Alvin de Leon, Developer in Baguio, Philippines
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Alvin de Leon

Verified Expert  in Engineering

Data Engineering Developer

Baguio, Philippines
Toptal Member Since
November 29, 2022

Alvin is a Software Developer with 18+ years of experience developing web back-end services in various domains and tech stacks. His strongest skills are in Java and Python, and he also has 8+ years of experience in dealing with Cloud service providers like AWS, build and release engineering, and data engineering. Alvin enjoys working on designing system architectures and solutions for rapid scaling and has significant experience working in startups and fast-moving teams with fixed deadlines.


iScale Solutions | Zetaglobal
Amazon Web Services (AWS), Amazon EC2, Elasticsearch, Amazon RDS...
Java, Spring Boot, JavaScript, CSS, HTML, ActiveMQ, Oracle
Java, Spring, JavaScript, Python, CSS, HTML, Django, MySQL, RabbitMQ, Jenkins...




Preferred Environment

Jira, Confluence, Slack, GitLab

The most amazing...

...redesign and development of a unified scoring platform that I've performed and scaled is now used for all the companies scoring needs.

Work Experience

Staff Software Engineer

2019 - PRESENT
iScale Solutions | Zetaglobal
  • Redesigned and re-implemented the scoring as a service platform into a unified scoring platform that can be used for PMML and python pickle-based models. This now supports scoring on the spark in AWS EMR to support big data.
  • Created partner exports to Yahoo!, Adwords, and Facebook. From Python celery based to Airflow with big data spark matching support.
  • Built an EMR profile that replaces bootstrap and uses AMI, which saves cost and time. This tool creates profiles, and each profile will create a custom AMI for specific EMR needs.
Technologies: Amazon Web Services (AWS), Amazon EC2, Elasticsearch, Amazon RDS, Amazon S3 (AWS S3), Amazon Elastic MapReduce (EMR), Java, Python, Django, JavaScript, HTML, CSS, Amazon ElastiCache, Spark, PySpark, Apache Airflow, Amazon Elastic Container Service (Amazon ECS), Docker, REST APIs

Principal Software Architect

2016 - 2019
  • Organized the re-architect of a heavy legacy messaging system to be a lightweight Java web application. Converted a J2EE application to a Spring Boot tomcat-based application.
  • Created a re-design and implementation of the message platform features for performance problems faced by clients.
  • Provided an architecture and design for Kafka based messaging system and a no-SQL solution for the future of the product.
  • Converted a J2EE application to a Spring Boot tomcat-based application.
Technologies: Java, Spring Boot, JavaScript, CSS, HTML, ActiveMQ, Oracle

Staff Software Engineer

2014 - 2019
  • Designed and implemented a scoring-as-a-service platform where analytics maintain PMML models and trigger scoring. This service has two modes, batch scoring, and real-time lead-based scoring.
  • Built the expression engine used for CDP for audience segmentation. We used expression string to identify an audience which then translated into proper SQL for data lakes like Redshift or Snowflake or query expression for Elasticsearch.
  • Implemented an analysis tool to visualize lead matching and won Hackathon.
Technologies: Java, Spring, JavaScript, Python, CSS, HTML, Django, MySQL, RabbitMQ, Jenkins, GitHub, GitLab, GitLab CI/CD, jQuery, Bootstrap 2, Snowflake, Redshift, Elasticsearch, AngularJS, Spring Boot, Amazon Web Services (AWS), Amazon RDS, Amazon EC2, Amazon Elastic Container Service (Amazon ECS), Amazon ElastiCache, Amazon Elastic MapReduce (EMR), Docker, PostgreSQL, REST APIs

Staff Software Engineer

2011 - 2014
Adchemy Philippines
  • Developed and maintained landing pages for lead generation.
  • Converted a flash-based web tool to Java web-based.
  • Implemented a workflow process though Jenkins that automates the work and reduces time from eight to two hours.
Technologies: Java, Jakarta Server Pages (JSP), MySQL, JavaScript, HTML, CSS, Spring, JUnit, Jenkins

Senior Software Engineer

2009 - 2011
  • Developed and maintained a value commerce portal, a web application for affiliate marketing.
  • Worked closely with product and UX team as a full stack java developer.
  • Monitored and profiled SQL executions. Built a tool that integrated with the Spring Framework and made a swing-based application that monitors and provides context logging.
Technologies: Java, Jakarta Server Pages (JSP), Spring, JavaScript, HTML, CSS, Swing, SQL, Oracle, JUnit, Mockito, Jenkins, Resin

