标签：#design

The dashboard says forty instances, up from twelve this morning. The autoscaler did its job: it saw latency climb and threw hardware at it. And latency got worse. Not flat. Worse. You're paying for three times the compute to serve a slower product. Somewhere under all forty of those boxes is a single thing they're all waiting in line for, and every instance you add makes the line longer. Horizontal scaling multiplies work that doesn't have to coordinate. The instant the work does have to coordinate, more instances make it slower. Amdahl wrote this down in 1967: the serial fraction of a job sets a hard ceiling on how much faster you can go, no matter how much hardware you throw at the parallel part. Neil Gunther's Universal Scalability Law goes further: past a certain point, the cost of nodes coordinating with each other bends the curve back down. Add capacity, get less throughput. That ceiling was not set by the autoscaler, and it will not be moved by the autoscaler. It was set a long time before this morning, in a room, by whoever decided where the state lives and who has to touch it at the same instant. Now hand the service to a fleet of agents. It writes you something that looks built to scale: stateless handlers, a tidy repo, green tests, a canary that bakes fine at 1% traffic. Every gate you trust says ship it. And the bottleneck is sitting right there in the design, invisible to all of it, because the mistake isn't in the lines, it's in the shape. You cannot catch a shape problem by reading a diff. Name the hot state before you pick a framework. Where does the contended state live, and which requests touch it at the same instant? Answer that out loud, before anyone opens an editor. The tool is downstream of that answer, every time. Originally published at https://imacto.com/writing/scale-is-a-design-not-a-dial . Written with Claude Opus 4.8.

Design + Product Thinking: NYC’s Path to Reliable AI AI delivers value when it’s useful, trusted, and operational. For city services that affect millions, those qualities don’t happen by accident — they come from applying design thinking (who the service is for, how it’s used) together with product thinking (what outcome we’re trying to achieve and how we operate over time). This article explains why hiring designers and product managers matters for NYC’s digital and AI initiatives, summarizes the city’s PIT Crew program, and outlines how Flamelit applies outcome-focused delivery in the public sector. Why design and product roles matter Designers and product managers have distinct but complementary responsibilities that reduce common AI delivery failures: Designers (Design Thinking): center human needs, prototype user flows, and validate that interfaces and decision workflows are understandable and accessible. They surface usability and trust issues early, preventing technically accurate models from becoming unusable in practice. Product managers (Product Thinking): define the measurable outcomes, prioritize use cases, align stakeholders, and manage the lifecycle from discovery to ongoing operations. They ensure work is evaluated against mission impact, not just technical metrics. Together they prevent common failures: building technically impressive models that nobody trusts, deploying brittle systems without human review, or shipping features with unclear ownership that decay in production. PIT Crew and NYC hiring context NYC’s PIT Crew program is a city initiative designed to attract and staff product, engineering, and design talent for public service projects. It’s a practical recognition that public-sector digital transformation needs people skilled in user research, product management, and delivery. Read more about the PIT Crew and how it works here: https://www.nyc.gov/content/pitcrew/pages/ (open in a new tab). Hiring programs like PIT Crew help create the c

Introduction So imagine you are focused on your cappuccino-frappuccino doing something very important on you win laptop and then have a cringe attack due to the unknown Phone Link notification : Complete linking devices Your PC and mobile device are almost linked. Click here to continue linking devices. via Phone Link Then you switch off bluetooth, wifi, laptop - and you are right. What to do next ? Basic checks Settings -> Bluetooth & devices -> Mobile devices Settings -> Accounts -> Email & accounts Inspect recent notifications in Event Viewer eventvwr.msc Applications and Services Logs └ Microsoft └ Windows └ Notifications Applications and Services Logs └ Microsoft └ Windows └ Shell-Core Digital forensics Windows stores toast notifications in a local database, hence you need to install sqlite Get-ChildItem " $ env : LOCALAPPDATA \Microsoft\Windows\Notifications" output : Directory: C:\Users\$ USERNAME \A ppData \L ocal \M icrosoft \W indows \N otifications Mode LastWriteTime Length Name ---- ------------- ------ ---- d----- 1/1/2026 0:00 AM wpnidm -a---- 1/1/2026 0:00 AM 1000000 wpndatabase.db -a---- 1/1/2026 0:00 AM 10000 wpndatabase.db-shm -a---- 1/1/2026 0:00 AM 1000000 wpndatabase.db-wal wpndatabase.db is a SQLite database. connect to the database : sqlite3 " $env :LOCALAPPDATA \M icrosoft \W indows \N otifications \w pndatabase.db" query the Notification table . headers on . mode column SELECT Notification . Id , Notification . HandlerId , Notification . Type , Notification . ArrivalTime , Notification . Payload FROM Notification LIMIT 20 ; Then you will have something like : Id: [REDACTED] HandlerId: [REDACTED] Type: toast ArrivalTime: [REDACTED] Payload: <?xml version="1.0"?> <toast activationType= "protocol" launch= "ms-phone:fre/?cid=[REDACTED]&ref=FreIncompleteToast&reason=IncompleteNotificationsToast" > <visual> <binding template= "ToastGeneric" > <text hint-maxLines= "1" > Complete linking devices </text> <text> Your PC and mobile device are almost li

