Jatinjit Singh

Senior Full-Stack Engineer · Python · React / Next.js · AWS / GCPNagoya, Japan

Full-stack engineer with 8+ years shipping and operating production systems in Japan, specializing in Python backends (FastAPI, Django) with React/Next.js frontends. Built real-time streaming serving 5,000+ concurrent users, a multi-tenant SaaS platform end to end, and data pipelines behind consumer apps with 30,000+ registered users. Works both independently as a product owner and within cross-functional teams on monthly release cycles.

Experience

  • Designed and shipped Visa Cloud, a multi-tenant SaaS for Japanese immigration paperwork (COE, Change of Status, Renewal) — FastAPI/Django backend with tenant isolation and RBAC, an automated PDF-generation pipeline, and a React/Next.js frontend with complex multi-step forms. Deployed and operated end to end on AWS, cutting per-application processing from a full day of manual paperwork to under 30 minutes.
  • Architected Gayar's streaming infrastructure from scratch on SRS Server and Nginx RTMP, with a WebSocket layer synchronizing live commentary and audience participation across 5,000+ concurrent listeners per live event.
  • Owned the API layer, machine-performance data pipelines, real-time frontend visualizations, and push notifications across 5+ years of monthly releases — growing Stargroup to 10,000+ registered and 5,000+ weekly active users.
  • Built Protect, a family-safety iOS app integrating real-time GPS tracking, server-side Apple In-App Purchase validation, and an alert pipeline that contacts family members in parallel with emergency services — dispatching within seconds of a user trigger.
  • Migrated every environment to Terraform-managed IaC across AWS (EC2, S3, RDS, Lambda, SNS, CloudFront, VPC, IAM) and GCP (Cloud Run, Cloud SQL, GCS), wired into GitHub Actions CI/CD with CloudWatch and Sentry observability — cutting deployments and infrastructure debugging from full days to minutes.
  • Replaced a Dropbox-based file-sync pipeline with a self-hosted Syncthing instance in Docker, cutting sync failures from several per week to effectively zero and eliminating the recurring vendor cost entirely.
  • Maintained long-term ownership of Tamakoshi through 2024, delivering in-seat catering ordering, machine-performance graphs, and push notifications across 7+ years of monthly releases for a 30,000+ user platform.

Skills

  • Languages

    Python · TypeScript · JavaScript · Swift · Go

  • Frontend

    React · Next.js · Tanstack Starter Kit · HTML · CSS

  • Backend

    FastAPI · Django · REST · WebSockets · NestJS · GraphQL · PostgreSQL · MySQL · Redis

  • Cloud & Infra

    AWS · GCP · Terraform · Docker · GitHub Actions · Nginx · Syncthing · Caddy

  • Observability

    CloudWatch · Sentry

Projects