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n.today

Noel

Founder · Software Engineer

Seven years building backends, mostly in finance and security — B2B services and authentication systems. Alongside that I ship iOS apps and web work alone, from the first idea to the deploy. When one person holds the app, the web, and the server, nothing leaks at the seam.

Experience

Backend and full-stack at one company since 2019. Before that, eight months freelancing on web projects. Here is what I worked on.

  1. 2025.09 —

    Security assessment SaaS

    A subscription security-assessment service for small businesses. I designed the backend API and system architecture, and built the assessment server and agents.

    • Automated checks spanning web malware and vulnerabilities, systems, networks, and wireless
    • A matching system that recommends a fitting security product straight from the findings
    • Live assessment wired to the national threat-intelligence feed
    • Subscription SaaS model with automatic agent installation and payment integration
    KotlinSpring BootJPA · JooQDockerMQTTReactTypeScript

  2. 2025.05 —

    Blockchain software-licence tracking

    A platform that verifies licence-record integrity on a consortium blockchain. I owned the backend API, the chain integration, and the tracking modules.

    • Licence integrity verified through consortium-blockchain tokens
    • Windows and Linux agents detecting unlicensed use in real time
    • Automated infringement reporting from distribution monitoring
    • Language wrappers for C#, Java, and Python
    KotlinSpring BootPostgreSQLC · C++Next.jsBlockchain

  3. 2024.03 —

    B2B remote certificate issuance

    Designed and automated per-business certificate issuance, from data modelling through legacy integration.

    • Automated a manual issuance process, cutting handling time and operator load
    • Moved the bulk path from JPA to MyBatis to speed up reads
    • Security architecture for handling sensitive data
    • Integration with legacy systems in a JEUS enterprise environment
    JavaSpring BootJEUSJPA · MyBatisOracle

  4. 2024.01

    Company site rebuild

    Rebuilt as a static site, cutting both load time and release friction.

    • Rebuilt as a static site, cutting load time and shortening the release cycle
    Next.jsTailwind CSSTypeScript

  5. 2022.03 — 2022.10

    Automated security assessment

    Defined attack scenarios up front and ran the checks automatically. Built both the backend API and the frontend.

    • Automated a manual assessment process, cutting the time it takes
    • Deployed to a customer test environment
    KotlinSpring BootQueryDSLDockerMQTTReact

  6. 2021.03 — 2021.10

    Enterprise Wi-Fi SDK

    Built distributable iOS Framework and Android AAR SDKs, and maintained the apps on both sides.

    • Optimised Network Extensions and Keychain integration to cut crashes
    • OTP-based one-time passwords for automatic enterprise Wi-Fi connection
    • Multi-device support through ticket issuance
    • Self-signed and trusted-CA certificate handling
    SwiftUIKit · SwiftUIKotliniOS FrameworkAndroid AAR

  7. 2021.01 — 2021.04

    Internal recognition web service

    An internal service behind AD SSO. I designed and built it.

    • Internal participation rose after launch
    C#ASP.NET Core MVCEntity Framework Core

  8. 2020.03 — 2020.11

    IoT and biometric step-up authentication

    Designed the server and client authentication flow and built the backend.

    • A step-up prototype reduced authentication failures
    • C JNI integration
    JavaSpring BootQueryDSLDockerC JNI

  9. 2019.05 —

    Biometric product back office

    Designed and built the admin pages, licence management, and file encryption back office for a Windows biometric product line.

    • Migrated the licence management page from React to Thymeleaf
    JavaSpring BootQueryDSLThymeleafDocker

  10. 2018.12 — 2019.07

    Freelance web development

    A company site end to end, a profile registration system for recruitment, and a retail promotion page.

    JavaSpringC#MSSQLjQuery

Stack

Primary
JavaKotlinSpring BootJPA · JooQ · MyBatis
Data & infra
OraclePostgreSQLDockerAWSJEUS
Mobile
Swift · SwiftUIUIKitAndroid (Kotlin)SDK work
Frontend
TypeScriptReact · Next.jsTailwind CSS
Also
C · C#MQTTBlockchain integrationLinux

Education & certification

  • BSc Computer Science, Korea National Open University (2021 – 2023)
  • Engineer Information Processing (2022)
  • SQL Developer (2024)

How I work

  • Define the problem before listing features.
  • Ship small, use it, delete what goes unused.
  • Design with post-launch operations in mind.