标签：#Design

As software engineers, we often architect solutions in a virtual ideal: fast networks, elastic resources, and servers that never physically degrade. But what happens when your carefully crafted systems need to interact with the messy, unpredictable physical world? Think factory floor monitors, real estate camera networks, or remote tracking devices. Suddenly, those cloud assumptions about infinite uptime and perfect connectivity crumble. My journey, particularly architecting and maintaining a continuous 24/7 camera livestream for a real estate group over six years, has been a masterclass in this reality. It's revealed that true reliability in the physical realm demands a hybrid approach – one that intelligently merges the power of edge computing with the scalability and data insights of the cloud. This isn't just about connecting devices; it's about building resilience into the very fabric of your architecture. In this article, I'll share the battle-tested strategies and design principles that enable systems to not just survive, but thrive, despite the harsh realities of physical deployment. 1. The Core Strategy: Smart Edge, Simple Cloud One of the most common pitfalls in hybrid architecture design is treating the edge device as a mere 'dumb' terminal, solely responsible for streaming raw data to a powerful cloud backend. This approach creates a critical single point of failure: if the network drops, the entire system grinds to a halt. Instead, I advocate for a Smart Edge, Simple Cloud architecture. This principle establishes a clear division of responsibility: The Edge : This is where the magic happens locally. The edge system should be robust enough to handle local processing , data filtering , buffering , and immediate hardware control . Critically, it must be capable of operating autonomously for extended periods without an active cloud connection. Think of it as a mini data center, designed for self-sufficiency. Benefits of a Smart Edge : Reduced bandwidth cost

The Counterintuitive Truth: Feature Flags Are Not Config Files Most engineers first encounter feature flags as a simple abstraction: a key-value lookup that returns true or false. That mental model works fine for a single service handling a few hundred requests per minute. It becomes actively dangerous at scale. A mature feature flag system isn't a config file with an API wrapper — it's a distributed control plane . The distinction matters architecturally. A control plane manages the real-time behavior of a running system across many nodes simultaneously, with its own consistency guarantees, failure semantics, and propagation latency. That's a fundamentally different design problem than reading a YAML file on startup. One constraint drives every downstream decision: user traffic must never block on a remote flag service call. If evaluation requires a synchronous RPC, you've coupled your request path to the availability and latency of an external system. Netflix's Archaius library enforces this by evaluating flags entirely in-process against a locally-cached configuration snapshot. A network round-trip per evaluation injects 10–50ms of tail latency at p99 — catastrophic when you're competing on streaming start times measured in hundreds of milliseconds. Google, Meta, and Netflix collectively evaluate flags against millions of requests per second with sub-millisecond overhead. That figure is only achievable through local evaluation backed by an async synchronization layer, not RPC. The other failure mode engineers underestimate is flag sprawl . Systems accumulate flags the way codebases accumulate dead functions — gradually, then all at once. I've seen services carrying thousands of flags where fewer than 10% were actively managed. The operational weight alone becomes a liability: which flags are safe to remove? Which ones are kill switches for production behavior that no one documented? Knight Capital's $440M loss in 45 minutes in 2012 remains the canonical cautionar

Enterprise Design Patterns in Python: Repository & Unit of Work 🐍🏗️ Series: Enterprise Application Architecture | Source: Fowler's EAA Catalog | Code: GitHub Repository 🧠 What Are Enterprise Design Patterns? Martin Fowler's Patterns of Enterprise Application Architecture (2002) is one of the most influential books in software engineering. It documents recurring architectural solutions — patterns — that solve common problems in enterprise systems: how to organize domain logic, how to talk to databases, how to handle transactions, and more. In this article, we'll explore two of the most powerful and widely-used patterns from that catalog: Pattern Category Core Purpose Repository Data Source Abstracts data access behind a collection-like interface Unit of Work Data Source Tracks object changes and commits them as a single transaction These two patterns work beautifully together — and you'll see exactly why with a real-world example. 🛒 The Problem: An E-Commerce Order System Imagine you're building a backend for an online store. When a customer places an order: A new Order is created Each Product 's stock is decremented A Payment record is registered If any of these steps fail midway, the entire operation should roll back — no partial state. This is exactly the problem the Unit of Work pattern solves, and the Repository pattern makes it all cleanly testable. 📁 Repository Pattern Definition "A Repository mediates between the domain and data mapping layers using a collection-like interface for accessing domain objects." — Martin Fowler, PoEAA The Repository acts as an in-memory collection of domain objects. Your business logic never knows if it's talking to PostgreSQL, SQLite, or even a mock list — it just calls .add() , .get() , .list() . Domain Model # models.py from dataclasses import dataclass , field from typing import List from uuid import uuid4 @dataclass class Product : id : str name : str price : float stock : int @dataclass class OrderItem : product_id : str qua