I keep coming back to java.util.ServiceLoader . I have used it to put a JSON layer behind a contract, so the core code carries no direct dependency on any particular JSON library and I can swap the implementation without touching callers. The same shape works for JWT handling, where the concrete library might be jose4j or another JOSE implementation, and you can easily find other decoupling use-cases. The motivation is always the same: the application should depend on a capability, not on a vendor. A while back I wrote about exactly that idea in Rediscovering Java ServiceLoader: Beyond Plugins and Into Capabilities , where the argument was to treat ServiceLoader as capability discovery rather than a plugin system. That piece hit the limitation everyone hits — the no-argument constructor — and worked around it with a default constructor plus a dynamic proxy that built the real object through a factory on each call. It works, but it is indirection bolted on after the fact, not a design. This post is the part I never pinned down back then: turning that workaround into a small, explicit pattern. The running example below is a mock payments system, with Stripe and PayPal specializations, because it is compact enough to show end to end. The JSON and JWT cases cited can be built with the same structure. The two limits ServiceLoader leaves you The first is the no-argument constructor. Whatever ServiceLoader instantiates must have a public, parameterless constructor. My StripePaymentService takes an API key, so it cannot be the class ServiceLoader loads — not unless I bolt on some init-after-construction step, which I would rather avoid. The second is selection, or rather the lack of it. ServiceLoader gives you every implementation it finds, in roughly classpath order. There is no id, nothing to prioritise on, and no way to ask whether a given one even applies in the current environment. With two backends on the classpath and only one configured, working out which to use is

Drawing from the enduring adaptability of HTML and HTTP, Seph Gentle proposes embedding self-contained schemas directly into file headers, ensuring data remains readable without external definitions. His experimental format prioritises forward, backwards, and sideways compatibility, enabling data format evolution without central coordination or data loss By Olimpiu Pop

An activity log tells us what an agent did. A decision log should also tell us what it considered and rejected. Without rejected options, a later reviewer sees a clean path that never existed: model B was selected, the task restarted, the result succeeded. Missing are the reasons model A was unsuitable, why staying put was worse, and what new evidence would change the choice. That information matters for trust and recovery. It lets people challenge a decision without reconstructing the entire session. Execution history is necessary, but different The MonkeyCode model-switch record at commit c58bcd4 stores the task and user, from/to model IDs, request ID, whether to load the session, success, message, session ID, and timestamps. The switch use case creates that switch record, restarts the task with the target configuration, and records the result. That is valuable execution history. It answers “what switch was requested and what happened?” The expanded rejected-options structure below is my design proposal , not a claim about MonkeyCode's current schema or interface. Add the decision before the outcome A reusable record can separate choice from execution: { "decision_id" : "task-42-model-switch-7" , "context" : "The task needs the required tool-call contract." , "chosen" : { "option" : "model-b" , "reason" : "Passed the declared capability contract" , "evidence" : [ "evaluation/capability-model-b.json" ] }, "rejected" : [ { "option" : "model-a" , "reason" : "Required tool-call case failed" , "evidence" : [ "evaluation/capability-model-a.json" ], "revisit_when" : "Adapter version changes" } ], "execution" : { "request_id" : "req-switch-7" , "result" : "success" , "session_id" : "session-9" } } The key field is revisit_when . “Rejected” should not mean universally bad. It should mean unsuitable under a specific context and evidence set. Design the interface for progressive disclosure Do not paste this JSON into the main task timeline. Use three layers: Timeline: Switch

