Jay Kim
Open to contract and full-time roles(Toronto · Remote-friendly)Let's talk
ReactNext.jsSpring BootCloud

JAY KIM

Frontend · Full-Stack · Backend Web Developer

React-focused engineer who ships production systems end to end and is comfortable shaping APIs, modeling data, and tightening frontend UX.

Hire MeView Projects
Toronto-based · Working worldwide

Professional Summary

I focus on designing, developing, and integrating end-to-end web products. React/Next.js is my home base, but I stay hands-on through API design, data modeling, and delivery so the whole surface feels cohesive.

  • Consistently deliver high-performance, accessible React interfaces that meet or exceed industry standards for speed and user experience.
  • Design secure RBAC/RLS back ends, multilingual routing, and analytics instrumentation so features are ready for growth.
  • Lead small squads or solo engagements with the same discipline-architecture, delivery, and cloud ops included.

Technical Skills

Hands-on stack across product, platform, and delivery.

Languages
Core
JavaScriptTypeScript
Supporting
Java
Frontend
Core
ReactNext.js (App Router)Tailwind CSSReact Hooksi18n
Supporting
SCSSRedux ToolkitContext API
Refresh needed
Styled ComponentsAxiosAnt DesignBootstrapMaterial-UIEmotionSWRSocket.IOApollo ClientApexChartsStorybook
Ramp-up required
Redux-SagaGatsbyJSPjQueryAjaxThymeleaf
Backend & Full-Stack
Core
Node.js
Supporting
Express.jsSupabase (Auth / Storage / RLS / Database)REST APIJWT AuthSwaggerSpring BootJPASequelizeSpring Cloud (Gateway / OpenFeign)
Refresh needed
Apollo ServerSpring Cloud (Config / Eureka / Circuit Breaker)KafkaRabbitMQ
Ramp-up required
Spring Webflow
Cloud & Deployment
Core
Vercel
Supporting
AWS (EC2 / S3 / IAM / Lambda)Custom Hosting & DNS
Refresh needed
AWS (SES / SNS / CloudWatch / CodeCommit)Private Cloud
Ramp-up required
On-premises
Databases
Supporting
PostgreSQLMySQL
Refresh needed
MongoDBTiberoOracleMariaDB
Ramp-up required
Microsoft SQL ServerInformix
Build Tools & Testing
Supporting
MavenGradleJUnitJestReact Testing Library (RTL)Playwright
Version Control
Core
Git (GitHub / CodeCommit / Bitbucket / GitLab)
Refresh needed
SVN
AI
Core
Codex
DevOps & Collaboration
Core
Cloudflare
Supporting
PM2Google Analytics
Refresh needed
DockerJiraConfluenceJenkins
Ramp-up required
Observability (Spring Boot Actuator, Micrometer, Prometheus, Grafana)
Architecture & Practices
Core
Modular UI / Atomic DesignCI/CDAccessibilityPerformance-Optimization
Supporting
MicroservicesTDD
Ramp-up required
Monolithic ArchitectureMicro Frontend (MFE)

Case Studies

A sample of platforms I have led recently.

SERVITH
Portfolio & Case Studies Website (2025)
Nov 2025 - Nov 2025
servith.com

Personal portfolio showcasing services, case studies, and bilingual content (EN/KR). Uses App Router with per-page dynamic metadata, MDX-driven case studies, and reusable UI sections for rapid updates.

ReactNext.jsTypeScriptTailwind CSS
SERVITH
M.S.W., R.S.W. Counselling & Psychotherapy Site
Oct 2025 - Oct 2025
servith.com

Therapy brochure site for a registered social worker, featuring service pages (individual/couples), therapist bio with credentials, resources & crisis info, FAQ, and a secure contact/intake form. Built with modular sections to support quick edits and clinic updates.

ReactNext.jsTypeScriptTailwind CSS
SERVITH
SERVITH Portal
Sep 2025 - Oct 2025
servith.com

Client/admin portal that manages the full workflow from inquiry → quote → project with secure file sharing and status tracking.

ReactNext.jsTypeScriptTailwind CSS
View all projects

Experience

Selected engagements across product, platform, and banking.

01
Independent Web Developer
SERVITHEtobicoke, ON (Remote)Oct 2024 - Present

Partnering with founders across North America to ship marketing sites, portals, and Supabase-powered apps.

  • Built App-Router Next.js 15 sites with TypeScript + Tailwind, keeping Lighthouse scores at 95+ and FCP < 1s.
  • Created Supabase-backed client/admin portal with RBAC/RLS, signed uploads, and inquiry → quote automation.
  • Integrated next-intl SEO, GA4, chat, and consent flows while reducing ops spend ~30% via managed services.
  • Monitored messaging using AWS SES/SNS/CloudWatch/Lambda for bounce/complaint tracking.
Next.jsReactTypeScriptTailwind CSSSupabasePostgreSQLAWS

Delivered commerce, chatbot, and dashboard products for enterprise clients across Spring Boot, React, and OCC.