Failures are obvious. Retries are sneaky. When something fails, everyone notices. An alert goes off. A request errors out. Someone starts investigating. Retries are different. They look harmless. Most of the time, they save the system. But sometimes, retries create bigger problems than the original failure. Imagine an API call times out. No problem. The system retries. But what if the first request actually succeeded and only the response was lost? Now the retry creates: duplicate orders repeated emails inconsistent records workflows running twice The failure happened once. The retry multiplied it. Another thing I've seen: One slow dependency causes requests to pile up. Retries start firing. Those retries create even more traffic. Which slows things down further. Which triggers even more retries. Suddenly, the system is spending more effort retrying than doing useful work. Retries also hide problems. A temporary issue gets retried five times and eventually succeeds. Everything looks normal. Meanwhile: latency increases queues grow users experience delays Nothing technically failed. But the system is getting less healthy. What changed for me is that I stopped treating retries as free. Every retry has a cost. It consumes resources. It increases load. And if actions aren't designed carefully, retries can repeat side effects that should only happen once. Now when I build something, I don't ask: "What happens if this fails?" I ask: "What happens if this runs again?" Because in production, things almost always run again. And if the answer is "bad things happen," the retry mechanism isn't helping. It's making things worse. Failures are part of every system. Retries are too. The difference is that failures usually happen once. Retries can turn one problem into hundreds if you don't design for them. This is something we think about constantly at BrainPack when operating long-running workflows across multiple systems. AI and automation layers make retries even more common, wh

Single-model systems are simple. Multi-model systems are powerful. The challenge isn't choosing models — it's designing the architecture that orchestrates them. A multi-model system isn't about having more models. It's about having the right model for the right task at the right time. Architecture patterns Five patterns cover most use cases: Pattern Complexity When to use Tradeoff Single Model Lowest Prototyping, simple tasks Limited capability Sequential Low Multi-step workflows Higher latency Parallel Medium Independent tasks Higher cost Hierarchical High Complex reasoning Complex orchestration Ensemble Highest Critical decisions Highest cost Pick the simplest one that works. Complexity is real, and it compounds. Sequential architecture Process tasks through a chain of models, each specializing in a step. Pattern 1: Pipeline Pipeline pattern — each model's output feeds the next: class ModelPipeline : def __init__ ( self ): self . models = [ { " model " : " qwen2.5-1.5b " , " task " : " classify " }, { " model " : " qwen2.5-7b " , " task " : " extract " }, { " model " : " qwen2.5-32b " , " task " : " reason " }, ] def process ( self , input : str ) -> str : current = input for model_config in self . models : current = self . call_model ( model_config [ " model " ], self . create_prompt ( model_config [ " task " ], current ) ) return current Latency adds up. Three models in sequence means three times the latency. Only use this when each step actually needs a different model. Pattern 2: Router Router pattern — classify the task, route to the specialist: class ModelRouter : def __init__ ( self ): self . classifier = " qwen2.5-1.5b " self . specialists = { " code " : " qwen2.5-coder-7b " , " math " : " qwen2.5-32b " , " creative " : " claude-sonnet-4 " , " general " : " qwen2.5-7b " , } def route ( self , prompt : str ) -> str : task_type = self . classify ( prompt ) model = self . specialists . get ( task_type , self . specialists [ " general " ]) return self . call_m

Building a high-performance Polymarket trading bot requires mastering its unique hybrid architecture:...