I'll Be Honest: The Internet Already Has Translators I know. Language translation isn't a new idea. There are already huge translation platforms out there. So when I started working on a translator for my tools website, I wasn't thinking: "I'm going to reinvent translation." Not at all. My thought was much simpler: "Can I make quick translation feel less distracting?" My Frustration Was Actually Pretty Simple Sometimes I just need to translate text. That's it. I don't want to: Create an account Open five different menus Break a long text into tiny pieces Jump between multiple tools I want to paste the text... Choose a language... And get the translation. So I Built My Own Version 👉 https://allinonetools.net/language-translator/ The tool currently supports 200+ languages and language variations . You can: Detect the source language Select the target language Translate long text Upload text Use voice input Listen to the result Copy or share the translation And I wanted to keep the text experience simple without forcing users into tiny input limits. Just: Enter → Choose Language → Translate 200+ Languages Sounded Simple Until I Saw the List English. Hindi. Gujarati. Spanish. Arabic. These are the languages most people immediately think about. But then I started going through the full language list. Abkhaz. Acholi. Afar. Alur. Aymara. Baluchi. And many more. Honestly... I hadn't even heard of some of them before building this. That was probably my biggest learning moment. I Realized How Small My Own View of the Internet Was As a developer, it's easy to build around the languages we personally know. For me, seeing English, Hindi, and Gujarati feels normal. But the internet is much bigger than my own experience. Someone somewhere may be trying to understand a sentence in a language I've never even heard spoken. That changed how I looked at this tool. The Hard Part Wasn't Adding a Dropdown A dropdown with 200+ options looks impressive. But that's not the real problem. The

A panel on data ownership challenged the definition of "ownership," arguing it must extend beyond simple account control to include structural independence, interoperability, and community governance. Speakers like Zenna Fiscella, Paul Frazee, Boris Mann, and Robin Berjon emphasised the need for shared standards, unbundled platforms, and better tools to support user sovereignty. By Olimpiu Pop

In this podcast, Michael Stiefel spoke to Sarah Wells about the relationship of governance to software architecture. Governance enables teams to work effectively by establishing procedures that minimize system complexity, improve security, and reduce repetitive tasks. Targeted checklists help engineers by reducing the stress over these procedures. By Sarah Wells

Jake Lazaroff discussed the AT Protocol as a framework for distributed applications beyond social networking. He emphasised a local-first architecture where users maintain data in PDSs while leveraging shared infrastructure for synchronisation and updates. The presentation included experiments showcasing collaborative tools and highlighted the benefits of reduced reliance on app-specific backends. By Olimpiu Pop

For decades, software was designed around one assumption: A human would be the one using it. That...

At my workplace, I worked on an ERP platform used by fashion businesses to manage customers, body measurements, products, orders, invoices, inventory, staff, and other day-to-day operations. Each business also had a public storefront where customers could browse products and check out. The storefront started as a simple sharing feature. Businesses could publish products, copy a link, and send it to customers outside the main workspace. That worked well because the storefront was mostly a product catalogue, and most of the sales process still happened after the customer contacted the business. As the platform evolved, the storefront became much more than a catalogue. Customers were discovering businesses through shared links, browsing products, placing an order, and tracking orders directly from the storefront. That introduced new technical requirements around branded storefronts, SEO, server-rendered metadata, public checkout, pricing, and analytics. This article explores how I designed the storefront around wildcard subdomains, immutable shop identities, server-side shop resolution, and a scalable analytics pipeline. Table of Contents Giving the Storefront Its Own Identity Business Names, Reserved Names, and Subdomains Resolving a Storefront Active and Inactive Storefronts Location and Currency Product Pages and Share Previews Storefront Event Ingestion Processing Raw Events Counting Unique Visitors With HyperLogLog Domain Routing and Local DNS 1. Giving the Storefront Its Own Identity The original storefront was fairly simple. It was a React application that fetched a business and rendered its products. Beyond that, there wasn't much to it. There were no branded storefronts, analytics, subdomains, or even a separate identity beyond the business itself. Introducing those capabilities meant the storefront needed its own data model. I introduced a dedicated shop entity to represent the public storefront. The business remained the source of operational data such as cu

Instagram creators love engagement. Every comment is an opportunity to start a conversation, share a product, deliver a resource, or convert a viewer into a customer. The problem is that manually replying to hundreds or thousands of comments doesn't scale. At Vyral , we set out to build an Instagram AutoDM platform capable of serving thousands of creators while handling bursts of traffic generated by viral Reels. Instead of building a traditional chatbot, we designed an event driven system powered by Instagram webhooks, AWS services, and asynchronous processing. This article walks through the architecture, the engineering challenges we encountered, and the lessons we learned while designing a system that can process large spikes of comment events reliably. The Problem Imagine a creator with 2 million followers. A Reel starts trending. Within minutes: 10,000+ comments arrive Thousands of users comment the same keyword Instagram sends webhook events continuously Every eligible comment should trigger a personalized DM From an engineering perspective, this isn't a chatbot problem. It's an event processing problem. The system needs to answer questions like: Which comments qualify? Has this comment already been processed? What happens if Instagram sends the same webhook twice? What if the user deletes the comment? What if our service is temporarily unavailable? How do we avoid overwhelming downstream APIs? Those questions shaped the architecture far more than the messaging logic itself. Why We Chose Webhooks Instead of Polling Polling Instagram every few seconds would have introduced unnecessary latency and API usage for Vyral AutoDM . Instead, Instagram pushes events whenever something happens. The flow looks like this: Instagram │ ▼ Webhook Endpoint │ ▼ Event Validation │ ▼ Event Queue │ ▼ Workers │ ▼ Business Rules │ ▼ Send DM This architecture offers several benefits: Low latency Lower infrastructure cost Better scalability Natural decoupling between components Most i

