Originally from Cavan, but now teaching in Dublin, he has created SubEd Ireland, a platform connecting verified teachers and special needs assistants (SNAs) quickly with schools,  inspired by his time in Australia.

Spending 10 weeks waiting for his Irish teaching papers to be transferred and certified by the authorities there, he came across platforms designed to put substitute teachers in touch with schools quickly and efficiently.

It struck me immediately, why does nothing like this exist in Ireland? Back home, principals are ringing around at 7am in a panic, teachers are waiting by the phone and classrooms are being left empty or split across other classes. It seemed completely unnecessary.

SubEd Ireland is now live, with teachers and principals signed up across Dublin, Cork, Donegal, Cavan, Meath and Leitrim. It is aiming for a full national roll-out come September.

Schools in both cities and rural areas regularly face challenges when it comes to securing substitute cover for the hard-to-plan-for unexpected absences, such a sickness or illness in the family. 

In 2019, the Department of Education began establishing supply panels, with a pilot established across six areas. Supply panels see schools clustered into geographical areas, with supply teacher posts allocated to this group of schools.

These supply teachers work across the group of clustered schools, providing fixed-term cover of up to a fortnight. Last month, education minister Hildegarde Naughton said there were now almost 170 supply panel clusters across the country, consisting of 587 teaching posts providing substitute cover in 2,905 schools.

But gaps still persist. During the 2024/25 school year, substitute teachers covered at least one million school days in Irish schools. Figures previously released by the Department of Education show 796,665 days were covered by substitute teachers at primary level.

The true number of days is likely to be even higher again, as short-term leave is recorded locally by schools and not by the department. These figures also do not include the number of days covered by the substitute teacher supply panels.

Difficulties in sourcing substitute cover for absences in primary schools disproportionately affects special education, schools in disadvantaged areas and Irish-medium education.

A survey published by the Irish National Teachers Orgnisation (INTO) last October found some 60% of more than 560 schools had been unable to source a substitute for an absence.

The practice of ‘splitting’ classes to cover for absent colleagues is “widespread”, the INTO found. More than a third of the survey schools reported splitting classes, resulting in 735 days of disruption to learning during the first six weeks of the current school year. 

A further 65% of schools said they had to redeploy a special education teacher to cover for the absence of a class teacher.

Given the scale of the challenge when faced with securing substitute cover last minute, many principals rely on putting a call out through WhatsApp groups, Mr O’Reilly explained.

He established groups himself, in a bid to give substitute teachers a community where they could directly connect with schools.

While these groups have their benefits, they also have their downfalls. “Right now, the way most Irish primary schools find subs is through a patchwork of unverified WhatsApp groups, personal contacts and last-minute panic,” he said.

The WhatsApp groups are capped at around 1,200 members. After that, the admins have to create a new group. At one point, there were seven full WhatsApp groups in Dublin alone.

"So, principals are just posting the same call out into the next WhatsApp group, and the next WhatsApp group. It's a lot of work for the admin and a lot of work for the principals who are just copying the message into each group or forwarding them on and then replying to every person who got back to them to say, ‘the position is filled’.” 

Principals also have no way of knowing about a substitute teacher’s profile. They might give the position to a student in the second year of their studies, to be contacted 10 minutes later by a retired principal or a teacher with five years' experience who may be better suited to the class.

There is another big downfall to the WhatApp groups: security and privacy.

“With the SubEd Ireland platform, the principal’s personal phone number is not being released or broadcasted. Principals are currently wasting hours every week with phone calls trying to fill positions. 

"The messages might get buried in busy group chats as well. Some people might be gone to Australia, or they are going to Canada or Dubai and they are still in these WhatsApp groups. They are full to the brim. Dublin currently has eight WhatsApp groups, and seven of them are full, with 1,200 members. There could be 400 principals in each WhatsApp and the rest are subs.” 

He said there were thousands of members and teachers’ personal contact details exposed to strangers, and scammers have infiltrated the groups.

This includes investment scams, where fraudsters have created fake investment-related groups, joined the group and sought sign-ups through links for a “discussion group” about stocks.

“I’m trying to fix this, make a secure platform and have it Irish-built,” Mr O’Reilly said.

"It’s a bridge. The substitutes and the SNAs will be able to sign up and have their own information on their own profile, but it's still a connection for a principal. The principal will still get their documents and make sure to triple check they are verified themselves. 

But it saves a lot of time, and its means not releasing the principals' personal details, meaning they are not exposed.”