I am currently the only software developer in a small oil company (50 employees or so), I have handed in my notice (4 weeks) but have been asked to continue working for the company in my spare time after my official leave date until they have managed to hire a replacement and they will pay me to do so.
In my contract it does not say anything about working after your notice has finished. The amount I am currently earning is not that good. How can I secure a better rate for this work? Are there conventions for rates for post-employment consulting like this?