| Hi HN, Alex here, designer-engineer in the Netherlands. My day job is
Repper (a pattern-design tool). Skymap is a side project, built last
weekend in 4 days (~32 hours, AI-assisted with Claude Code). I've followed Anton Petrov on YouTube for years and kept seeing nice
pans over galaxy catalogs in research videos, thinking "why can't I just
fly through that?" Aparently nobody had built it for the browser yet. It loads SDSS (~500k galaxies), 2MRS (~45k), and GLADE (~2M) as WebGPU
instanced billboards. Past a certain on-screen size each galaxy
crossfades from a dot into a procedural oriented disk (catalog
axis-ratio + PA from HyperLEDA / 2MASS XSC), then into a real survey
image when close enough: SDSS DR18 ImgCutout, or DSS via CDS hips2fits
for the rest. There's a cosmic-web filament overlay built offline with
DisPerSE (Sousbie 2011), a faint blue lattice over the point field.
Striking at supercluster scale. What I genuinely like about coding with Claude is that I can read about an
algorithm in a paper and have it running interactively the same
evening. DisPerSE skeletons, Schechter LF corrections, HEALPix
re-weighting, K-correction in the fragment shader. Stuff I'd otherwise
only have watched a video about. The interesting texture across these 4 days wasn't bug-fighting, it
was iteration: continuous refactoring, guiding Claude away
from slop, accepting that scaffolding gets re-done. The renderer
wasn't new ground (years of WebGL behind me). Deep-link
resolution and tier swaps end up as a useEffect-and-refs web I'd
normally write as redux-saga; I went fully agentic this round and
you can feel the absence of an orchestrator (ouch). Live: https://skymap.rulkens.com
Repo: https://github.com/rulkens/skymap (MIT)
DOI: https://doi.org/10.5281/zenodo.20037028 UX has plenty of rough edges, mobile gestures aren't there yet. I'm not
an astronomer (the cosmology math is all Claude-derived against
textbook formulas), so if anyone here works in the field and spots
something off, I'd love to hear it. I'm also curious how people grow a side project from a code seed to something
that is robust enough to be used in production, especially with agentic
coding. I feel I learned a lot about this, but I'm curious about your
experience. TBH, I like my code clean, so with the speed this is going
I end up with a lot of cringe code that I'd wish would be better. |