OldChong - Portfolio

About me

I'm a seasoned full-stack developer from Johor, Malaysia, currently serving as a Software Engineer with a leading paytech company in Singapore. With a strong passion for tackling complex challenges, I specialize in designing and implementing innovative solutions for financial systems.

As a full-stack developer, I am proficient in both front-end and back-end technologies. My expertise spans older front-end frameworks such as Struts and ZK, as well as modern technologies like Angular. My diverse skill set extends to backend development with professional experience in Java and ASP Classic, allowing me to build robust and scalable server-side solutions. This comprehensive expertise enables me to create cohesive and high-performing applications that drive business success and meet evolving industry standards.

What I'm Doing

Web Design

Creating user-friendly designs that enhance user experience.
Web Development

Building responsive websites that meet modern standards.
Mobile Apps

Developing intuitive mobile applications for iOS and Android.
Photography

Capturing high-quality images for various professional needs.

Resume

Education

Universiti Teknologi Malaysia
Oct 2024 - Present
Master of Computer Science

Current CGPA: 3.87 / 4.00
Universiti Malaysia Terengganu
Sep 2018 - Feb 2022
Bachelor of Computer Science (Software Engineering)

CGPA: 3.74 / 4.00

Experience

Software Engineer

Worldline, Singapore
Apr 2023 - Present
Software Engineer

Theta Service Partner, Malaysia
Mar 2022 - Mar 2023
- Designed dynamic and customized reports using JasperReports.
- Implemented data retrieval from external systems using SOAP APIs.
- Enhanced workflow functionality using Java Workflow Designer to improve business logic execution.
- Developed secure and scalable RESTful APIs with JWT authentication using the HS256 algorithm.
- Implemented file transfer in and out using RabbitMQ ensuring efficient data handling.
- Constructed multipart APIs for encrypted file and data transfer along with JWS.
- Secured symmetric key encryption with RSA-OAEP and implemented RSA 2048 for data and file integrity.
- Built WAR packages using Jenkins and performed deployment to IBM WebSphere.
Intern Software Engineer

Theta Service Partner, Malaysia
Aug 2021 - Feb 2022
- Designed front-end pages using ZK framework.
- Developed Java-based calculations for financials assets.
- Enhanced business rule with Oracle SQL scripts for loan assessments.

Certifications

Oracle Certified Associate, Java SE 8 Programmer
Feb 2023
Oracle Certified Foundations Associate, Java
Feb 2023

My Skills

Programming Languages
- Java
- JavaScript/TypeScript
- Python
- HTML
- CSS
- SQL
- PHP
- Go
- Kotlin
Testing & API Tools
- JUnit
- JMeter
- Rest API
- SOAP API
- gRPC API
- Postman
- SoapUI
- Swagger
Frameworks & Libraries
- Spring
- Spring Boot
- Hibernate
- Ajax
- Angular
- ZK
- Struts
- JSP
- Classic ASP
- RabbitMQ
- Kafka
- JasperReport
Development Tools
- Eclipse
- Visual Studio
- IntelliJ
- GitLab
- Jenkins
- IBM WebSphere
- Apache Tomcat
- JBoss Application Server
- Docker
- Kubernetes
- OpenShift
Database & Data
- MySQL
- PostgreSQL
- Oracle
- MariaDB
- JSON
- XML
System Tools
- TortoiseSVN
- PuTTY
- WinSCP
- Jira
- Confluence
Internet of Things (IoT)
- Arduino
- ESP32
- MQTT
- MIT App Inventor
Payments
- ISO 8583
- TCP/IP
- Acquiring
- Issuing
- HSM
Artificial Intelligence (AI/ML)
- Supervised Learning
- Unsupervised Learning
- Association Rule Mining
- Convolutional Neural Network (CNN)
- Multilayer perceptron (MLP)
- Artificial Neural Network (ANN)
- XGBoost
- K-means Clustering
- Deep Learning

Contact

Contact Form

Tools

Base64 Decoder

Base64 Input:

Byte Array:

Hex String:

Hex String (No Spaces):

Decimal-Hex Converter

Decimal:

Hexadecimal:

Conversion Process

Decimal to Hex

Hex to Decimal

Visual Grid (16×16)

ASCII-HEX Converter

ASCII:

HEX:

Formatted HEX:

Byte-String Converter

Byte Input:

String Input:

RSA Encryption and Decryption

Generate RSA Key Pair

Select RSA Key Size:

Public Key:

Private Key:

RSA Encryption

Enter Plain Text to Encrypt: Enter Public Key:

Encrypted Output (Base64):

RSA Decryption

Enter Encrypted Text to Decrypt (Base64): Enter Private Key:

Decrypted Output:

ISO8583 Bitmap Calculator

Bitmap:

Formatted Bitmap:

Select Fields:

ISO8583 Message Builder (Developing / Not Working)

Built Message:

Bitmap:

Total Length Type:

Field Configuration

Field Type Length Padding Padding Char Value

What I'm Doing

Web Design

Web Development

Mobile Apps

Photography

Education

Universiti Teknologi Malaysia

Universiti Malaysia Terengganu

Experience

Software Engineer

Worldline, Singapore

Software Engineer

Theta Service Partner, Malaysia

Intern Software Engineer

Theta Service Partner, Malaysia

Certifications

Oracle Certified Associate, Java SE 8 Programmer

Oracle Certified Foundations Associate, Java

My Skills

Programming Languages

Testing & API Tools

Frameworks & Libraries

Development Tools

Database & Data

System Tools

Internet of Things (IoT)

Payments

Artificial Intelligence (AI/ML)

OldChong Blog (Developing)

Contact Form

Base64 Decoder

Decimal-Hex Converter

Conversion Process

Decimal to Hex

Hex to Decimal

Visual Grid (16×16)

ASCII-HEX Converter

Byte-String Converter

RSA Encryption and Decryption

Generate RSA Key Pair

Public Key:

Private Key:

RSA Encryption

Encrypted Output (Base64):

RSA Decryption

Decrypted Output:

ISO8583 Bitmap Calculator

Bitmap:

Formatted Bitmap:

Select Fields:

ISO8583 Message Builder (Developing / Not Working)

Field Configuration