Starfighter is divided into N tech trees, where as of the Chapter 1 release N = 2. Each has a distinct player-facing UI and, generally, some specialized backend systems, but they're all a part of the same product, behind the same login, running off the same message bus. Each tech tree has a series of levels: start at level 1, beat it and unlock level 2, etc. The levels do not necessarily progress linearly and trees can interact with each other in terms of level requirements, although I don't know if any levels requiring, etc, "passed $FOO in algorithmic trading and either $BAR or $BAZ from low-level programming" will ship in Chapter 1.
Each level has its own goals/victory conditions/etc. There may be interplay between levels, such that your past/simultaneous performance on one allows you to do X, Y, or Z advantageous thing in the other. Those interactions might happen across tech trees. I am saying "might" here because I haven't coded any level which actually does that but it came up at design meetings and our systems support it -- not sure if it will happen in Chapter 1 but I'd rate it as "highly likely" it happens in Chapter 2.
Chapters: we intend on doing a new content release (which adds to, rather than replaces, existing content) every 6~8 weeks, with a new tech tree introduced roughly every 2~3 chapters.
Would love anyone's thoughts on "How do I explain this succinctly such that I don't turn-off anyone who is less interested in a particular tech tree?"