"At first I thought people were just busy and that I'd get to know everyone in time, but it hasn't happened and I think a lot of it comes down to the fact that there weren't many proper introductions at the beginning, no team lunch or anything like that, as well as the office layout — I'm seated away from most of my colleagues so conversations don't happen naturally," she said.
"I'm usually a pretty resilient person but to be honest, there's been times I've cried in the toilets.
"I don't think people have been deliberately nasty but it was such an unwelcoming environment from the beginning. I still feel like an outsider months later."
Katie said she was so unhappy with her job she was considering leaving.
Jason Ajai, principal partner at Sydney recruitment firm Talent Web, said on-boarding mistakes had a huge impact on a new starter's wellbeing and could end up costing a business a fortune.
He said some of the most common mistakes businesses made were leaving new hires to wait for long periods in reception on day one and a failure to introduce the new employee to colleagues and offer adequate guidance and support.
He said new hires often reported a lack of equipment and company merchandise and a clean, prepared desk for them to sit at, no computer or general technology access issues as well as discovering the role was dramatically different to what they expected — a situation that caused most starters to simply leave.
"I'd like to say most organisations get it right, but the truth is they don't," he said.
"Organisations put tens of thousands of dollars into every new hire and when they leave within the first six months and they have to start the process again it is very costly, and it does the brand's reputation no good.
"The impact on the employee is massive. Settling into a new role is one of the biggest things you can deal with along with marriages, mortgages and death — so when you start out in a new role in a new organisation and you find out in the first few days you've probably made a huge mistake, sleepless nights are just the beginning.
"It can affect your relationship with your partner, it can be really embarrassing — there's a whole range of emotions."
Mr Ajai said employees who were having problems should raise their concerns with their manager calmly and confidently early on, and that they should approach the conversation with a "solutions-mindset".
But he added that businesses just needed to put in a little bit of planning to avoid the problem altogether.
"The best advice is to plan and prepare — make sure the person's PC and desk is set up, make sure they have access codes, make sure people are available to meet them in their first few weeks, tap them on the shoulder and let them know you're pleased to have them and they're doing a good job, and set up introductions and meetings for them," he said.
"It's not revolutionary but so many organisations completely miss the mark."
* Name has been changed to protect identity.