Interesting issue with an integration between a new Salesforce application and a legacy enterprise application. The data from salesforce API was limited to 50 records at once so as a workaround the Salesforce team gave access via a SQL call which could send more records each time. Consuming the data came via GuzzleHTTP which absorbed the data from Salesforce and delivers as an object as a nested associative array. E.g.

A Global-scale, financial-services company adopted MySQL for their internal user application DB and needed real-time replication setup across 5+ systems. Pulled in as a 3rd party integrator to setup and load test.

Client had a mobile testing application that was experiencing performance issues and customer support issues at scale. Technology used to create the ap was a NoSQL (MongoDB 3.0), python, JavaScript application. Investigation identified numerous issues including latency in returned data from MongoDB caused by non-sequential needs for data, security issues, and latency in implementation needing to deploy entire dataset to mobile device. Hired and led team to re-work mobile ap as a web-based implementation which only required a small subset of the data to be transferred to the mobile device.

2016: Infrastructure as a Service (IAAS) and Application Architecture:

Client requested upgrade of a legacy system for an organization that engages potential voters in U.S. elections across dozens of campaigns. Migrated to a full virtualized IAAS microservices architecture with virtual firewalls, virtual LANs, and virtual DEV/TEST/PROD servers. Negotiated contract for service, did load testing to predict needed allocation of resources, and led team for a successful roll-out, and hosted solution.

Originally setup in MySQL and moved to MariaDB

Client had a Drupal7 site that had the (not yet discovered) bug in that version of Drupal where the views cache was being rebuilt for anonymous users accessing the front page.

While the root cause could be covered up with proxy/cache servers an ultimate solution needed to be found.

One test was to see if replacing MySQL with MariaDB increased speed. It did.  Because the cache was broken in that version of Drupal it was causing excessive DB lookups. Changing from MySQL to MariaDB resulted in a 2x to 7x performance improvement.

Customer had a Java/Tomcat/Apache/MySQL application that was unable to absorb real-time GPS probe point data from millions of vehicles without choking. Vendor sending the real-time GPS data would get errors and stop the feed.  Lead programmer for application insisted that the only way to fix the issue was to "upgrade to 'Enterprise class' software like WebSphere and Oracle" 

A client in a secured government facility used a custom Paradox application to manage employees, track hours, parts, labor, and generate invoices. The hardware on which the program existed was failing and other contractors had been unable to migrate it to a new system.

The client was required to change the program logic for how it calculated invoices, however the company which developed the application no longer had the developer on staff, no longer had the source code for the "delivered" (binary only) sections, and did not have the administrative password.

2004

2002: Hired by a Fortune 100 client looking to purchase a company and product that offered commercial, enterprise-level , web-based system for project development/management. The company asked me to do a non-destructive security analysis on a production system.

Organization using Peoplesoft on Oracle wanted to have an online application which tracked employee assets in a complex way that Peoplesoft did not offer. Existing corporate web server did not offer native OCI calls, just slower generic ODBC modules.