There is a wide mix of expertise within the team at ITSS to ensure that we have the knowledge to provide complete end to end software solutions in the financial space. The team consists of  tax consultants, software developers, business analysis’s, test engineers, UAT specialists and customer services personnel.

John Twomey

Managing Director

I co-founded the company in 2008 with Finbarr & Orla. Together we strive to provide first class products and services. I head up training and sales of the tax software and most likely will be the one you will meet at one of these events.

Finbarr O Connor


Hey! I analyse and specify the legislative changes to ensure the software is continuously up to date. If you’re looking to challenge our opinion on Tax legislation then I will be the one to deal with your query

Orla O Shea


If you are considering a project or wondering how to streamline a process within your firm, then talk to me. While we are tax experts first, we also work on many other projects, from software integration, rewrites of legacy software to simple applications to help streamline processes within your firm.

Paul Flynn

Software Developer

I’m the guy who heads up development on the Personal & Corporation tax software. I have worked on the tax products for almost 10 years. As an unintended consequence I have built up 10 years of tax software knowledge along with understanding of the needs of accountants and tax advisors, this allows me to adapt the software quickly to meet the needs of the user.

Eoin Prout

Software Developer

Leading the development on new projects, I have extensive experience in green field as well as legacy software development. I initially started working on tax compliance software back in 1999 and since then have gained in-depth knowledge across various sectors.

Mark O Sullivan

Software Developer

With many years software development experience in the UK, I joined ITSS in 2011. While I work on various projects my expertise lies in ixbrl and web-services.

Airton Esmerio

Software Developer

While living in Brazil I developed and regionalised financial software. Since moving to Ireland, I have worked with ITSS on various projects for the accountancy sector.

Jader Mederios

Software Developer

After 15 years working as software developer this is the dream team.” I moved to ITSS from Brazil and I involved in the development of phone apps for clients.

Jola Marcinowska

Senior Test Engineer

So, I am the woman who keeps the developers in check. With extensive experience (15+ yrs) of testing financial software for the Polish Revenue Commissioners, I ensure the software you get is top class.

Flora Weiler

Test Engineer / User Acceptance Testing

My role covers UAT and testing on the products. As well as accuracy I also ensure that you will have the best user experience.

John McElheron

UK Compliance Analyst

As a UK tax specialist and Business analyst, I joined ITSS in 2015 following a long stint with HMRC in the UK.

Micheal O Brien

Customer Services

I’m Micheal, I am sure I have spoken to many of you over the years. I cover the phone and email support for the the Personal and Corporation tax products. If you need any help, I am more than willing to take your call and assist.