Crystal Lu

• Part of the DevOps team and provided subject matter expert support to various application teams.
• Led the MongoDB projects including design/build/maintenance of MongoDB replication, sharding and MongoDB Atlas.
• Performed root cause analysis and corrective actions of MongoDB issues. Worked closely with developers and provided SME support related to the MongoDB environment during the software development Lifecycle.
• Maintained and monitored databases to ensure high availability, load balancing.
• Monitored system resources including CPU usage, memory utilization and disk space usage to optimize system performance.
• Fine tuned MongoDB slow queries using data structure optimization, proper indexing and index housekeeping.
• Optimized system performance by adjusting system configuration, traffic rerouting, adequate resource allocation and scaling.
• Wrote MQL queries utilizing MongoDB aggregation framework to pull business reports.
• Automated DBA routine tasks and business report generation by scripting/programming using Python, Javascript, Ansible, Jenkins and Terraform.
• Proactively evaluated and improved HA and DR solutions, as well as monitoring and alerting.
• Hands-on experience with AWS services, such as RDS, EC2, EBS, network, systems manager…
• Sucessfully upgraded hundreds of databases for MongoDB, Aurora MySQL and MariaDB.
• Participated in daily Scrum meetings and collaborated with teams using Jira and Confluence.
• Support on-call 24x7 rotation for any critical production outages and keep things running smoothly on all fronts.

Led and supported multiple projects for OLTP and OLAP applications using Oracle, MongoDB, PostgreSQL and MySQL in the Data Protection Technology Department.

• Supported business applications, ensuring system scalability, security, performance, and reliability.
• Built the database infrastructure from the ground zero following the best practice.
• Maintained, supported and optimized database ecosystem.
• Ensured compliance with all applicable laws relating to data privacy, storage and use of information assets.
• Evaluated system performance against established benchmarks to identify areas of improvement.
• Monitored system resources including CPU usage, memory utilization and disk space usage to optimize system performance.
• Actively drove feature enhancements, permanently resolved the root causes of issues, and improved the performance of our managed database service.
• Managed users, roles, profiles and audit requirements across multiple databases according to security policies set forth by the organization.
• Configured and maintained database security features, including data encryption, audit, user and role management.
• Collaborated with development teams on application design decisions that affect the underlying database structure.
• Elevated documentation processes for database configurations, procedures, and best practices for knowledge sharing among team members.
• Stay current with industry trends and source new ways to improve database systems.
• Provide 24x7 on call DBA support for production environment on rotation schedule and ad hoc need basis.

Oracle

• Installed Oracle RAC, ASM, Data Guard and OEM to support one of the top 10 projects in the bank on a tight timeframe and achieved 100% uptime.
• Configured replication of multiple databases using Oracle GoldenGate replication technology.
• Implemented backup strategies for disaster recovery scenarios utilizing RMAN toolsets.
• Setup Oracle Wallet TDE for data security of RAC databases.
• Migrated databases and application data using various methods including data pump, RMAN, and zero downtime migration service.
• Designed, developed, tested and deployed stored procedures, functions and packages in Oracle PL/SQL involving complex data analysis and data manipulation.
• Performed Oracle table partitioning and quarterly maintenance work.
• Wrote scripts in Java, Python and bash to assist the development team by adding extra functionality to applications and automating DBA tasks.
• Resolved deadlocks or other concurrency related issues in order to improve overall system throughput.
• Designed and developed scripts for loading and analyzing large datasets from text files.

MongoDB

• Volunteered to take over the responsibility to support a new project using MongoDB technology.
• Setup MongoDB replicaSets on a limited deadline and later performed a horizontal scaling using the collection sharding.
• Installed and configured Ops Manager to automate database backup, monitoring and ease DBA tasks.
• Diagnosed and optimized slow queries and system performance.
• Enabled encryption and authentication using SSL certificates to secure database communication.
• Collaborated with the dev team to build better application schema and recommended changes towards the data and index structures to improve query performance.
• Migrated databases to the cloud using MongoDB Atlas for better management.

PostgreSQL & MySQL

• Installed, upgraded and maintained PostgreSQL and MySQL databases.
• Built PostgreSQL cluster for high availability, load balancing and replication using streaming replication.
• Setup PostgreSQL backup and restore strategies by making a base backup and continuous archiving.
• Built Percona XtraDB cluster to set up multiple MySQL master databases for two-way communication to enhance performance.
• Setup monitoring of PostgreSQL and MySQL environment using Datadog, Percona.