First Name Han
Last Name Lim
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Zendesk Pte Ltd

Designation Principal Engineer
Period Nov 2018 - Current (7 years)
Scope  Group Tech Lead for the Agent Workspace Messaging Teams based in Singapore. I was one of 3 Group Tech Leads who was charged with technical leading responsibilities to roll out a multi-year program to revamp the Messaging experience for Zendesk's Agent Workspace. In 2024, I was also charged with starting a service that would provide AI capabilities to the Agent Workspace and one of the feature we rolled out was a Suggested Reply feature for assisting agents in replying to customers faster.
Achievements  Successfully rolled out the first phase of the program which replaces a legacy messaging system with a new one that is built on top of Kafka and Java. The new system is able to handle at least 10x the load of the legacy system and is able to scale horizontally. The new system is also able to handle the new requirements of the Messaging product which includes a tighter integration with the Conversation product Sunshine Conversations (formerly known as Smooch.io)

• Wrote some of the initial RFCs/ADRs for some of the critical components in the new Messaging backend system
• Wrote some of the services responsible for delivering the conversational payloads in the Messaging system
• Advised and mentored teams in rolling out the changes required for the new Messaging backend
• Pioneered a Java-based service for powering AI capabilities in Agent Workspace

Eyeota Pte Ltd

Designation Senior Backend Engineer
Period Mar 2016 - Nov 2018 (2 years)
Scope  Member of Tech team working on a high volume and low latency system for processing and delivering Internet browsers cookie based data. The system is deployed across multiple regions around the globe and relies on Apache Kafka and Cassandra for distributed messaging and storage
Achievements  Wrote and implemented microservice components for a greenfield system that crawls the content of pages that Internet users surf and tries to classify those content into a range of Advertising audience segments.

• The system is a Java-based project using technologies like Kafka, Cassandra and Undertow Web Server that can achieve processing rates of ~12k/s
• Co-wrote a file-based cache for serving requests that uses Java NIO MappedByteBuffers providing a fast lookup for 30GB of data
• Involved in scaling a url crawling/classification system that can process up to 150 urls/s

Wireless Data Services, A Xerox Company

Designation Senior Software Engineer
Period June 2011 - Feb 2016 (4 years 4 months)
Scope  Member of an agile team of software developers responsible for core strategic software in the business. The engineering capabilities required from our team is multi-faceted due to the wide range of technologies used as well as the fast pace of deliverables in an agile environment
Achievements  As a core member of the Development team, I have been integral to the development and delivery of various projects by applying knowledge of technologies like the following:

• One of the lead developers who are charged with the delivery of a cutting edge social monitoring application that has its roots from PARC, A Xerox Company
• Laying down the architectural vision of the new version of Social Monitoring product
• Java-based projects using technologies like Spring, Maven, Ant, Play! Framework
• Ruby on Rails projects with exposure to accompanying technologies e.g. RVM, Gems
• Adhoc projects that requires Linux scripting skills in bash
• Continuous Integration process using Jenkins

STMicroelectronics Pte Ltd

Designation Senior System Analyst
Period July 2007 - May 2011 (4 years)
Scope  Team leader for a group responsible for developing and maintainance of internal software systems necessary for the operations within the semiconductor business. I'm responsible for some portion of human resource management but mainly on technical leadership of the projects in the team
Achievements  As a team leader of a small software team, I have to ensure that the applications that are under our charge are operational at all times. We also need to ensure that the change/incident request processes are adhered to via Remedy. I was also placed in charge of various projects during my time there including

• A Java Struts-based Training and certifications application deployed on Tomcat
• A web-based UI that integrates with production plant systems via web-services providing visualization and operations of those systems. The web application is written in Struts and deployed in JBoss. However, the integration portion requires knowledge of C/C++ SOAP development
• Adhoc projects that requires Linux scripting skills in bash

CrimsonLogic Pte Ltd

Designation System Analyst
Period June 2004 - July 2007 (3 years)
Scope  System analyst responsible for maintaining and implementing various components of Singapore Government's eTrade application, TradeNet 4.0. I was responsible for customer requirements gathering, documentation and development for the components in the TradeNet application
Achievements  I was placed in charge of key modules in TradeNet that involves knowledge of Trade and Logistics domain knowledge and J2EE and its related technologies.

• Learnt to develop and deploy enterprise scale Java web applications deployed in Weblogic
• Responsible for key modules within TradeNet's backend processing application
• I was in charge of ACCESS, another Java web application that processes manifests and issues permits to air logistics companies like DHL, Fedex, TNT and UPS.

Professional Qualifications

• Linux Professional Institute LPIC-1
• Project Management Professional (PMP)
• Oracle Certified Java Programmer

Professional Experiences

Programming Languages [ Strength from Weak(1) to Strong(10) ]

• Java (7)
• Javascript (4)
• Bash Scripting (5)
• Python (4)
• Ruby (4)
• Golang (5)

Web development (Java)

• Play! Framework
• Spring Framework
• Maven, Ant, Gradle

DevOps Experience

• Puppet
• Ansible
• Amazon Web Services
• Kubernetes

Testing & Best Practices (Java)

• JUnit
• AssertJ
• Selenium
• Mockito
• Jenkins Continuous Integration
• Atlassian Suite (JIRA, Bamboo, Stash, Confluence)

Web development frameworks (Others)

• Ruby on Rails (2 years)
• Node.js (Beginner)
• AngularJS

Linux Skills

• Bash shell scripting
• Shell commands
• Vim

Distributed Systems

• Apache Cassandra
• Apache Kafka

Software configuration management

• Git

Interests (Things I would like to learn)

• ElasticSearch
• Apache Spark
• Deep Learning

Spoken/Written Languages

• English
• Mandarin
• A smattering of Cantonese
• A dose of Hokkien

Software Projects

• Github Profile (https://github.com/singularity-sg)
• Ported liblinear, a scalable machine learning library to Golang without C-bindings. (Pure Golang)

Academic Background

Nanyang Technological University (Singapore)
Bachelor of Computer Engineering (Honours)

Public Speaking

Co-presented on 2 topics for various meetup groups (Java User Group). See here

Aptitude Tests

GMAT

Verbal - 36 (80%)
Quantitative - 42 (67%)
Analytical Writing - 5.5/6 (87%)
Total - 640 (80%)

GRE

Verbal - 162 (90%)
Quantitive - 160 (84%)
Analytical Writing - 4.0 (48%)
Total - 322