Simic Zhang, Developer in Shanghai, China
Simic is available for hire
Hire Simic

Simic Zhang

Verified Expert  in Engineering

Slackbot Developer

Location
Shanghai, China
Toptal Member Since
September 18, 2019

For over the past decade, Simic has been making a living as a Java developer. He has a robust knowledge base of UI development and most Java and JavaScript frameworks such as Spring, Hibernate, JPA, Log4j, jQuery, React, and so on. Where Simic really shines is his ability to solve performance issues resulting in him often becoming the go-to guy on his team when working on a project.

Portfolio

Cisco
RabbitMQ, Cassandra, InfluxDB, Jenkins, Spring Boot, JavaScript, C++, Java
SAP
Domain-specific Languages (DSLs), SonarQube, CSS, HTML, JavaScript, Java

Experience

Availability

Part-time

Preferred Environment

Jenkins, Git, IntelliJ IDEA, Eclipse, MacOS

The most amazing...

...thing I've coded is an algorithm to parse a math expression into a binary tree which is then sorted according to its respective math operation precedence.

Work Experience

Tech Leader

2017 - PRESENT
Cisco
  • Developed and maintained several microservices using Spring Boot, Cassandra, Reddit, and RabbitMQ.
  • Applied several performance enhancements and increased throughput during business peak time.
  • Created a new pipeline so all developers could work on the master branch and perform deployment by creating a release branch.
  • Designed and implemented a variety of metrics and alerts with InfluxDB, Grafana, Kibana, and AppDynamics to track health status and performance of microservices.
  • Developed an integration test framework by using embedded Cassandra, Reddit, and RabbitMQ. This framework made it easy to run end-to-end tests inside one JVM.
  • Performed a stress test using JMeter and measured the application capacity by running a JMeter script in 500 processes on 12 machines.
Technologies: RabbitMQ, Cassandra, InfluxDB, Jenkins, Spring Boot, JavaScript, C++, Java

Principle Engineer

2012 - 2017
SAP
  • Led a team in the development and maintained a business rule engine.
  • Initiated the idea and implemented a web application called Code Search; this app allowed software engineers to search their code in a Subversion server and won a company award that year.
  • Initiated the idea and completed the challenging task to upgrade all the existing complex database rules to lightweight DSL rules in high quality (with only two minor bugs reported after the new rule format was applied).
  • Developed an integration test framework which simulates the J2EE container (EJB, database, SEAM, and so on) in a local JVM so developers didn't have to wait minutes to restart the application server to verify functions for each code change.
  • Built an automatic code migrator to update logging related code from Log4j to Log4j 2 for thousands of Java classes.
Technologies: Domain-specific Languages (DSLs), SonarQube, CSS, HTML, JavaScript, Java

Generic Annotation Scanner | GAS

http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.htm&r=1&f=G&l=50&s1=9,575,750.PN.&OS=PN/9,575,750&RS=PN/9,575,750
I implemented a fast algorithm to find Java classes with a specific annotation—this single change improved the server startup time from ten minutes to 1.5 minutes.

Languages

Java, JavaScript, HTML, CSS, C++, Groovy, Domain-specific Languages (DSLs)

Tools

Apache Maven, Apache JMeter, RabbitMQ, Jenkins, AppDynamics, Slack, HSQLDB, Microsoft Teams, Grafana, Kibana, IntelliJ IDEA, Git, SonarQube

Paradigms

Test-driven Development (TDD), Agile

Platforms

Oracle, Windows, MacOS, Eclipse

Storage

Cassandra, InfluxDB

Other

Microsoft Graph API, OData, Slack App, Slackbot

Frameworks

Spring Boot, Express.js, Material UI, Ant Design

Libraries/APIs

jQuery, React, Backbone.js

2008 - 2011

Master of Engineering Degree in Computer Science

Shanghai Jiao Tong University - Shanghai, China

2000 - 2004

Bachelor of Engineering Degree in Computer Science

Shanghai Jiao Tong University - Shanghai, China

Collaboration That Works

How to Work with Toptal

Toptal matches you directly with global industry experts from our network in hours—not weeks or months.

1

Share your needs

Discuss your requirements and refine your scope in a call with a Toptal domain expert.
2

Choose your talent

Get a short list of expertly matched talent within 24 hours to review, interview, and choose from.
3

Start your risk-free talent trial

Work with your chosen talent on a trial basis for up to two weeks. Pay only if you decide to hire them.

Top talent is in high demand.

Start hiring