Kartikey Sangal

Software Engineer

The Ladder AI • Full time

Jul 2025 - Present • 10 mos

Joined as the lead full-stack engineer responsible for building the core backend infrastructure for a Learning Management System (LMS) serving both web and mobile applications. I owned the backend architecture from the ground up — designing systems that could handle real scale while keeping query performance fast and infrastructure costs low. What I built: ✓ Scalable backend architecture using NestJS and Fastify, designed to support 5M+ active users ✓ Exam-level quiz modules with complex hierarchical learning structures (courses, modules, lessons, assessments) ✓ Optimized database queries and caching layers using PostgreSQL and Redis for sub-100ms response times ✓ RESTful API design serving both React web frontend and React Native mobile app ✓ Authentication and role-based access control using JWT and Passport.js ✓ Deployment pipelines with Docker and AWS Beyond engineering, I led client-facing technical strategy — conducting in-person and virtual meetings to align business requirements with technical architecture and manage sprint-level delivery timelines. Tech: NestJS, Fastify, Node.js, TypeScript, PostgreSQL, Redis, React, React Native, AWS, Docker, Prisma, JWT.

Software Engineer

hotinbox.ai • Full time

Sep 2025 - Jan 2026 • 4 mos

Working as a core engineer building the data infrastructure behind Hotinbox.ai — an outbound email automation platform that helps businesses reach their ideal customers at scale. My work focuses on building production-grade pipelines that automate the entire lead generation lifecycle — from raw data scraping to enriched, verified prospect lists ready for email campaigns. What I build and own: ✓ Automated data scraping pipelines that extract targeted prospect data from multiple sources ✓ Data enrichment systems that validate and enrich contact information (email verification, company matching, ICP filtering) ✓ Bulk processing workflows handling hundreds of thousands of records with error handling and retry logic ✓ API integrations connecting scraping tools, email verification services, and CRM platforms ✓ n8n automation workflows that orchestrate the full pipeline end-to-end without manual intervention Impact: Enabled clients to discover 11,000+ valid business contacts from Fortune 1000 companies through fully automated pipelines — saving thousands of dollars in manual prospecting work every month. Tech: Node.js, Python, n8n, REST APIs, PostgreSQL, data scraping, email verification APIs, webhook integrations.