  • Owned 8+ launches covering Next.js SSR/ISR storefronts, Spring Boot APIs, and Express.js services.
  • Raised Java unit test coverage from 45% to 82% using JUnit/Mockito and hardened CodeCommit pipelines.
  • Migrated REST APIs to Express.js cutting CPU usage 33% and enabling 30% AWS compute savings.
  • Implemented PLP/PDP/RFQ experiences and ISR builds with <200 ms TTFB plus JSON-LD SEO automation.
Spring BootReactNext.jsNode.jsExpress.jsSCSSOracle Commerce CloudAWSKafkaRabbitMQ

Built self-initiated full-stack products with React/Next.js and Spring Boot, deployed on AWS/Docker.

  • Launched dashboards, authentication, and email workflows using React, Next.js, and Spring Boot.
  • Managed Docker/Jenkins/PM2 pipelines on AWS EC2 while handling infra, DNS, and SSL.
  • Designed responsive UIs with Ant Design, Styled Components, and Bootstrap themes.
  • Optimized bundles/Core Web Vitals to lift organic traffic by 35% via SEO + Webpack tuning.
ReactNext.jsSpring BootAnt DesignStyled ComponentsAWS EC2DockerJenkins

Modernized large-scale banking systems (Withholding Tax, Transaction Management) across Java, React, and Tibero.

  • Led 1 TB Oracle → Tibero migration and automated 6 tax workflows with zero compliance violations.
  • Digitized 28M transaction records, saving CAD 1.1M/year and running 99.9% ETL success.
  • Refactored JSP modules to React and optimized SQL across EasyBuilder → MyBuilder migrations.
  • Delivered DB-to-DB sync, electronic approvals, and private-cloud deployments as system admin.
JavaSpringReactJSPOracleTiberoUnixETL

Delivered enterprise groupware for 2,000+ employees, covering auth, collaboration, and CI/CD automation.

  • Implemented login, document sharing, bulletin boards, and attendance modules using Spring, JSP, and jQuery.
  • Set up Jenkins CI/CD pipelines that converted weekly FTP deployments into daily automated releases.
  • Partnered with stakeholders to translate requirements into functional modules and coordinated UAT.
SpringJSPjQueryMariaDBJenkinsTomcatCentOSSVN

Built and maintained enterprise security consoles (UAC, USL, SecuMS) deployed across 10+ organizations.

  • Developed Java/Struts2 admin dashboards and a memory-efficient 1 GB log viewer for forensic workflows.
  • Shipped role-based access control, session logging, and vulnerability assessment modules.
  • Collaborated with QA and client IT teams to deliver secure, stable releases in regulated environments.
JavaStruts2JSPjQueryMSSQLTomcatWindows ServerSVN

Articles

Notes on frontend, product, and shipping real-world projects.

Git Commands I Actually Use Every Day
Nov 1, 2025
Git Commands I Actually Use Every Day

You don't need the entire Git manual to work comfortably on real projects.This post focuses on a small set of Git commands that cover 95% of everyday workflows: status, diff, add/ commit, branching, remotes, undo, and stash.

  • Explains a practical lifecycle: clone, edit, status, diff, add, commit, and log.
  • Shows how to create, switch, and list branches using modern git switch and classic checkout.
gitcliworkflowversion-control
Read post ->
Deploying Next.js with Docker and Kubernetes
Sep 1, 2025
Deploying Next.js with Docker and Kubernetes

Next.js doesn't have to run on Vercel.This post shows how to containerize a Next.js app with Docker and run it on Kubernetes using a practical multi- stage Dockerfile, Deployment, and Service configuration.

  • Explains when Docker and Kubernetes actually make sense for a Next.js app.
  • Shows a realistic multi-stage Dockerfile for building and running Next.js in production.
nextjsdockerkubernetesdeploymentdevops
Read post ->
How to Actually Use Micro Frontends with Next.js (Without Drowning in Complexity)
Jul 1, 2025
How to Actually Use Micro Frontends with Next.js (Without Drowning in Complexity)

A step-by-step guide to splitting a Next.js app into multiple deployable frontends on Vercel, sharing a design system, and keeping auth/navigation feeling like a single product.

  • Shows how to split a product into marketing/app/docs apps on Vercel
  • Explains how to share a UI design system as a package across apps
nextjsmicro-frontendsarchitecturevercelmodular-monolith
Read post ->
View all articles

Contact

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