BACKEND SOFTWARE ENGINEER
EJ Jung
Product-minded Backend Engineer with 4+ years specializing in Java & Spring — building scalable systems and shipping products from 0 to 1.
I care about more than just writing code — I care about software quality, business needs, and the end users who actually use what I build. Currently co-founding Flowdi, a time-tracking app shipped end-to-end with AI-assisted development. App Store · Google Play
4+
Years Experience
10K+
Daily Orders Handled
70%
Delivery Time Reduced
10+
APIs Idempotency Design
TECHNICAL SKILLS
What I Work With
Languages
Backend & Frameworks
Infrastructure & DevOps
Databases
WORK EXPERIENCE
Where I've Worked
Full Stack Software Engineer / Co-Founder
A cross-platform mobile time-tracking application providing statistics for time flow.
- ▸Owned end-to-end engineering from system architecture to App Store / Google Play deployment.
- ▸Leveraged Claude Code as an agentic coding agent to deliver a React Native/Expo app with no prior mobile experience.
- ▸Integrated Figma MCP to translate designer assets directly into production-ready components.
- ▸Replaced a full analytics DB with a Google Sheets logging pipeline to track user activity without infrastructure overhead.
Backend Software Engineer
E-commerce platform supporting nationwide retail and fulfillment services.
- ▸Built and launched a packaging system supporting 10,000+ daily orders for a new fulfillment center.
- ▸Reduced overnight delivery processing time by 70%+ with a bulk-complete feature, preventing order delays.
- ▸Ensured data integrity by implementing distributed locking, preventing race conditions across multi-user operations.
- ▸Refactored the Arrival API using the Factory Method pattern, achieving 70% code reusability.
- ▸Improved data consistency in Kafka-driven microservices by implementing failure recovery and retry mechanisms.
- ▸Designed an idempotent locking mechanism adopted across 10+ REST APIs, eliminating duplicate request side effects.
- ▸Reduced error detection time by 50% through real-time alerting.
Backend Software Engineer
Fintech startup providing personal pension asset management.
- ▸Integrated MyData API into a pension asset management system, ensuring full regulatory compliance.
- ▸Enabled asynchronous data propagation across distributed systems using RabbitMQ.
- ▸Automated CI/CD pipelines with Azure Pipelines, improving deployment speed and system reliability.
Volunteer Engineering Mentor
Nonprofit connecting students with industry mentors to build real-world tech experience.
- ▸Mentored 3 student developers on the p5.js open-source project with weekly sessions.
- ▸Turned around 2 weeks of zero progress by breaking down the codebase, enabling the team to merge their first open-source PR.
LEADERSHIP & COMMUNITY
Beyond the Code
Open Source Community Organizer
Seattle-based tech community focused on open source, AI, and data engineering.
- ▸Co-organized a Women + AI panel event for 100+ developers, leading event promotion and end-to-end logistics.
- ▸Contributing to the growth of the Seattle tech ecosystem through events and community partnerships.
Education
Chung-Ang University
Bachelor of Architecture
Graduated Feb 2021. Transitioned from architecture to software engineering — bringing a systems-thinking mindset and a structured approach to complex problem-solving.
Feb 2021CONTACT
Let's Connect
I'm open to new opportunities, collaborations, and conversations about distributed systems, AI-agentic development, or the Seattle tech scene.