There are many different ways of prioritising tasks. My personal favourite is Weighted Shorted Job First.
By always picking the (weighted) smallest task first you reduce risk and deliver value to the business faster.
In a nutshell, look at all the jobs to do; for each task, estimate the resource investment (no. of people, time) and the price of delaying the task (e.g. decreased revenue). Then divide one by the other, e.g. $100.000 revenue divided by 50 hours, each $100 gives us a value of 20 for an example completely made up task (and salary).
You could also consider including other costs such as SaaS costs, insurance, etc, but simpler is better for the purposes of task prioritisation.
When you do this for all your tasks and sort them by their respective weighted values descending, then you get a prioritised list of how to deliver the most value to your company with the least amount of effort.
My favourite side-effect of WSJF is perfectly illustrated by the comic: The very important but also very large task will never be accomplished, simply because it's too big a task.
When product owners/stakeholders or other decision makers notice that their very important task is never prioritised, simply because is too risky to spend a lot of time on a large task when you can gain a higher combined value from all the smaller tasks, then they start subdividing large tasks into smaller more manageable tasks.
We want smaller tasks, because this reduces risk. Smaller tasks are easier to time estimate. Cost of failure is lower. Many small deliveries shows progress and reduces tendencies to micro-manage the software engineers.
If you can convince your product owners that WSJF is a great way to reduce risk, where they will see steady progress rather than having to wait a long time for a big splash - with all the associated anxiety, then everyone will be happier.