Vinay Chella and Akshat Goel discuss the challenges of running traditional CDC across heterogeneous databases during peak order traffic. They explain how Debezium hit limits under high load and share how they built Write-Ahead Intent Log (WAIL) - a custom architecture that utilizes a dumb producer proxy and a smart consumer pattern to cleanly separate the intent from the state payload. By Vinay Chella, Akshat Goel

Adobe is introducing some new capabilities for its Firefly AI assistant, alongside a "reimagined" AI studio that lets you edit and generate new designs from a single interface. The new Firefly experience launching today in private beta is designed to give you "persistent context, reusable assets, and organized workflows" across your projects, according to Adobe, […]

Adobe's plan to stick AI assistants into all of its Creative Cloud suite is now fully underway, with new chatbots now rolling out to its biggest editing and design apps. As part of a public beta launching today, Photoshop, Premiere, Illustrator, InDesign, and Frame.io now each have a bespoke AI Assistant that can be used […]

VS Code 1.123 adds a two-hour delay before auto-updating extensions to newly published versions, creating a revocation window against supply chain attacks. The delay does not apply to trusted publishers like Microsoft, GitHub, and OpenAI. Similar cooldown mechanisms have now spread across pip, RubyGems, npm, pnpm, Yarn, and Bun. By Steef-Jan Wiggers

One of the most common system design interview questions is: "How would you scale a web application from 100 users to 100 million users?" The answer is rarely a single technology. Instead, systems evolve through multiple stages, with each stage solving a specific bottleneck. This article walks through the typical evolution of a scalable system and explains why , how , and when each component is introduced. 1. Single Server Why Start Here? Every application starts simple. In the beginning: Traffic is low Development speed matters more than scalability Infrastructure costs should be minimal What Is It? A single machine handles everything: Frontend Backend Database Users | v Single Server ├── Application └── Database How Does It Work? User sends request. Application processes request. Database stores and retrieves data. Response is returned. Everything happens on one machine. Problem As traffic grows: CPU becomes overloaded Memory becomes insufficient Database competes with application for resources A single server becomes a bottleneck. Interview One-Liner A single server architecture is simple and cost-effective but becomes a bottleneck as traffic and resource usage increase. 2. Application and Database Separation Why Do We Need It? The application and database have different workloads. Application Server: Uses CPU Handles business logic Database Server: Uses memory and storage Handles queries Keeping them together causes resource contention. How Does It Work? Move the database to a separate machine. Users | v Application Server | v Database Server Benefits Independent scaling Better resource utilization Improved performance Example Suppose an e-commerce website receives thousands of requests. The application handles: Authentication Order processing API responses The database handles: Product data Orders User information Separating them prevents one workload from affecting the other. Interview One-Liner Separating the application and database allows each layer to scal

When organizations scale, a simple monolithic architecture often becomes difficult to maintain, deploy, and scale. This is where microservices come into the picture. However, moving to microservices introduces new challenges: How do we migrate from a monolith safely? How do we handle transactions across multiple services? How do we scale read-heavy applications efficiently? Three popular patterns solve these problems: Strangler Pattern – Monolith to Microservices Migration Saga Pattern – Distributed Transaction Management CQRS (Command Query Responsibility Segregation) – Read/Write Scalability 1. Strangler Pattern Why Do We Need It? Most companies cannot shut down a production monolith and rewrite everything from scratch. A complete rewrite is risky because: Development takes a long time. Existing customers are affected. Bugs can impact business operations. Rollback becomes difficult. The Strangler Pattern allows teams to migrate gradually with minimal risk. What Is It? The Strangler Pattern is a migration strategy where new microservices slowly replace parts of a monolithic application until the monolith is no longer needed. The name comes from the strangler fig tree, which gradually grows around another tree and eventually replaces it. How Does It Work? [Insert diagram here showing Client → API Gateway → Monolith + Microservices] Step 1 All requests go to the monolith. Client | v Monolith Step 2 Introduce an API Gateway (or Controller). Client | v API Gateway | v Monolith Step 3 Extract one module into a microservice. Client | v API Gateway |------> Order Service | v Monolith Step 4 Gradually move more modules. Client | v API Gateway |------> Order Service |------> Payment Service |------> Inventory Service | v Monolith Step 5 Eventually remove the monolith completely. Example Consider an e-commerce application. Initially, everything exists inside one application: Monolith ├── Orders ├── Payments ├── Inventory └── Users Over time: Orders become Order Service Payme