Most of us treat design systems as a functional problem: consistent colors, consistent spacing, consistent components. That part's solved for most teams now. The part nobody writes down is tone. How should this loading state feel? Should this error feel scary or manageable? Is this confirmation message robotic or human? Here's what I've learned paying attention to that layer. Four moments that carry the emotional weight In any app, four states do most of the emotional work: Loading Error Empty Success Get these four right and the whole product feels better, even if nothing about the actual functionality changed. ** Loading: ambiguity feels worse than the wait itself** jsx // Vague, slightly anxious < Spinner /> // Specific, calmer < div className = "loading-state" > < Spinner /> < p > Fetching your latest data... </ p > </ div > A spinner with no context makes people wonder if something's frozen. A spinner with a short label tells them exactly what's happening. Same wait time, different feeling. Errors: same bug, different emotional outcome jsx // Robotic " Error: Request failed with status 500 " // Human " Something went wrong on our end. Your changes weren't lost, try again in a moment. " The second version does three things the first doesn't: it's plain language, it removes blame from the user, and it tells them what to do next. That's the difference between an error that frustrates and one that reassures. Success: robotic vs genuine jsx // Robotic " Action completed successfully. " // Human " Done! Your changes are saved. " This message shows up constantly across a typical app. If it reads like a system log every time, the product feels cold. A small rewrite makes it feel like a person is on the other end. Micro-interactions: timing is part of tone too `jsx// No feedback during the wait, feels broken <button onClick={handleSave}>Save</button> // Immediate feedback, feels responsive <button onClick={handleSave}> {isSaving ? "Saving..." : "Save"} </button>` A butt

Learn TypeScript From First Principles to Senior/Staff-Level Production Engineering If you searched for how to learn TypeScript properly — not just the syntax, but the thinking behind it — this guide is built for that. Most TypeScript tutorials stop at "here's an interface, here's a generic." This one goes further: it's a single, exhaustive TypeScript tutorial and reference that walks through the type system, object-oriented programming, generics, async programming, design patterns, SOLID and DRY principles, error handling, testing, and the tooling that real production teams run in CI — the same TypeScript best practices used at top-tier engineering organizations. Whether you're a beginner looking for a structured TypeScript for beginners path, or an experienced JavaScript developer making the jump to advanced TypeScript and system design, you can read this end to end or jump straight to the section you need using the linked table of contents below. Table of Contents 1. Introduction — What Is TypeScript & Why It Exists 2. Installation, Setup & tsconfig.json Deep Dive 3. Variables & the Complete Type System 4. Functions — Every Form, Overloads, this , and Best Practices 5. Arrays & Tuples 6. Objects & Type Aliases 7. Interfaces 8. Enums & Literal Types 9. Union, Intersection & Discriminated Unions 10. Type Narrowing, Assertions & Type Guards 11. Classes & Object-Oriented Programming 12. Generics — Basic to Advanced 13. Modules, Namespaces & Project Structure 14. Asynchronous Programming — Event Loop to Production Patterns 15. Advanced/Utility Types & the Type-Level Programming Toolkit 16. Design Patterns in TypeScript 17. SOLID, DRY, KISS, YAGNI — Principles Applied With Real TS Code 18. Error Handling Strategies 19. Testing TypeScript 20. Tooling, Linting, Build Systems & CI/CD for Production TS 21. Performance, Compiler Internals & Scaling Large Codebases 22. Interview Cheat Sheet (Expanded) 23. One-Page Quick Revision Sheet 1. Introduction — What Is TypeScript & W

