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How do you structure your program to do this?

I had huge success writing a trading system where everything went through the same `on_event(Inputs) -> Outputs` function of the core and a thin shell was translating everything to inputs and the outputs to actions. I actually had a handful of these components communicating via message passing.

This worked rather well as most of the input is async messages anyway, but building anything else this way feels very tiresome.

If you need to support multiple versions at the same time, you need to extend TBD in some way.

We just cherry-picked stuff back to release branches, if we needed a fix.

I am on-call for a week every ~8 weeks. I get 500 € and two additional days of vacation for it. If I do get a call, the additional hours go to my time account.

Fair deal, I'd say. Only problem is that most of the applications are from vendors, so getting problems fixed is an ordeal.

DDD is against the idea of having a single unified model; instead it divides a large system into bounded contexts, each of which have their own model.

If you have a large system it makes sense to divide it into smaller independent pieces. If you have a (micro)-service architecture you have distinct services, in a monolith you might have modules.

It is a hard problem to know where exactly the boundaries between services or modules should be, in any case DDD calls the things that make sense to decouple bounded contexts.

Define that function directly in the place where it is used (e.g. as a lambda, if nesting of function definitions is not allowed). Keeps the locality and makes it obvious that you could just have put a comment instead.

Polars 3 years ago

Is there a good book/overview on how dataframes and OLAP query engines work under the hood?

Git Things 3 years ago

In one of the best teams I worked with we started doing that on our own. I still do it (not always, but often) on my projects.

Do you have a auction + continuous market as well? With same or with different granularity?

Europe has an day-ahead auction with 1h products and continuous trading with quarter hours as the smallest product (still varying from country to country).

Energy costs vary not only over the day but per quarter hour in each hour, e.g. during the morning the last quarter is cheaper than the first for each hour. So you don't necessarily have to shut down the machines, maybe you can just move the most energy expensive phase into another quarter.

If you are brewing beer you have times where you have to heat it and times where it needs to sit at a given temperature. Try to optimize the process to heat during cheaper quarter hours.

Long time ago I learned that a database is any kind of structured, machine readable data. A database management system is the software that manages these databases and databases + database management system = database system. Dunno if recalled correctly.

Directly afterwards I got told that no one ever uses these words correctly, but the professor felt obliged to at least tell us the academic definition once.

Since this was a German lecture, some time was spent on the correct plural of schema (german: Schema). The options presented were Schema, Schemas, Schemata and everything was allowed as long as it is not Schemen (multiple shadowy figures).

Dunno why I remember this. It's the only part of the lecture I really remember.