Amazon Fulfillment: The Three Tiers of Optimization Amazon processes billions of orders annually through a network of over 175 fulfillment centers globally. To maintain their 1-2 day (or same-day) delivery guarantees, they built a 3-tier optimization architecture: ┌─────────────────────────────────────────────────────────────┐ │ TIER 1: ANTICIPATORY SHIPPING (Long-term — weeks/months) │ │ → ML predicts demand → Moves inventory close to customers │ │ BEFORE they place an order │ ├─────────────────────────────────────────────────────────────┤ │ TIER 2: REGIONALIZATION (Medium-term — days/weeks) │ │ → Partitions the fulfillment network into autonomous zones│ │ → Ensures 70-80% of orders are fulfilled intra-region │ ├─────────────────────────────────────────────────────────────┤ │ TIER 3: CONDOR (Short-term — hours) │ │ → Continuously re-optimizes the fulfillment plan within │ │ a 5-6 hour window before pick-and-pack begins. │ └─────────────────────────────────────────────────────────────┘ Anticipatory Shipping — Shipping Before You Buy A Crazy but Effective Idea Amazon holds a patent (US Patent 8,615,473) describing a system that begins shipping items BEFORE a customer places an order . It sounds like science fiction, but it's a reality. Traditional Model: Customer orders → Warehouse processes → Ships → Delivered (2-5 days) Anticipatory Shipping: ML predicts: "Customers in Region X will buy 200 iPhone 16s in the next 3 days" → Amazon ships 200 iPhones from a central hub to local delivery hubs in Region X → Customer places order → The item is already locally staged → Delivered same-day! ML Model Input Features Input Feature Significance Purchase history What do they buy, and how often? Browsing behavior What are they looking at? Cart abandonment? Wishlists Explicitly desired items Seasonal patterns Winter coats in November, sunscreen in June Regional demographics High-income areas? Young families? College towns? Trending products Items going viral on social media Weathe

By Sergio Colque Ponce — Software Engineering, Universidad Privada de Tacna. Full source code: github.com/srg-cp/design-principles-go When people say "this code is well designed" , they rarely mean it has clever tricks. They usually mean it is easy to change . New requirements arrive every week, and good design is what lets you absorb them without rewriting half the project. In this article I take a small, very common requirement — "send a reminder to the user" — and I show how four classic design principles turn a fragile module into one that is open to change and easy to test. Everything is written in Go , and you can run it yourself from the repository linked above. The requirement We are building the backend of a bank appointment system. When an appointment is created, the user should get a reminder. Today it goes by email . Next month, product wants SMS too. After that, WhatsApp . The pattern is obvious: the list of channels will keep growing. A first (bad) attempt The fastest thing to write is one function that does everything: func SendReminder ( channel , recipient , body string ) error { if channel == "email" { // ... open SMTP, format the email, send it } else if channel == "sms" { // ... call the SMS provider } else if channel == "whatsapp" { // ... call the WhatsApp API } return nil } It works on Monday. But look at what it costs us: Every new channel means editing this function and risking the ones that already work. The function knows about SMTP, SMS providers and HTTP clients all at once: it has many reasons to change . To test the email path you need a real (or faked) SMTP server, because the logic is glued to the transport. This is the design we want to avoid. Let's fix it one principle at a time. 1. Single Responsibility Principle (SRP) A piece of code should have one reason to change . Instead of one function that knows every channel, we give each channel its own type that only knows how to deliver through that channel. Here is the email one: // E

