My astronomical software development: (1) Citizen Science project: tracking space debris https://www.gov.uk/government/news/out-of-this-world-citizen-science-brings-astronomy-data-to-dstl This project required millisecond time resolution. The time stamps from commercially available DSLR control software had insufficient accuracy. I wrote DSLRTrigger to solve this problem and it was successfully used on the project. I also wrote the software used to test and calibrate the timing accuracy. All the software is freely available on my website. (2) PixInsight script PhotometricMosaic. This is used to create a mosaic from 2 or more images. It uses stellar photometry to determine the brightness scale differences between the two images, and then uses a surface spline to correct the gradient between them. (3) PixInsight script NormalizeScaleGradient. This is used after registering the images but before stacking. The target images are corrected to match the reference frame. This involves matching the brightness scale (using stellar photometry) and removing the relative gradient (using a surface spline). It can significantly improve the stacked result. (4) I spend time supporting users on the PixInsight forum. I have also written detailed reference documentation.