UPDATE
Final offer. I cannot afford it lower - but then again I will possibly have other better paid project(s) at the same time that's why the deadline is longer.
END OF UPDATE
Hi there, I'm Matt Sergei (do call me Matt, please) and can create such D3.js based splay tree -
please state exact functions you would like to have as they are on your referenced web page. Otherwise a list of features/functions to implement can never be fixed.
I'm writing you this because there's a complete object and animation javascript library implemented behind your page (so nodes and edges are created/deleted and animated) and D3.js of course doesn't have that less than animation between two data states (called transitions).
So for each operation a new tree state needs to be set by custom script then animate the transition (this might be done automatically by D3.js). And of course all visualizations before actual adding, deleting and finding the given node.
Otherwise I’m a webmaster and developer for 26 years, implementing web animations/charts/visualizations with SVG, D3.js and GSAP (and other) libraries for 7+ years. Usually I have to fix incomplete D3.js work by other freelancers twice per year (4 times last year).
This is otherwise 750 EUR project for me (I'm incorporated) yet can do that for the proposed budget because I like to help and enjoy scripting with D3.js library.
Regards and hope you're safe,
Matt