Compared DeepSeek Flash v4.1 to Sonnet 5.5

I have a medium size app around 10k lines of codes (getting bigger everyday). It is written in PHP and JS. It is under active development. New features are added, bugs are fixed every week or so. In my test case, we had an issue with pdf rendering (DomPDF) and preview of the PDF in html/css. Users decide which font to be used and where the text is placed on the pdf. They also upload an image which may be vertical or horizontal oriented. Different images may be uploaded for different cases where rest of the pdf settings may be shared or not. Here is the prompt i passed each of them: ``md I manage the participation and thank-you certificate settings on@pages/kongre_ayarlar.phpand handle their delivery through@pages/sertifika_katilim.php. The same applies to@pages/sertifika_kurs.php`. However, I have identified some serious issues here. First of all, for the second and subsequent courses, the "use the settings of the first course" option seems to be applied and stored only when the certificate is uploaded. When I change the settings of the first course, the changes are not reflected in the second and subsequent courses. Another issue is that the preview and the actual PDF layout do not match. For example, I set the top position to 550px. It looks perfectly aligned in the preview, but when I open the PDF, it appears much further down. The third issue is, I think, related to CSS fonts being loaded. This seems to cause DOMPDF to have problems with accented characters. While the situation is relatively good with participation and thank-you certificates, it is much worse with course certificates. Could you investigate these issues and prepare a plan for fixing them? ``` I used Claude Code with Pro subs Sonnet 5.5 (medium) I used DeepSeek Harness Desktop App (just realeased) with Flash v41 High • It took 10 min 37 secs for Flash4.1 to come up with a plan. Whereas It only took 4 min for Sonnet to come up a plan. • With Sonnet 5, I always though DS is alot faster. However with Sonnet 5.5 it is incredibly fast. • Their findings are completely same. This amazed me actually. The offered plan is like raeding same text with different paraphrases. On the other hand, they differ very much in implementation. • It took 35:47 min for DS to finish the plan. • It took only 11:43 min for Sonnet. • Sonnet updated/created 8 files (including 2 sql files) • Flash updated/created 13 files (including 2 sql 2 md files files) • Opus 5.5 was updating TODO and CLAUDE md files all the time. Sonnet 5.5 did not. Flash on the other hand did updated them. (i did not ask) • Claude has the memory available for the said repo. • It was the first time for DS on this repo. • DeepSeek used 520K token in context • Claude used 190K token in context • DeepSeek costed 1 USD • Claude used 10% of 5 hour limit. On the personal taste side: - Sonnets implementation is alot easier and to read and follow. - Flashs implementation is more detailed. Ironed out some bugs / inconsistent behaviour on the way (something i see with opus. sonnet high be of help) - Flash attach more importance on front end side experience. Test it thoroughly. - Medium effort Sonnet is not that efforty! - Claude usage limits are way better than previous narrowed window. - sonnet 5.5 does use less tokens and response alot faster.