greatest-hits

tinyblok is the obvious next experiment after monoblok: can the patchbay run on a microcontroller and ship sensor data straight into a remote NATS cluster? In the original post, the Peter’s Porsche Rentals worked example put a Raspberry Pi behind the glovebox; an ESP32 is an order of magnitude cheaper and smaller. Coupled with a 4G mi-fi or the car’s onboard Wi-Fi, it’s a self-contained edge node that can sit on a OBD2 dongle’s worth of power and select what crosses the mobile data connection....

Want to jump straight to the code? A car publishes its engine RPM ten times a second. A market data feed ticks on every quote. A cheap temperature sensor posts a fresh reading every two seconds, mostly identical to the last one. Data moves quickly, but most of it is noise: a publisher that doesn’t know what its subscribers care about, and a fleet of subscribers each writing the same defensive code to round, debounce, and ignore the boring readings....

The Excel C SDK dates from the early 1990s. Memory management is manual, the type system is painful, and there’s almost no tooling. Despite all of this, it remains the only way to build add-ins that run truly in-process with Excel, supporting multi-threaded recalculation and the full breadth of what the host application can do. If you want the best possible performance, you need an XLL. But it’s a foot gun....

I have used NATS on various projects over the years. It provides a high performance transport layer than can be used to connect applications and services. If you haven’t already heard of it, this video is a fantastic primer. NATS supports websocket connections. nats.ws runs in browsers. This means we can directly use NATS as the backend for browser-based applications that need to display realtime streams of data. Why is this interesting?...

Back when we all used SQL databases, it was common to paginate through large result sets by appending LIMIT offset, rows per page to a SELECT query. Depending on the schema, data volume and database engine, this was inefficient to varying degrees. On smaller result sets and with the right indexes, it was… posssibly OK. On larger result sets, the high page numbers would get progressively slower. Databases like DynamoDB prevent this inefficiency by handling pagination differently....

Here is one of my bad ideas that was nevertheless fun to think through. I am not suggesting you actually do this for anything serious. Really, I’m not. Serverless data technologies already exist. The idea I really like ClickHouse. Compared to the expanse of complex software in the big data space, it’s refreshing to run a single process. Although not without its foibles, it’s very fast and versatile. Running it on Cloud Run is likely a bad idea....

This project started when my son asked me for a replica train departures board for Christmas. I thought this was a great idea and this looks to be a really neat implementation, but I wanted us to have a go at building one ourselves. I promised that if we failed miserably I’d buy him one! After getting some off-the-shelf code up and running, I wanted to rethink the software. The resulting code is available on GitHub....

Back in my early teens when I started developing what could loosely be called software, I didn’t know what I was doing. If it compiled, ran and produced mostly the expected results, then the job was done. As a new programmer, I was immensely productive. Of course, problems came when it was time to fix bugs or extend the software. It was often easier to just start again than to try and understand the rat’s nest of poorly structured and unintelligible code....