@icarusza You would like Elixir. The creator, Jose Valim, was (or perhaps still is) a core maintainer of Rails and Ruby heavily inspired the design of the language.
Direct payment is generally not advisable as you'd be handling cardholder data directly. This makes you subject to stringent PCI-DSS compliance - which is time-consuming, costly and requires ongoing compliance measures. This is to ensure that as your business scales in transaction volume that...
Elixir - it's syntactically elegant, concise and targets the BEAM - providing performant, resilient, and highly-available applications for free. The native developer tooling supporting it and dependency management is excellent. It's my first-choice for writing applications that require realtime...
I would recommend "Introduction to Algorithms" by T. Cormen, et. al. It provides comprehensive coverage of the landscape and structures that you will encounter which are derived from first principles, escalating in complexity and finalising by providing supplementary theoretical material to...