This sound very familiar, the software development company I work for uses at least 10 different platforms internally across Linux, Windows & Unix...SQL server,

This sound very familiar, the software development company I work for uses at least 10 different platforms internally across Linux, Windows & Unix...SQL server, mysql & oracle dbs. 10yr old PHP customer support systems, 8 yr old jboss & tomcat servers with deserialization vulnerabilities at every turn, .NET V3 testing tools, mixed up with a sprinkling of modern platforms all talking to each other through rest, direct DB connections, microservices & a hearty dose of black magic. Management ignores vulnerability reports due to mostly non-technical backgrounds. Most documentation is at least 3yrs old, when 80% of dev team sacked & outsourced to India. Mostly keeping the lights on now during an acquisition...can't wait to debrief the new owners. Have acquired some great experience in investigating technical debt in the process which will hopefully be useful in the future.