More than one in ten children under the care of Tusla do not have their own social worker, an Oireachtas committee has heard.
Around 2,400 children - 12% of the 20,000 open cases - have not been given a dedicated social worker.
The Public Accounts Committee heard that this does not mean that they are not being provided with a service.
Kate Duggan, Director of Services and Integration, acknowledged that Tusla has a lower proportion of social workers than our European and UK neighbours.
A shortage of social workers nationally remains a significant challenge, she said.
Committee Chair, Sinn Féin Deputy Brian Stanley, noted that Tusla's 1,170 social workers face a "fairly hefty workload".
Each worker is handling around 65 cases; "ideally" their numbers should be doubled, he said.
Tusla offered each of this year's 184 graduates in this field a permanent job.
And while 99 of them were recruited, 89 social workers left the service in the first half of this year.
Ms Duggan said that a further 70 social workers are on maternity leave.
With Covid restrictions, they are off the front line for the entirety of the pregnancy.
She said that there is also a move to diversify Tusla's teams, using other skill sets to meet needs.
Tusla operates at 300 locations across the country, and 120 front line posts were created this year.
Bernard Gloster, Tusla CEO, said the agency dealt with 70,000 referrals last year.
A "concerning decrease" in referrals when the pandemic hit was addressed and numbers then recovered, he said.
But he flagged a troubling and increasing dependence on temporary staffing.
"More than 60% of our children in residential care [are] now dependent on private provision," Mr Gloster told the committee.
"That is far too significant a dependency," he added, and promised to come up with a plan by the end of the year to tackle it.
Sean Sherlock, Labour TD, noted that when private providers leave the market at short notice, the State has to pick up the slack.
While Tusla spent €19 million on agency staff last year, more than 400 agency staff have been made permanent, saving €4m annually.
Mr Gloster also warned that community and voluntary organisations face serious financial challenges.
This makes recruiting staff difficult, and he expressed concern over their long-term future.
In the wake of the cyber attack on the HSE in May, Tusla is now a year ahead of schedule in its migration to an independent ICT system.
That attack "brought us to our knees", the Tusla chief said.
"There was a risk of data exfiltration that might yet emerge," he warned.
And while there are no indications that this occured, "We're a long way off being able to be definitive about that," he concluded.
Sinn Féin's Matt Carthy was told that there are around 5,900 children in foster care, representing 92% of all children in Tusla's care.
Pat Smyth, Tusla's Director of Finance, said that 480 foster children are with private providers.
This is up from 430 in 2019, and costs €23m a year.
A private provider is paid €1,000 a week, out of which they pay the foster carers.
The provider makes a profit of around €200, Mr Smyth said.
Foster carers directly recruited by Tusla receive around €350 a week.
Mr Glouster acknowledged that some have said that they get more support from private providers than from Tusla.
He was not aware of a pattern of foster parents opting out of Tusla and registering with private providers, but said he would look into it.
He also said that a special investigations unit will start operations in January, and this will mean decreasing the outsourcing of that role.
Previously the Comptroller and Auditor General has reported that Tusla breached procurement guidelines on purchases of €6.3m.
This was 3% of the total spend of €228m, and was Covid-related expenditure.
The committee heard that two people have now been tasked with tackling procurement, and this is being increased to five.