System design
Shaping how a system fits together, from APIs and data models to the boundaries between its parts.
System design is the work of deciding how the pieces of a product fit together. Where the boundaries sit, what the data model looks like, how components talk to each other through APIs, and which abstractions will still make sense in five years.
It’s the area I’d name as my specialism. I’ve designed systems from high-traffic platforms handling hundreds of thousands of concurrent users to agentic AI workflows combining deterministic code with language models, and I’ve untangled plenty of systems designed by others.
Good design shows up as simplicity. The right boundaries make a system easier to change, easier to test, and easier for a new engineer to understand.
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