Don't be a hero

However, it's not always the business owner's fault for making unreasonable demands; the developer who commits to those demands is equally at fault.

Remember, it is the business owner's, or your manager's, role to get as much out of you as possible. But more importantly, it is your duty to inform them of what is and isn't possible; so, when asked to complete features under a deadline that you cannot meet without sacrificing on quality, do not accept the deadline.

You may think the business would appreciate you for going the extra mile and making the impossible possible, but there are four problems with this line of thinking:

1. You may not actually complete the feature in time, while the business has planned a strategy that depends on that deadline being met.
2. You've demonstrated to the manager that you're willing to accept these deadlines, so they may set even tighter deadlines next time, even if they don't need to.
3. Rushing through code will likely incur technical debt.
4. Your fellow developers may resent you, since they may have to work overtime in order to keep up with your pace; otherwise, their manager may view them as slow. It also means they'll have to develop on top of your rushed code, making everyday work less enjoyable.

There's a time to stick your head out to save a business, but by doing it too often, you are actually hurting the team. The danger is that neither you nor the business owner will realize this; in fact, you may even na?vely celebrate the rapid progress being made.

The solution here is to manage your business owner's expectations. If you believe there's a 50% chance of meeting an optimistic deadline, then ask for the scope to be reduced further until you can be more confident in your estimate. Speaking from experience, business owners would rather hear it's not possible a month in advance than a promise of everything will be done that was not delivered.