Debbie Crosbie will join the challenger bank from Clydesdale Yorkshire Banking Group (CYBG), ending her tenure of 20 years at the financial services firm where she now resides as chief operating officer.
However, he clung on until September, only leaving after yet another outage left infuriated customers without mobile, online or phone services for nearly two days.
She will also be eligible for a bonus scheme similar to Mr Pester's, the detail of which will be in its annual report.
In a canned statement that must have slipped through the PR team's irony filters, Crosbie, who will join TSB in 2019, praised the culture at the bank and its "passion" to "deliver for customers". With over two decades of experience, superb retail and SME banking expertise, and a genuinely open and engaging style of leadership, we have found an outstanding new chief executive.
He added: "Debbie's appointment is another step forward against the three priorities we set out in September, namely: completing the work of putting things right for customers; achieving full functionality across all TSB products and services; and appointing the right CEO for the next chapter of TSB". At that point he will return to his previous position as non-executive chairman.
The bank bosses thought they could save £160m a year by moving to a new platform designed by TSB's parent company Sabadell - but after the failure, questions were raised about the testing that had been carried out.
It has suffered further IT issues since then, and was forced to apologise again in September after many customers were once more left unable to access their accounts. The problems continued for many weeks and TSB came under fierce criticism for the IT failings.
TSB has hired a banking veteran as its new chief executive, bringing its months-long search for the role to a close. He had joined Lloyds Banking Group in 2010 and in 2011 had been appointed to lead the launch of TSB and its separation from Lloyds.