Rajeev Hansda

I'm a full-stack engineer with 3+ years of experience building real-time, multi-tenant systems for a global healthcare SaaS platform serving 30+ hospital clients across India, the Middle East, and Europe. At Teslon Technologies, I've worked across the entire stack — Node.js/Express on the backend, Vue.js and AngularJS on the frontend — architecting systems that handle live clinical workflows where reliability and low latency genuinely matter.

Some of the problems I've enjoyed solving most:

• Real-time infrastructure: Built a distributed WebSocket server (Socket.IO + Redis Pub/Sub) supporting ~500 concurrent connections per hospital, cutting patient-to-doctor communication latency by ~70% versus the old HTTP-polling approach.

• Distributed systems & concurrency: Designed a Redlock-based leader election and mutex-locking system to eliminate race conditions across 12+ concurrent Node.js processes — critical for things like invoice numbering and queue token generation in high-traffic OPD settings.

• Offline-first architecture: Built IndexedDB/Dexie.js-backed sync systems so field nurses and lab runners could keep working through unreliable hospital and rural connectivity, with zero data loss on reconnect.

• Healthcare interoperability: Integrated ABDM (India's national digital health mission) and built a pluggable FHIR R3/R4 EMR adapter pattern, cutting new hospital EMR integration time from 6+ weeks to under 2.

• Multi-tenant SaaS architecture: Designed white-labeling, SSO (SAML/OAuth2/OpenID Connect), and configuration-driven variant systems that let the same codebase power different hospital brands, insurance portals, and kiosk deployments without code forks.

I care about systems that stay reliable under real-world constraints — flaky networks, concurrent writes, multiple time zones, and non-technical end users (nurses, doctors, care coordinators) who need things to just work. I'm comfortable owning a feature end-to-end, from data model to UI to deployment (Docker, Jenkins CI/CD, multi-arch builds).

Outside of healthcare SaaS, I'm interested in real-time and IoT-adjacent systems more broadly — device streaming, MQTT, and edge/gateway architectures.

I'm based in Bengaluru, India, and open to remote roles with global teams.