Reddit looks simple and hides two genuinely hard problems. Comments nest arbitrarily deep, and a naive tree structure makes loading a busy thread slow. The front page reorders itself constantly, so ranking cannot just count votes or old posts would never leave. Both problems have well-known answers, and both are good lessons in choosing the right model. The core problem A comment thread is a tree. Each comment can reply to any other, so depth is unbounded. If you store only "this comment's parent id" and then try to load a whole thread, you walk the tree one level at a time, one query per level, which gets slow for deep or wide threads. Loading a popular post with thousands of nested comments should not take thousands of queries. Ranking is the second problem. If the front page sorted by raw vote count, the highest-voted post of all time would sit at the top forever. If it sorted by newest, quality would drown in noise. You need a score that blends how good a post is with how fresh it is, so good new posts can climb and old ones fade even if they were once popular. Key design decisions Store the parent pointer, but do not traverse at read time. The simple model is a parent_id per comment, which is easy to write but expensive to read as a tree. To load a thread cheaply, fetch all comments for the post in one query, then assemble the tree in application memory. One read, in-memory tree building. This works because a single post's comments, while numerous, fit in memory to assemble. Consider a path or closure model for deep trees. For very deep threads, some systems store a materialized path on each comment, an encoded ancestor chain, so you can fetch an entire subtree with a single prefix query and sort by the path to get correct display order. Another option is a closure table that records every ancestor-descendant pair, which makes subtree queries direct at the cost of extra write work. The right choice depends on how deep threads get and how often you read subtrees

Searching billions of documents for a phrase and getting ranked results in tens of milliseconds looks like magic. It is not. It comes down to two ideas working together: an index that maps words to documents instead of scanning documents for words, and a way to spread that index across machines so each holds only a slice. Understand both and full-text search stops being mysterious. The core problem A database scans rows. If you ask a plain database to find every document containing a word, it reads documents and checks them, which is linear in the amount of data. That is fine for exact key lookups and hopeless for free-text search across huge corpora. You need the opposite mapping. Instead of "given a document, what words does it have", you want "given a word, which documents have it". That inversion is the whole trick. The second problem is size. One machine cannot hold the index for billions of documents, and one machine cannot serve the query load. So the index has to be split across nodes, and a query has to find the right nodes and combine their answers. Key design decisions Build an inverted index. At index time, each document is broken into tokens by an analyzer that lowercases, splits on word boundaries, and often strips or stems words. For every token, the engine keeps a posting list: the set of document ids that contain it, often with positions for phrase matching. A query for a word becomes a direct lookup of its posting list, not a scan. A multi-word query intersects or unions posting lists, which is fast because the lists are sorted. Store the index in immutable segments. New documents go into small new segments rather than editing existing ones. Segments are immutable, which makes them cache-friendly and safe to read without locks. A background process merges small segments into larger ones over time. A delete is just a marker; the document is removed for real during a later merge. Split an index into shards. An index is divided into shards, each a sel

Adding cloud regions changes latency and cost in ways simple math can't capture. This article presents a framework from multiple launches: decompose your latency budget before committing to infrastructure, choose deployment patterns by consistency and traffic profile, and optimize before expanding. A phased approach cut latency 35% through routing alone, before a new region brought it under 60ms. By Uttara Asthana

How I moved from a traditional web application mindset to exploring local-first architecture I wanted to build a simple software tool for my personal use. Nothing complicated. Something in the category of tools people build for themselves: A personal expense tracker A budgeting application A private knowledge management tool A personal organization system The important characteristic was this: The data belonged to one person. It was not a social application. It was not a collaboration platform. It did not need users interacting with each other. There was no requirement for: Public profiles Sharing updates Real-time collaboration Social features It was simply a tool that helped one person manage their own information. When I started thinking about building it, my first instinct was the most natural one for me. I am a web application developer. My comfort zone is building web applications. So my first thought was: "Why not build a Ruby on Rails application?" Something like: User | Web Application | Ruby on Rails API | PostgreSQL Database This is an architecture I have worked with many times. The workflow is familiar: Create models Build controllers Add authentication Store data in a database Deploy the application Access it from anywhere This is a proven architecture. For many products, this is exactly the right approach. But while thinking about this project, I asked myself a different question: Am I choosing this architecture because the problem requires it, or because it is the architecture I already know? That question changed the direction completely. Understanding The Actual Problem Before choosing technology, I wanted to understand the nature of the problem. What kind of application was I actually building? There is a big difference between building: A social network A marketplace A collaboration platform A communication application versus building: A personal tool A private utility A single-user productivity application In the first category, the server is the

Google shipped AlloyDB AI functions GA with a proxy model architecture that trains a lightweight local model from LLM outputs, then runs queries at database speed without external calls. Smart batching delivers 2,400x throughput improvement. The proxy model reaches 100,000 rows per second in preview, but benchmark numbers apply only to ai.if in internal testing. By Steef-Jan Wiggers