Thomas Cashman, Developer in Dublin, Ireland
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Thomas Cashman

Verified Expert  in Engineering

Back-end Developer

Dublin, Ireland
Toptal Member Since
January 10, 2022

Thomas is an expert Java, C#, and JavaScript software engineer and technical architect. He has 10+ years of professional experience working as a developer and technical consultant in various projects and managing agile-based development teams. Thomas is keen on high-reliability and high-performance applications across multiple industries, including telecom, financial, pharma, and entertainment.


Viridian Software
Java, C#, C++11, JVM, QA Leadership, Technical Leadership, Architecture...
Java, C#, Technical Leadership, Technical Architecture, IT Systems Architecture...
SS7, Long-term Evolution (LTE), Java, Spring, JUnit, Git, Linux, Elasticsearch...




Preferred Environment

Windows, Linux, Java, C#, PostgreSQL, Elasticsearch, Spring

The most amazing...

...projects I've built are a Java to C# transpiler and an on-site telecom log indexing system with 9 billion records per day and 1-year retention period.

Work Experience

Technical Director

2018 - PRESENT
Viridian Software
  • Managed a team of engineers dedicated to video game development. As a technical director, I provided mentorship and guidance to the team while also working in the technical architecture design for video game products and tools.
  • Designed and implemented a Java to C# transpiler for video game console platforms to assist the team in their product launch.
  • Designed the development and quality assurance (QA) processes within the company.
Technologies: Java, C#, C++11, JVM, QA Leadership, Technical Leadership, Architecture, Game Development, Game Tools Development, Unity

Technical Consultant

2017 - PRESENT
  • Developed a log indexing system for on-site distributed telecommunications with large-scale requirements—9 billion messages per day and 1-year retention and search time.
  • Developed a blockchain proof of concept application for the EU-based stock exchange.
  • Consulted a pharmaceutical firm on the architecture and development of a new compliance and audit management software to prepare for the acquisition by Pfizer.
Technologies: Java, C#, Technical Leadership, Technical Architecture, IT Systems Architecture, Application Architecture, Web Application Architecture, Gradle, Vue, Apache Maven, Git, GitLab, Spring, Spring Boot, Networking, Amazon Web Services (AWS), Sockets

Senior Software Engineer

2012 - 2017
  • Developed several high-reliability 2G, 3G, and LTE mobile network products, as part of an Agile-based development team, including the Steering of Roaming, Roam Welcome and Anti-Steering of Roaming Detection, SMS Defence and Dialled Digit Correction.
  • Led the web application development for the entire LTE generation of Cellusys’ portfolio of roaming products.
  • Implemented an SS7 message processor for Cellusys’ first Camel-based product, Dialled Digit Correction. It is currently deployed to a live network of over 50 million subscribers.
  • Handled the on-site deployment and customer training for several products.
  • Managed the internal development operations and training for new employees.
Technologies: SS7, Long-term Evolution (LTE), Java, Spring, JUnit, Git, Linux, Elasticsearch, PostgreSQL, Apache Storm, Apache Kafka, Angular, Kibana, Node.js, Technical Leadership, IT Infrastructure, Gradle, Apache Maven, GitLab, Networking, Sockets

Steering of Roaming
The world's first SS7 and LTE hybrid roam steering system. I led the web application development for this and other roaming products from Cellusys' LTE product suite. The application was built by an agile-based development team using a Spring-based back end and Angular front end.

Kava Transpiler

A Java to C# transpiler with full JDK support. It was implemented to help Viridian Software bring their Java-based video games to Xbox, PlayStation, and Nintendo platforms. I was the lead architect and developer on this project. The generated code had to be corrected to replicate both applications, JDK, and third-party library behavior while staying performant for older generation hardware.

SMS Firewall
Worked as the lead developer on SMS Defence—later rebranded as SMS Firewall—version 2.1. The new release added A2P monetization capabilities for existing customers. An essential requirement was no performance and latency loss could occur with the extra functionality. I spent a lot of time benchmarking and optimizing the existing code to stay within the new functionality's latency requirements.
2007 - 2011

Bachelor's Degree in Software Engineering

Dublin City University - Dublin, Ireland


.NET BCL, Vue, Sockets, Node.js


Git, Gradle, MSTest, GitLab, Apache Storm, Kibana, Apache Maven


JUnit, .NET, Spring Boot, Spring, Angular, Unity


Java, C#, C++11


Application Architecture, Web Application Architecture


JVM, Linux, Amazon Web Services (AWS), Windows, Apache Kafka


PostgreSQL, Elasticsearch


Technical Leadership, Technical Architecture, IT Systems Architecture, Architecture, Game Development, Game Tools Development, IT Infrastructure, SS7, Long-term Evolution (LTE), QA Leadership, Networking, Software Development

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