Show HN: NaturalCron – Human-Readable Scheduling for .NET (With Fluent Builder) https://ift.tt/7Qt2Dv6

Show HN: NaturalCron – Human-Readable Scheduling for .NET (With Fluent Builder) Hi HN! I built NaturalCron because I was tired of writing and debugging CRON syntax like: /5 * * 5 Now you can write something human-readable in .NET: var expression = new NaturalCronExpression("every 5 minutes on friday"); Or use a Fluent Builder for strong typing and IDE support: var expression = NaturalCronExpressionBuilder .Every().Minutes(5) .On(DayOfWeek.Friday) .Build(); Great for: - Code-based scheduling in .NET apps - Overriding schedules from configs or databases - Displaying easy-to-read rules in UIs NuGet: https://ift.tt/MJIo3nv GitHub: https://ift.tt/n62slh5 Would love your feedback on syntax, builder design, and what features you'd like to see next! https://ift.tt/n62slh5 August 2, 2025 at 05:09PM

Show HN: Fast Elevation API with memory mapped tiles https://ift.tt/Fzyng3f

Show HN: Fast Elevation API with memory mapped tiles I recently wrote and launched a high-performance Elevation API, built from the ground up, in C. I was highly inspired by the handmade community and I was intrigued by the idea of handling fairly large datasets and optimizing caching and smart prefetching, and to cream out maximum performance in terms of latency and handling large loads. The whole thing is built from scratch. I wanted to roll my own high performance server that could handle a lot, mostly for the technical challenge but also because it brings down hosting costs. At the core is a hand made TCP server where a single thread handles all I/O via epoll, distributing the events to a pool of worker threads. The server is fully non-blocking and edge-triggered, with a minimal syscall footprint during steady-state operation. Worker threads handle request parsing and perform either direct elevation lookups for single- or multi-points, or compute sample points along polyline paths. The elevation data is stored as memory mapped geotiff raster tiles, The tiles are indexed in an R-tree for fast lookup. Given a coordinate, the correct tile is located with a bounding-box search algorithm through the tree, and the elevation value is extracted directly from the mapped memory. If the tile is missing the data, underlying tiles act as fallback. I also implemented a prefetching mechanism. That is, to avoid repeated page faults in popular areas, I employ a strategy where each tile is divided into smaller sub-tiles. Then, I have a running popularity count per sub-tile. This information is then used to guide prefetching. More popular sub-tiles trigger larger-radius prefetches around the lookup point, with the logic that if a specific region is seeing frequent access, it’s worth pulling in more of it into RAM. Over time, this makes the memory layout adapt to real usage patterns, keeping hot areas resident and minimizing I/O latency. Prefetching is done using linux madvise, in a separate prefetch thread to not affect request latency. There’s a free option to try it out! https://ift.tt/uVxUIdS August 3, 2025 at 01:12AM

Show HN: Open-sourced my prompt management tool for LLM-powered apps https://ift.tt/NAWc8pi

Show HN: Open-sourced my prompt management tool for LLM-powered apps https://ift.tt/24qh5Ak August 3, 2025 at 12:12AM

Show HN: Agentic AI Frameworks on AWS (LangGraph,Strands,CrewAI,Arize,Mem0) https://ift.tt/ajKVGQM

Show HN: Agentic AI Frameworks on AWS (LangGraph,Strands,CrewAI,Arize,Mem0) We’ve published a set of open-source reference implementations on how to build production-grade Agentic AI applications on AWS. What’s in the repo: • Agentic RAG, memory, and planning workflows with LangGraph & CrewAI • Strands-based flows with observability using OTEL & Arize • Evaluation with LLM-as-judge and cost/performance regressions • Built with Bedrock, S3, Step Functions, and more GitHub: https://ift.tt/0P6SvkR... Would love your thoughts — feedback, issues, and stars welcome! https://ift.tt/KA1EvaZ August 2, 2025 at 04:20AM

Show HN: Windows XP in the browser, with file system, Word, media, flash https://ift.tt/rzZoOJ4

Show HN: Windows XP in the browser, with file system, Word, media, flash https://ift.tt/SrT3Xnq August 2, 2025 at 05:11AM

Show HN: List of Clojure-Like projects https://ift.tt/yMNoC3t

Show HN: List of Clojure-Like projects https://ift.tt/JCVtETY August 2, 2025 at 12:17AM

Show HN: LinCal – A Calendar View for Linear Issues https://ift.tt/UlmbVwo

Show HN: LinCal – A Calendar View for Linear Issues I recently migrated our marketing agency's work to Linear. It's been fantastic, but we immediately ran into a problem: there was no easy way to visualize our content pipeline on a calendar. For social media, blog posts, and other content with specific publish dates, a list or board view just wasn't optimal for seeing the "flow" over a month. To solve this, I built LinCal.app, a web app that acts as a calendar for Linear issues. How it works: - Log in with your Linear account - Filter issues based on team, assignee, project, cycle, and more - Open issues with a click in separate browser tabs (LinCal right now is a read-only app - not changing any Linear data) - show/hide weekends/subtasks - View issues within this filter that do not have a due date If you are a Linear user and would appreciate a different view on your work, I'd love for you to check it out and hear your thoughts https://lincal.app August 1, 2025 at 10:44PM