You are a contractor, not an employee
You are engaged to deliver an outcome, not to be supervised hour by hour. Nobody tracks your hours, nobody watches your screen, and there is no timesheet to fill in.
That is a real freedom and it carries a real responsibility. You run your own affairs: your own registration where you live, your own tax, your own records. VERTX is your contracting party, not your employer, and it operates no payroll.
You never chase money, and you never negotiate it
The client pays for the work. VERTX sits in the middle and does the administration: the invoice is prepared and issued in your name, so you never raise one, and you never invoice a client, chase a client, or discuss money with one at any point.
Your rate is set against the level you are assessed at during vetting, agreed before you start and written into your contract. It does not move because a client pushes, and it is not something you are expected to defend.
Discussing your rate with a client is a material breach of the agreement you sign, so it is worth knowing before you meet one rather than after.
What to sort out before your first engagement
Two things are worth doing early, because they are the usual causes of a slow start. The first is whatever local registration lets you invoice a foreign company as an individual, which in most countries is a straightforward self-employed or sole-trader setup under whatever it is called locally.
The second is a bank account in your own name that can receive an international transfer. It must be your own account. We cannot pay a third party, a family member's account or a company you do not control.
Start both before you are placed rather than after. Neither is difficult, and both take longer than people expect.
Tax is yours, and the records are ours
You are an independent contractor, so tax where you live is your responsibility. Rules differ enormously by country and we are not qualified to advise on yours.
What we do give you is a clean record: an invoice for every payment and a statement you can hand to an accountant without having to reconstruct anything from your own notes.
Four questions to ask an accountant before you start
What registration do I need locally to invoice a foreign company as an individual?
How should I record income received in a foreign currency, and at what rate?
What do I need to set aside, and when is it due?
Is there anything about receiving an international transfer into a local account I should know before it arrives?
Ask these at the start rather than a year in. It is a short conversation now and an awkward one later.