Inside the public health unit in Auckland phones are the country's best defence.
With months - maybe years - until a COVID vaccine, contact tracing is key to containment - finding and isolating every Kiwi exposed to the virus before it can spread.
"Gold-standard testing, case isolation and contact tracing is going to be the system that protects the public until we get a vaccine," epidemiologist Ayesha Verrall told Newshub Nation.
The greater freedoms of alert level 2 will test if the system is up to scratch. An audit by Verrall in April found contact tracing was overwhelmed. New Zealand needed three to four times the workforce to prepare for up to 1000 cases a day.
Dr Verrall says despite good progress, New Zealand's contact tracing is not there yet.
"The Government should be able to reassure us we're able to hit that target before we move to level 2.
"I'm really optimistic they're on track to do that. And yes, I think we need to hit that target before we move down a level."
The Government has promised 300 more staff to meet Dr Verrall's recommendations in 12 public health units nationwide. But after several inquiries from Newshub Nation, the Ministry of Health still won't say how many have started or when they'll be done.
Julia Peters, Auckland Regional Public Health Service clinical director, says Auckland's public health unit is scaling up quickly.
"Over the last couple of months we doubled our medical workforce and trebled our nursing workforce."
In an outbreak they'd be needed fast. Dr Peters says while such a large team isn't needed while case numbers are low, they need to be ready to move quickly.
"At the moment we're seeing fewer cases, so we don't need such a large workforce, but we do need to be able to flex up and down at short notice and that's part of our planning as we get through the rest of this year,"
The system was severely tested in Auckland at Marist College, where one of the country's biggest clusters emerged. It's still not known how the cluster started, but 95 cases quickly ensued.
The latest - a student - was confirmed only on Wednesday, six weeks after the first case was found. Dr Peters acknowledges mistakes may have been made.
"We know that there were some issues with contact tracing and symptom checking in the early part of the response."
The student received a contact tracing call a month ago but had no symptoms and it wasn't followed up. Lessons have been learned since those first weeks in April and now close contacts get calls every day.
"The ideal is that people are contacted every day and their symptoms are checked in person," DrPeters says.
The goal is to isolate 80 percent of those exposed to a COVID-19 patient within four days of them getting sick.
It was taking 10 days in the middle of April. Now that number's reduced to five - close, but not quite the four-day gold standard. And the task is easy with the country in lockdown - at alert level 2, bubbles will burst.
"What we expect when we go into level 2 is that people's lives will once again become more busy, more complex and consequently, if we do see cases, they're very likely to have more close contacts," says Dr Peters.
Dr Verral says early identification of the virus will be key at level 2.
"The thing the ministry needs to focus on for the next week is encouraging New Zealanders to get tested early, and that will drive that time down."
Some believe massive investment is needed to match public health efforts overseas. Even after extra investment, Australia's 7000 contact tracers will be double the number per capita here.
Epidemiologist Sir David Skegg says we need to follow Australia's lead.
"The system for rapid tracing and isolation of contacts must be upgraded urgently so that we can achieve the same performance as the Australians."
Australia's called in the army for tracing, aided by Bluetooth smartphone tracking. A 'COVID safe' app lets people know quickly if someone they've had contact with has tested positive for the coronavirus. It's now been downloaded more than 5 million times.
Pro Bruce Thomson from Swinburne University of Technology in Melbourne says measures like the app are an important part of keeping people safe while leaving lockdown.
"The Government is basically saying if we want to really actively start decreasing our social restrictions, we need to have some other form of tracking, and it makes sense."
But hopes for a Bluetooth app in New Zealand have been played down in recent weeks. And if our contact tracing doesn't match Australia, Prof Thomson says a trans-Tasman bubble could have to wait.
"We need to have a lot of similarities before you'd start actually allowing each other to transfer freely between countries."
Back in New Zealand, Dr Verrall agrees.
"It may well be the Australians say, 'for this to be OK you need to double your contact tracing'."
In the meantime only days remain to prepare for a move to alert level 2, but Verrall says she's "optimistic".
"I know how much we've improved across the last 2 weeks, and if we continue to keep that up we should be able to go down to level 2, we should expect that they should be ready for that."
Cabinet will decide if we're ready on Monday. If we leave lockdown, stakes are high. Countries like Singapore saw big outbreaks after experiencing early success.
Move too quickly without gold-standard tracing, and six weeks of sacrifice could be wasted.