
Senior Software Engineer
DoorDash · Full-time
Nov 2022 - Present
• 2 yrs 6 mos- Search Platform Team
- Building our own Search Engine
Skills: Software Development · Regression Testing

MTS 1, Software Engineer
PayPal · Full-time
Oct 2018 - Nov 2022
• 4 yrs 2 mos• Work under Agile methodology to design and develop modules and functionalities
for multiple applications to perform administrative operations around Load
Balancer, DNS, Certificate and Bare Metal Provisioning.
• Led the team in removing distributed lock from Skynet(Load Balancer as as
service) and replace with generic optimistic lock detection and retry mechanism
integrated with JPA to improve performance, reliability to get application ready for
higher volume of traffic using by other teams.
• Designed and implemented Certificate Management suites (Compass, Certificate
Management Portal and Hub and Meridian, Certificate as a service) which is the
one-stop shop for TLS/SSL certificates life-cycle management and deployment.
Customers could utilize the suites to rotate certificates on VIPs in few clicks with
fully automated processes, and customers are provided with granular controls
over the events including immediate rollback ability. The application is now widely
used and contributes significantly in completing the ecosystem built around our
applications in PayPal and GoPay, China.
• Independently implemented Single-Transaction module in Skynet to boost
performance in large amount of concurrent service addition/deletion calls (up to
500 concurrent hosts sending multiple requests concurrently to shared pools on a
single load balancer) to accommodate with requirements got from upstream
customers under the circumstances that load balancer itself becomes the
performance bottleneck, which is critical in integrating Skynet into service flex-up
automation process.
• Designed and implemented Bare Metal Daemon(BAMD) application for agnostic
bare metal provisioning/de-provisioning service for multiple vendors(Supermicro,
Dell, HP and Lenovo) and SKUs which servers for 55K+ assets in PROD to enable
automation in setting up new asset or repurposing any existing asset to ready-to-use
state.
• And etc...

Software Development Engineer II
Kaseya · Full-time
May 2016 - Sep 2018
• 2 yrs 5 mos• Working under Agile Scrum by attending daily Scrum meeting for process tracking and reporting, and Sprint planning for requirement gathering and planning.
• Mainly in charge of implementation of back-end SOAP and REST web services for new Polymer Views to replace the old Struts action classes and JSP pages which includes the modules like Bulk Admin, Department, User, Discovery, Reports, User Preference and Global Config.
• Redesigned Discovery model to fix multiple critical bugs and multi-threading problems and optimized the actual discovery process to make the engine recoverable from failures and errors could be properly handled and returned to users. Migrated discovery related data from file system to MySQL database, which includes analyzed, designed and implemented the new database schema all by myself.
• Integrated VSA with Traverse by fetching corresponding Assets info based on the Devices we have in Traverse from VSA to implement Service Desk and Live Connect that authenticated through OAuth.
• Fully responsible and independently implemented Automation Profile module which is for test provisioning automation purpose based on Automation Rules and Actions.
• Designed and implemented Graph Traverse algorithms (DFS based) to rebuild topology map from discovered devices and perform automatic topology connection updating in one pass including building indirectly topology connections in time complexity O(|V| + |E|).
• Led Traverse team on one of MVPs to integrate the Kaseya Traverse with Kaseya VSA which has the highest priority in the company including analyzing and breaking down stories, assigning tasks to team members, managing and monitoring development progress, coordinate between two teams, designing database schema, DAO layer, REST endpoints, core synchronization tasks and giving demo to higher managers weekly.

Programmer Analyst
Marlabs Inc. · Full-time
Jan 2016 - Dec 2016
• 1 yr• Accepted training of Java/J2EE back-end oriented development and outsourced as contractor to clients.
• Solid experience and understanding on SDLC models such as Agile Scrum Methodologies and Waterfall.
• Designed and developed back-end modules with several design patterns such as DAO, Singleton, MVC and Factory patterns.
• Used Spring framework as business logic tier to perform IOC, AOP and integration with Spring MVC.
• Used Struts to implement MVC by implement corresponding action classes and JSP pages.
• Performed ORM with Hibernate to design and create the mapping classes, sessions, transactions, HQL and Criteria to fetch data from relational database such as MySQL and Oracle.
• Analyzed, designed and implemented SOAP and REST web services including DAO, DAOimpl to perform CRUD operations interactive with persistent databases.
• Responsible for analyzing, designing and creating database schema for new features or models that includes writing tables creation and conversion scripts and stored procedures in SQL.
• Used ActiveMQ to implement JMS to make modules in different contexts to communicate with each other.
• Involved in client-side web development and bug fixing using HTML, CSS, JavaScript, JQuery,
AJAX, JSON and XML.
• Extensive experience in writing Unit Testing with JUnit, JMock, Mockito and JMockit.
• Experienced in utilizing Git and Stash for version control and Jira for bug/issue tracking.