As for some more technical details, the implementation is a fairly standard unidirectional backwards path tracer written in C++17 which runs on the CPU. Some notable features it includes are: a custom PBR material model (supporting opaque/translucent dielectrics and conductors), basic SAH BVH construction and ray acceleration, BSDF importance sampling (using VNDF sampling for GGX), next event estimation, basic power/area weighted light sampling, arbitrary emissive geometry, russian roulette path termination, a thin lens camera model (for simple depth of field), multiple importance sampling, and ACES tonemapping.
The image itself was rendered at 3840x2160 with 10,000 samples per pixel on a Ryzen 9 3900X in about 12 hours with the help of my friend anthropy (I only have a 3800X). The scene presented within the renderer was made specifically for this project by OleanderTheHorse, most notably being authored to satisfy the renderer's lack of texture support by using purely per-face materials and a more low-poly style. Note to render this scene in a reasonable amount of time a modified version of it was used that actually utilized multi-threading, otherwise such a noise-free render would've taken an eternity on a single thread.
Finally, the source code for this project was designed to be as minimal as reasonably doable even if that came at the expense of micro-performance optimizations, mainly for artistic purposes. The actual source will be publicly available soon, I just have not yet finished crunching it down to a small ASCII art program yet as it takes a lot of time to do by hand and I want to get this submitted before the deadline. Additionally running the code itself will be fairly impractical due to how long a single threaded version of it takes to execute, but the purpose is more just to be artistic with its presentation rather than practical.