Will customisations need to be redone when I update versions

This depends on the changes made. In general its normal that minor releases will not break many addons, while major releases are likely to break addons. In general its not needed to completely rewrite addons, but if an addon breaks then it will need to be updated so that it works again.

CS-Cart 3.1.0 is coming. As this will break admincp improvements, I would expect that this could break addons that change admincp functionality. Its hard to say exactly.



I'm currently in the process of having a large number of addons created, while the first batch has been completed. I expect that some of these will have to be updated when 3.1 comes out.

Also see the KB for the my changes add on



John

All depends on what your changes were and how they were implemented. A developer who is well versed in cs-cart can make changes with the least risk of requiring further maintenance from an upgrade. Then there are others who do things in a fashion that is almost guaranteed to provide them future revenue every time you upgrade.



Changes come in basically 3 flavors:

MODS - changes to the distributed files of the system (least desirable)

HOOKS - Isolating local changes (functional and visible) so they are independent of the upgrade (most desireable)

ADDON - Using a separate addon specific to a change provides an even greater insulation to upgrades. An addon would use HOOKS and has the ability to add language variables on installation, create DB tables, etc.



Best approach is to ensure that the developer you choose has lots of experience developing for cs-cart. As with most things, get references and check them. Also ask for specific sites that might have had changes they've done which are similar to yours. Even if you are unique, you can check references for quality, delivery on commitment and cost. Cheaper is not always better.