Jin Oh · Full-stack developerContact

P-05 · Enterprise · In-house · 2018 — present

Mircom Group of Companies

Eight years as the in-house developer who takes enterprise systems from legacy to modern — licensing, web, data and AI.

Role
Software Developer — sole developer on most projects, from architecture to maintenance
Timeline
Feb 2018 — Present
Platforms
Customer & admin portals · Corporate web · Internal tools
Links
mircom.com ↗
.NET / C#Flutter WebMS-SQLReactNext.jsTypeScriptMaterial UIAWS EC2WordPressPHPSupabaseOpen WebUI

TL;DR

At Mircom Group of Companies, a global fire-alarm and building-technology manufacturer, Jin Oh has led about 90% of assigned projects end to end since 2018. Highlights: rebuilding an undocumented Java-applet licensing system (transfer success 65% → 97%), moving a CodeIgniter app to Next.js on AWS (32% faster), migrating 300,000+ records from Joomla to WordPress with zero loss, and building an AI task tracker that writes executive summaries and SR&ED reports.

Key facts

  1. 01Reverse-engineered an undocumented Java-applet licensing system into .NET, C# and Flutter Web, raising security-dongle data-transfer success from 65% to 97%.
  2. 02Migrated a PHP/CodeIgniter web app to React, Next.js, TypeScript and Material UI on AWS EC2 without changing the database schema — 32% faster page loads.
  3. 03Built a data pipeline that moved 300,000+ legacy records from Joomla to WordPress with restructured metadata and zero data loss.
  4. 04Built an AI task-tracking platform (Next.js, Supabase, Open WebUI) that automates daily executive summaries and SR&ED tax-credit reporting.
  5. 05Built and maintained the corporate WordPress site for eight years: training portal with automated certificates, regional pricebooks, brochure ordering and eCommerce.
  6. 06Worked directly with Product Management, QA, Marketing, Training and RMA departments.
  • 97%transfer success (from 65%)
  • 32%faster page loads
  • 300,000+records migrated, zero loss
  • 90%of projects led end to end

The problem

Mircom designs and manufactures life-safety and building-automation systems sold worldwide. Its software licensing, dealer tools and corporate web had grown over many years on technology browsers no longer supported.

The job: modernise without breaking what dealers and customers rely on every day — and keep shipping new tools as the business asks for them.

Who it serves — and what they needed

  • Product Management & QALicensing that works on every modern browser, verified before release.
  • MarketingA corporate site they can update, with SEO and campaigns that ship on time.
  • Training & RMAOnline courses that issue certificates; brochure and service workflows without paperwork.
  • Executives & FinanceDaily summaries and SR&ED claim evidence without spreadsheets.

How it fits together

FIG.Systems modernised
requestRESTlicencelocalwritesame schemapipelinelog timesummariseUSERDealers & customersModern browsersAPPESD portalFlutter WebSVC.NET APIC#DBMS-SQLSchema preservedAPPNext.js appReact · TS · MUI · AWS…SVCWindows bridgeCustom C# appAPPCorporate WordPressCustom theme & pluginsEXTLegacy Joomla300,000+ recordsDEVICESecurity dongleWibuKey · CodeMeterUSEREngineers & execsMulti-officeAPPAI time trackerNext.js · SupabaseAILLMOpen WebUI
  1. 01A licence is written to a dongle — no Java appletDealers & customers → ESD portal → .NET API → MS-SQL · ESD portal → Windows bridge → Security dongle
  2. 02Legacy apps rebuilt on the same dataNext.js app → MS-SQL · Legacy Joomla → Corporate WordPress
  3. 03Time entries become executive reportsEngineers & execs → AI time tracker → LLM

What’s inside

ESD licensing portal

  • Customer and admin portals in Flutter Web
  • .NET API in C# over MS-SQL
  • Custom C# Windows bridge for WibuKey and CodeMeter dongles

Legacy web modernisation

  • CodeIgniter → React / Next.js / TypeScript / Material UI
  • Hosted on AWS EC2
  • Database schema untouched — zero migration risk

Corporate website

  • Custom WordPress theme and plugins
  • Online courses with automated certificates
  • Regional pricebooks, brochure ordering, eCommerce

Data migration

  • Joomla → WordPress pipeline
  • 300,000+ records with metadata restructuring
  • Zero data loss

AI & internal tools

  • Engineering time tracker with AI-written summaries (Open WebUI)
  • SR&ED tax-credit reporting automated
  • Mircom Connect — internal news and recognition platform

Projects at Mircom

  • ESD Portal

    Customer and admin portals managing WibuKey and CodeMeter security dongles through a custom C# Windows application.

    → 65% → 97% transfer success

    .NETC#Flutter WebMS-SQL
  • Corporate website

    Custom theme and plugins — online courses with certificate generation, regional pricebooks and eCommerce. Built and maintained for eight years.

    WordPressPHPMySQL
  • Engineering time tracker

    Multi-office timesheet portal with daily project tracking, detailed reports and AI-summarised executive reports.

    → SR&ED reporting automated

    Next.jsSupabaseOpen WebUI
  • Mircom Connect

    Internal social platform for employees to share news, announcements and achievements across the company.

    Next.jsSupabase
  • Legacy app migration

    CodeIgniter app rebuilt on the existing schema.

    → 32% faster page loads

    ReactNext.jsTypeScriptMaterial UIAWS EC2
  • Joomla → WordPress

    Custom migration pipeline with metadata restructuring.

    → 300,000+ records, zero loss

    PHPMySQL

Hard parts, solved

  1. C-01

    A licensing system nobody documented

    Problem

    Licences were written to hardware dongles through a Java applet that modern browsers no longer run; the original code had no documentation and transfers failed about a third of the time.

    Approach

    Reverse-engineered the applet’s protocol, rebuilt it as a .NET API plus a small C# Windows bridge for the dongle, and put a Flutter Web portal in front.

    Result

    Transfer success rose from 65% to 97% on every modern browser.

  2. C-02

    Modernise the app, keep the database

    Problem

    A CodeIgniter app was slow and dated, but other systems depended on its database.

    Approach

    Rebuilt the front and back end in Next.js and TypeScript against the existing schema, deployed on AWS EC2.

    Result

    32% faster loads and a modern UI with zero data migration.

  3. C-03

    300,000 records, zero loss

    Problem

    Moving from Joomla to WordPress meant reshaping metadata that did not map one-to-one.

    Approach

    A custom, re-runnable pipeline that transformed and verified every record and its metadata.

    Result

    300,000+ records migrated with nothing lost.

  4. C-04

    Turning timesheets into tax credits

    Problem

    SR&ED claims and executive updates were assembled by hand from spreadsheets.

    Approach

    A Next.js + Supabase tracker where engineers log daily work; an LLM through Open WebUI drafts executive summaries and SR&ED narratives.

    Result

    Manual spreadsheet reporting eliminated.