Core java, Collections, Multi-threading, Exception Handling and concurrency,
Solace or JMS, Spring: Dependency Injection only, design patterns ,
JVM Performance Tuning – JMC, jconsole, jvisualvm, Java Flight Recorder, Yourkit or any other tool, should have understanding of GC and thread statistics.
Build: Maven, Jenkins, Nexus, Github – basic knowledge
Capital Markets experience is highly desired.

Good to have:
Scripting: Linux, basic commands on files, logs monitoring.
Database: Basic SQL Queries
Scheduling: Ideal to have understanding of any scheduler: Geneos, Ctrl M or anything else.

Non-Technical:

Good Communication Skills, be able to relay information effectively.
Willingness to learn, as the platform is vast.
Analytical Mind/Sharpness as it is a front office application and sometimes requires acumen to solve domain related problems.