Your AI agent remembered the user's name. Then it forgot what it was doing. Here's the setup: User asks the agent: book the cheapest flight to NYC, search hotels under $150/night, then compare total trip cost. By step 3, the agent calls the LLM with 8,000 tokens of raw conversation history — and still answers as if it's turn 1. You need a memory architecture before this ships. Which one do you pick? A) In-context window only — full conversation stays in the system prompt. Simple. Breaks at ~15 turns or 8K tokens, whichever comes first. B) Vector memory store — embed past turns, retrieve the top-k by semantic similarity at query time. Works great until "NYC flight" pulls a memory about a past NYC trip instead of the current task. C) Episodic memory with summarization — compress old turns into structured event summaries, inject the relevant ones per request. More complex to build. Much harder to confuse. D) Redis session state — structured key-value store, explicit agent reads/writes. Deterministic. Requires the agent to know what to store and when. One of these collapses past 15 turns. One retrieves the wrong context at exactly the wrong moment. One is the right answer for task-oriented agents. Pick A, B, C, or D — and tell me where you've hit this in production. Full breakdown in the comments.

A common way to design an application is to begin with its nouns: User Product Order Payment Then each noun receives the standard architectural starter pack: UserController UserService UserRepository The controller receives users, the service services them, and the repository stores them somewhere responsible. This is noun-oriented architecture : treating every important thing in the domain as if it were automatically a useful software boundary. It works for simple CRUD systems. Unfortunately, most applications eventually do something. The noun becomes a drawer Consider a typical UserService : register() findByEmail() resetPassword() changeAddress() disableAccount() mergeAccounts() assignRole() calculateDiscount() These operations all involve a user. That is approximately where their similarity ends. They have different rules, dependencies, side effects, security concerns, owners, and reasons to change. They live together because User was the nearest available noun when the folders were created. As more behaviour accumulates, UserService becomes the official location for anything vaguely user-shaped. Other components depend on it. It gradually depends on authentication, email, permissions, billing, auditing, and several services added during incidents nobody wishes to revisit. The noun becomes both a dependency of everything and a consumer of everything. The folder remains impressively tidy. Name the capability, not the material A better starting question is not: What things exist in this system? It is: What must this system be capable of doing? That leads to components such as: UserRegistrar PasswordResetter AccountMerger OrderPlacer PaymentRefunder SubscriptionCanceller These are agentive names . They name the component responsible for performing a capability. Compare: UserService with: PasswordResetter UserService tells us which noun is nearby. PasswordResetter tells us what the component is for. That difference produces better architectural questions: What rules

I have just finished writing API Artisan: A Guide to Building APIs with Laravel , and I am giving it away for free. Before you commit to 300-odd pages, let me give you the short version: the tips, patterns, and small decisions that separate an API that technically works from one that developers are genuinely happy to depend on. None of this needs more hardware, a different framework, or a bigger team. It needs you to point your attention at the right things. These are the ones I keep coming back to. Start by measuring the right thing Ask most teams how they know their API is good and you get a single question back: does it work? Can I hit this endpoint and get a response? That question is necessary, and it is nowhere near enough. The question I want you to ask instead is whether your API is liveable with. Can a developer read your docs, understand your auth model, make a successful request, and handle an error without contacting support, trawling a forum, or guessing what a status code is trying to tell them? The gap between "works" and "liveable with" never shows up in a sprint retro, but it shows up everywhere else: in support volume, in integration timelines that overrun, and in the quiet moment a developer decides to build around your API rather than with it. Everything else in the book hangs off one mindset shift: an API is a product. It has users. Treat it as an implementation detail and it will behave like one. It will change without warning when your internals change, and it will be inconsistent because different people wrote different parts on different days with different conventions. Write the contract before the code The natural way to build an endpoint is to write the handler, return some data, and document it afterwards if there is time. It feels efficient, and in the short term it is. The problem is what it produces: a contract that was never designed, only discovered. Let me show you the trap, because I have watched it catch good developers. You have

To build one family’s dream house on a flood-prone Mississippi bayou, AD100 architect Tom Kundig decided the sky’s the limit.

Tech has been encroaching on the family domicile for years—but actor, writer, and satirist Jill Kargman is all in on analog.

From friend compounds and meditation spaces to shaded outdoor areas and rooms just to make coffee, homes are getting even more multipurpose.