About
Hello! My name is Seulkiro. I love building web applications.
I started my journey into web development back in 2018, when I helped my team develop a proof-of-concept web app despite having zero front-end experience, I was there to fill the gap in our front-end skills.
I was hooked instantly. Since then, I've developed apps not just for the companies I've worked with, but also through my own side projects. Examples include puzzle games, ineractive race maps, meal kit e-commerce platforms, productivity trackers, Git repository management tools, and more.
When I'm not at the computer, you'll usually find me making coffee, running, cycling, or reading a good book.
Experience
2025 — Present Full Stack Developer · NestedTree
- Build and ship high-quality full-stack web applications for diverse use cases (e.g., productivity trackers, meal kit platforms, endurance race maps), emphasizing scalability, code quality, performance, and user experience.
- JavaScript
- TypeScript
- React
- Next.js
- Node.js
- AWS
- PostgreSQL
2014 — 2024 Software Development Engineer · Amazon
- Led a team of software engineers to design and implement interview screening schedule automation for a high-traffic internal applicant tracking system.
- Collaborated with leadership to deliver production service integrations and user-facing features, significantly improving internal customer productivity.
- Developed an ETL upstream service to process and enrich invoice data, enabling machine learning models to detect duplicate invoices with 90% accuracy and substantially reducing manual review effort.
- Built a feature for Amazon Mobile product detail pages that aggregated real-time data from downstream services to display Prime delivery badges and messages, supporting the company-wide same-day delivery initiative.
- JavaScript
- TypeScript
- React
- Ruby on Rails
- Java
- AWS
- PostgreSQL
2009 — 2014 Software/Firmware Development Engineer · DataCan Services
- Led development of the primary software suite for high-temperature downhole gauges, enabling real-time monitoring and data analysis for the oil industry.
- Designed and optimized embedded firmware for wireless data transmitters.
- Developed real-time logging software to support downhole gauges.
- .Net
- C#
- PIC Assembly
- MySQL
2006 — 2007 Software Development Engineer Intern · SMART Technologies
- Developed cross-platform libraries and software for SMART electronic whiteboards, enabling seamless integration and enhanced interactivity.
- C++
- QT
- MFC
Projects
Krasing
A web application that streamlines your daily routine by tracking and managing tasks while challenging you to build better habits.
- React
- Node.js
- Express
- PostgreSQL
- Heroku
RepoRay
An all-in-one code contribution management that unifies scattered git contribution graphs across different service providers, currently supporting GitLab and GitHub.
- React
- Node.js
- Express
- GitHub/GitLab APIs
- Stripe
- Heroku
Gogit
A DoorDash-inspired web store for meal kits. It featured seamless order and payment systems with real-time inventory management, enriching user experience.
- React
- Node.js
- Express
- AWS
- Stripe
- Heroku
- PostgreSQL
puzzl.io
A picture-based puzzle maker, from 3x3 sliding to jigsaw puzzles, featuring hidden surprises like messages, links, and location revealed upon solving to boost engagement.
- React
- Node.js
- Express
- AWS
- Stripe
- Heroku
- PostgreSQL
Articles
Serving and Accessing Static Files in Express
A quick tutorial explaining how to serve static files in an Express.js app using the built-in express.static middleware.
- Node.js
- Express
Make Heroku App Dance With Cloudflare
How to connect a custom domain to a Heroku-hosted app with full HTTPS support, using Cloudflare as the DNS provider and proxy.
- Heroku
- Cloudflare
Deploy Node.js App with GitLab CI/CD
A practical step-by-step tutorial showing how to automatically deploy a simple Node.js (Express) application to Heroku using GitLab CI/CD pipelines.
- Node.js
- Express
- GitLab
- Heroku
Contact
I'm always open to new opportunities. Whether you have a question, a project idea, or just want to say hello, feel free to reach out (my inbox is always open), and I'll do my best to get back to you!
Say Hello