Hello, I’m Kejian Tong

Software engineer crafting scalable services and memorable product experiences.

I’m a Software Engineer specializing in backend architecture, distributed systems, and microservice-based application design. I focus on building scalable, reliable, and high-performance platforms that power modern enterprise workflows and data-driven services.

  • Core Focus

    Distributed systems

    Event-driven, resilient services

  • Toolbox

    Java · TypeScript · Python · Cloud

    Docker · Kubernetes · Microservices

  • Community

    Mentor & collaborator

    Always shipping with teammates

Highlights

  • Distributed systems & cloud architecture
  • Backend engineering with Java, Go, Python, and Node.js
  • Full‑stack delivery with React, Next.js, and TypeScript

About

Engineer focused on scalable, reliable systems.

I’m a Software Engineer specializing in backend architecture, distributed systems, and microservice-based application design. I focus on building scalable, reliable, and high-performance platforms that power modern enterprise workflows and data-driven services.

In recent projects, I’ve designed and optimized distributed microservices with Kafka, Redis, and RESTful APIs, enabling asynchronous communication and real-time data processing at scale. I’ve also containerized and deployed applications using Docker and CI/CD pipelines, ensuring efficient delivery and consistent system behavior across multiple environments.

My work emphasizes system scalability, fault tolerance, and performance optimization—from designing event-driven pipelines to fine-tuning database queries for high-concurrency workloads. I value clean architecture, well-documented APIs, and automation that drives engineering efficiency.

Technical Focus

  • Java
  • Go
  • Python
  • TypeScript
  • Node.js
  • React
  • Redis
  • Kafka
  • Docker
  • Microservices
  • REST API
  • MongoDB
  • MySQL
  • Linux
  • Cloud Platforms
  • CI/CD

Projects

Selected work

End-to-end systems and products I've designed, built, and shipped.

Scalable Distributed Service for Twinder

Distributed Java dating service handling ~500M daily requests with Redis caching and AWS EC2; CQRS storage and Kafka partitions reduced dispatch time 200ms→100ms; stress tests showed 2k→6.6k req/s and 200→30ms latency.

  • Java
  • Spring
  • MongoDB
  • Redis
  • Kafka
Job Board Platform

Job Board Platform

Full Stack Developer

Full‑stack job posting app with Node.js REST APIs and React UI; JWT auth with bcrypt; responsive design; deployed on Heroku with MongoDB Atlas and Cloudinary.

  • React
  • Node.js
  • Express
  • MongoDB
  • Cloudinary
Discord Food Delivery Bot

Discord bot for food ordering and restaurant info using Java/JDA and MongoDB Atlas; DI & MVC architecture; built with Gradle and deployed on Fly.io.

  • Java
  • JDA
  • MongoDB
  • Fly.io
Campsite Review Explorer

Campsite Review Explorer

Full Stack Developer

Full‑stack JS app for browsing campsite reviews and comments; RESTful APIs with CRUD; MongoDB Atlas for data and Cloudinary for images; deployed on Heroku.

  • Node.js
  • Express
  • MongoDB
  • Redux
  • Heroku

Skills

Tools I ship with

A practical toolbox across languages, frameworks, and cloud infrastructure.

Languages

  • Java
  • TypeScript
  • Python
  • JavaScript
  • C++
  • C

Backend & APIs

  • Node.js
  • Express
  • NestJS
  • Django
  • REST
  • gRPC

Architecture

  • Domain-driven design
  • Event-driven
  • CQRS
  • SAGA
  • Observability

Frontend & UI

  • React
  • Next.js
  • Tailwind CSS

Cloud & Data

  • AWS
  • PostgreSQL
  • MySQL
  • MongoDB
  • Redis
  • Apache Kafka
  • RabbitMQ

Platform & DevOps

  • Docker
  • Kubernetes
  • CI/CD
  • Jenkins
  • Git
  • Microservices

Education

Foundations of my craft

  • Master of Science in Computer Science

    Northeastern University

    2021 – 2023 · Seattle, WA

    Focus on distributed systems and cloud computing

Contact

Let's collaborate

Have an idea or role that could be a great fit? I'd love to hear from you.