I am Jose Alejandro, possess the full stack development skills and extensive Python expertise which makes me the ideal fit for your project. I can design and implement a tailored solution to parsely parse data from Gmail straight into Gsheet using a Gmail addon script, which not only avoids any third-party costs like Zapier but also ensures optimal speed and accuracy for your specific requirements.
As you mentioned that the number of delivery lines in an email can vary up to 25, my deep understanding of Gmail APIs alongside advanced scripting skills will enable me to implement a robust algorithm that can handle this variation expertly. I would divide the project into two parts: first, defining email threads with similar subject lines and isolating the latest one, and secondly, extracting the required details such as Delivery ID, Date, Time, Product, Specs, and Quantity. This means even though your Gmail thread has multiple emails with different deliveries, my solution will always provide you with only the most recently received data.
Moreover, leveraging my proficiency in JavaScript and frameworks like React and Vue.js would allow me to create an intuitive user interface for this project's front-end. By visualizing these valuable parsed data on the Gsheet in a user-friendly manner, we can simplify your analysis process greatly. So if you are seeking an experienced freelancer who can deliver a seamless parsing solution within budget and on time, then look no further.