Expert Software Engineer

2006 - 2009
  • Maintained and developed Midas plus, a financial banking system product. This is a Java 2 Platform, Enterprise Edition application with RPG as the back-end.
  • Recognized by our manager and moved to work as part of the architecture and development teams for the project's duration.
  • Designed and implemented an Ant-based tool used for building and packaging our project to be used before.
  • Contributed to the project, which led to winning a Living Our Values Award.
Technologies: Java, Enterprise Java Beans (EJB), Jakarta Server Pages (JSP), CSS, HTML, JavaScript, Ant Design, SQL, Jenkins, Spring, JUnit

Software Engineer

2004 - 2006
  • Worked as a full-stack java developer and maintained a web-based portal for an Accenture client.
  • Coordinated with the product manager for new features to be added and tasked with bug fixing.
  • Implemented an HTML parser that scraps a portion of a page from an existing internal site and displays it as a portlet in the portal application.
  • Received the first prize winner award of a design contest and also won multiple employee smart awards.
Technologies: Java, Jakarta Server Pages (JSP), Java Servlets, HTML, CSS, Enterprise Java Beans (EJB), SQL, Oracle, JavaScript, BEA WebLogic Server

Java Developer

2003 - 2004
Teams Training and CommzGate
  • Implemented text messaging gateway based on Java sockets, where for register and participate in contests and win prizes.
  • Created a web UI tool where we can monitor and build campaigns.
  • Supervised the launch process, where thousands of users joined.
Technologies: Java, Jakarta Server Pages (JSP), CSS, HTML, JavaScript, Apache Tomcat

Unified Scoring Platform

A python Django backed by a PostgreSQL AWS RDS for restful API as the platform facade. We also used Airflow DAGS for triggering the scoring of predictive model markup language and python pickle models. The scoring is executed in AWS EMR using a Spring Boot application for spark predictive model markup language scoring and a python script using PySpark for scoring python pickle-based models.

Scoring as a Service

This project consisted of a front-end and back-end service. There is a web-based UI for managing models for scoring that is made using Bootstrap, HTML, CSS, and JavaScript. The back-end was a Java Spring Boot application for restful service and is used to invoke real-time and batch scoring.

Partner Exports

A restful API used for partner export. Redesigned to include user matching to explode the users and handle big data to around 600 million users.

This project is a java spring-based robot framework library used by quality assurance engineers for automated testing. jSpringBot is a framework built on top of the robot framework to support Java and Spring. That allows you to end testing with ease using Maven.

I was the leading developer of this open source tool, Piraso. It is a development tool for debugging and analyzing request context log information captured from a supported java web application. Piraso currently supports SQL and Log4j context monitoring.

Audience Builder

A web-based application for CDP of around 1.7 billion users for audience segmentation. Involved in back-end work for providing restful API and providing the design and implementation for the audience segmentation engine used. We have used an expression-based string to query data lakes and elasticsearch for audience segments.
1999 - 2003

Bachelor's Degree in Information Technology

Saint Louis University - Baguio City, Philippines


PySpark, REST APIs, Java Servlets, jQuery


RabbitMQ, Celery, Amazon Elastic Container Service (Amazon ECS), Amazon Elastic MapReduce (EMR), Amazon ElastiCache, AWS Systems Manager, IntelliJ IDEA, Slack, Apache Maven, Jenkins, Apache Tomcat, GitHub, GitLab, GitLab CI/CD, ActiveMQ, Apache Airflow


Django, Spring, JUnit, Spring Boot, Spark, Jakarta Server Pages (JSP), Ant Design, Swing, Mockito, Bootstrap 2, AngularJS, Robot Framework


Python, JavaScript, HTML, CSS, SQL, Snowflake, Java, PMML


Docker, Amazon EC2, Apache Kafka, Oracle, NetBeans, Amazon Web Services (AWS)


Elasticsearch, Redis, Apache Hive, Amazon S3 (AWS S3), PostgreSQL, MySQL, Redshift


Data Engineering, Amazon RDS, Machine Learning, Enterprise Java Beans (EJB), BEA WebLogic Server, Resin, EMR

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