISP.
Technical Skills
I'm always exploring new skills and the latest technologies. Below are some of the areas and tools I've worked with in the past:
Languages
Python, Ruby, Go, TypeScript, JavaScript, SQL
Runtimes & Platforms
Linux, Node.js, OpenWRT
Infrastructure & Cloud
Kubernetes, AWS, GCP, Azure, Terraform, Docker, Runc, Helm, KEDA, CI/CD
Distributed Systems
Kafka, BigTable, Cassandra, MySQL, PostgreSQL, Redis, Elasticsearch
Frameworks
Django, Flask, Ruby on Rails, Express.js, React.js, Next.js
Observability
Prometheus, Grafana, Logstash, Kibana
Full activity timeline is also reflected in my WakaTime profile
Where I've worked & contributed
Built and scaled core assessment infrastructure across workspace provisioning, code execution system, runtime platform, reliability engineering, and multi-cloud readiness for large-scale enterprise hiring events and day-to-day developer assessments.
- Architected secure LLM assessment platform with RAG and custom proxy controls (TPM/RPM), helping evaluate 20M+ AI developer candidates and supporting $1M+ ARR outcomes.
- Reduced cloud IDE provisioning time by 92% (45s to 3.6s), enabled 10+ enterprise client expansions, and sustained 1,000 provisions/min in multi-region deployments.
- Scaled distributed CodeRunner systems from 50K to 200K concurrent users; eliminated filestore bottlenecks via runc-bundle architecture and prevented $50K+ infra overprovisioning.
- Built traffic-driven predictive autoscaling with 48-hour forecasting; maintained 99.9% uptime during 10x spikes while reducing cloud spend by 35% across AWS/GCP.
- Owned multilingual data science platform improvements (Python/R/Julia JupyterLab provisioning), contributing to $800K in new bookings.
- Reduced annual infrastructure cost by $30K through service optimization and automated cleanup of long-running workspaces.
- Implemented Docker layer switching with secondary-disk dependency warmups and fallback install paths for resilient, low-latency workspace provisioning.
- Optimized Golang workspace services and parallelized Ruby on Rails orchestrator flows, improving deployment velocity by 40% and reducing P95 latency from 8s to 2.1s.
- Drove quota/API/worker improvements: bulk VM creation, Redis pipelines, connection pooling, batched DB updates, and high-throughput load testing.
- Led VM provider modernization and failover readiness across AWS and GCP; delivered production-safe proxy rollout and infra automation with Terraform/Packer.
- Authored API-first integration guides and led cross-team workshops to accelerate product onboarding onto shared skills/workspace infrastructure.
- Mentored 2 engineers in team, conducted 30+ technical interviews, and drove architecture reviews for 12+ infrastructure initiatives.
- Recognized as a 7-time Kudos award winner for exceptional technical contributions and strong customer focus.
Started as a GSoC student and grew into long-term core contributions across OpenWISP services, owning reliability, developer experience, and performance improvements across the ecosystem.
- Contributed broadly across OpenWISP repos/services including openwisp-wifi-login-pages, openwisp-controller, openwisp-radius, openwisp-users, openwisp-notifications, openwisp-ipam, openwisp-firmware-upgrader, docker-openwisp, and NetJSONGraph.js.
- Optimized NetJSONGraph.js and WLP bundle size for faster load times and better frontend performance.
- Delivered production-focused fixes across captive portal login/registration, controller/runtime behavior, dependency upgrades, CI/test pipelines, and docs/devex improvements.
- Built the OpenWISP downloads workflow used to browse and distribute package artifacts (for example, openwisp-config releases).
Built data platform services for real-time analytics pipelines with a focus on throughput, reliability, and cost-efficient autoscaling.
- Built data pipelines with Apache Beam and Pub/Sub, achieving 10K+ messages/sec throughput into BigTable for real-time analytics workloads in Python.
- Implemented a data fetcher service with autoscaling, auto-retry logic, and dead-letter queues, improving ingestion reliability from 92% to 99.7%.
- Implemented autoscaling for Django Celery workers using KEDA, reducing infrastructure costs by 50% while maintaining system reliability.
Snapy
Full Stack Developer
Remote · Bengaluru, India
Worked across frontend, backend, and ML serving workflows to deliver product features quickly during the internship.
- Developed responsive and user-friendly interfaces using React and Tailwind CSS, improving overall product UX.
- Built 100+ REST APIs with advanced backend features in Django, focusing on efficient response times and reliable service behavior.
- Deployed multiple machine learning models on Flask servers, gaining hands-on MLOps deployment experience.
- Collaborated closely with Kailash Ahirwal to adopt new technologies and engineering best practices in day-to-day delivery.
From the blog
Let's work together
Whether you're working on something interesting, looking to collaborate on open source, or just want to talk engineering - my inbox is always open. I'm especially interested in open-source collaboration and tough technical challenges.
Say hello