Common project risks:
The first thing you should do when working on a project is deploy. Then you know that you can do it with the existing code.
The second thing you should do when working on a project is to write a stub of what you are doing, prove that it doesn't cause a regression (wrap it in a beta-flag if need be), and then deploy.
Here's what usually happens: You wait until the end of the project to deploy. Then you realize that you can't deploy, because you need a new database or because your deploy script doesn't work or because this is a new service that has never been deployed before and you simply don't know how. So you start working on deploying it into a staging environment. But then you have to go around and build a staging environment and get all of your stuff working there. Then you test. But you STILL can't deploy to production, and you don't know how long it will take. So finally you get your prod stuff set up and deploy, 2 weeks after you intended to be done with the project.
So let's flip this. Work out how to deploy null code, zero changes, into prod. If there is no real code, there can be no real errors, so you don't need to put it into staging first. Next put it into staging, since you'll need that in the future. Now you know exactly how much labor it will take to get your thing into production - none.
This stacks up a severe unknown right at the end.
Putting something in prod immediately might seem scary, but really this strategy has the least and most isolated risk. Put your empty code behind a feature flag or if safe and non-contradicting put it on a new page that isn't linked.
A typical project implements a new workflow, usually with several steps or across a few systems. We take the project and break it into features with each feature feeding data into the next. Then we sort based on the data flow and begin implementing features.
Imagine we were trying to add a new feature to our eCommerce site so that people can submit issues with an order. So here we would say "ok! Let's start by building a Create-Claim UI on our site!". We break that into a few tickets and go to work! Once we have that working pretty well we move on to Transmitting, Processing, etc.
There are a lot of things we might run into in this workflow:
One approach that some people take to help with these issues is complete up-front design. You think out every bit of the thing, every interface and API and variable and column, and work them all out ahead of time. While appealing, this has issues too - namely that when you go to write the code you have some situational awareness that cannot be obtained beforehand.
So let's try another strategy. Let's try to get the end-to-end flow working, breadth-first style, and then go from there.
Stub out all the "useful" work code and get this working end-to-end as the first task. For example, instead of letting the user create a complete claim, ask them for a single item or just hard-wire it to the last-most item available without any user input. Don't validate or handle errors on transmitting or even handle different products - make a hand-built json string to transmit if you can. And so on. Use Deploy First Development techniques to put your completely wrong but harmless code into production (behind a feature-flag or permission).
Depending on the complexity of the project, a second breadth-first pass might be a good idea - one that doesn't use any hard-coded values for example. Your goal is to get the project to be minimally-useful. Once the project is minimally-useful, every change after that will make it more-useful!
Once you have the end-to-end flow working, and ideally have some testing methodology worked out (either automated or by-hand), then you can switch into a more depth-first technique. You keep factoring out any hard-coded values until you get the whole project organized and feature-full. If you have been deploying the whole time there are no surprises - it isn't a matter of releasing the project, but instead of granting a wider set of people access to an already-working system.