That's only if you're expecting a candidate to provide a perfect solution; and don't make it clear that the time limit should inform their design and not just measure their speed of implementation.
Part of software development is tailoring a solution to the scope of the problem, and this includes taking into account the time and effort available to come up with a solution. Someone who looks at that problem statement and designs something that will take a week has missed a very important requirement.
You could reasonably scale up any problem to take an arbitrarily long amount of time, by adding onerous requirements (must have 7 9's of reliability). What I've found more rare and precious is the developer who can limit the scope so that items that are not up for negotiation like time (2 hours) & resources (1 developer) are respected.
I fully expect a developer to state their assumptions up front, so that I can judge their design based on the stated assumptions and not some unstated imaginary assumptions. It also lets me see how or if they prioritize.
Part of software development is tailoring a solution to the scope of the problem, and this includes taking into account the time and effort available to come up with a solution. Someone who looks at that problem statement and designs something that will take a week has missed a very important requirement.
You could reasonably scale up any problem to take an arbitrarily long amount of time, by adding onerous requirements (must have 7 9's of reliability). What I've found more rare and precious is the developer who can limit the scope so that items that are not up for negotiation like time (2 hours) & resources (1 developer) are respected.
I fully expect a developer to state their assumptions up front, so that I can judge their design based on the stated assumptions and not some unstated imaginary assumptions. It also lets me see how or if they prioritize.