Last updated: May 2026 Microservices are an architectural style where an application is built as a collection of small, independently deployable services that communicate over the network. Each service owns a single business capability and its own data, allowing teams to develop, deploy, and scale parts of the system independently. The pattern powers most modern web-scale software — Amazon, Netflix, Uber, Etsy, and Spotify all run on microservices. This guide covers what microservices are, how five well-known companies use them in production, the benefits and trade-offs, how to build a microservices architecture step by step, and how the rise of AI agents and the Model Context Protocol is changing what microservice teams need to plan for in 2026 and beyond. A microservices architecture breaks a single, large application into a network of small services. Each service: The opposite of microservices is the monolith: a single application with one codebase, one database, and one deployment unit. Monoliths aren't inherently bad — they're often the right starting point — but they become harder to evolve as teams and feature surface grow. The clearest way to grasp microservices is to compare them directly to the monolithic pattern they typically replace. The clearest way to understand the pattern is to see how five well-known companies actually use it. Each migration was driven by the same underlying problem — a monolith that had outgrown its team — but the path each took looked different. Amazon was one of the earliest companies to formalise the microservices pattern. By 2001, the original Obidos monolith that powered amazon.com had become a deployment bottleneck — every code change required coordinating across hundreds of engineers, and a single bad commit could ground the whole site. The fix was a now-famous internal mandate from Jeff Bezos: every team would expose its capabilities as a service over the network, every service would be built as if it would one day be exposed externally, and there would be no other form of inter-process communication. The result was the architecture that eventually became AWS — the same internal services Amazon built to fix its own monolith are what it now sells to the rest of the industry. What Amazon did: Netflix's microservices migration started in 2008 after a database corruption incident took DVD shipments offline for three days. The team concluded that the monolithic infrastructure couldn't deliver the reliability and scale needed for streaming, and embarked on a multi-year migration to AWS and a microservices architecture. By 2012, Netflix was running more than 500 microservices on AWS, handling more than a billion API calls per day. Today the number is in the thousands. Netflix open-sourced much of the supporting infrastructure — Eureka (service discovery), Hystrix (circuit breaking), Zuul (API gateway), and the Chaos Monkey resilience-testing framework — which became the de-facto reference stack for microservices in the 2010s. What Netflix did: Uber started life as a monolithic Python and Node.js application backed by a PostgreSQL database. By 2014, with operations expanding into hundreds of cities, that architecture was breaking down: a single bug could take rides offline globally, deploys took hours, and adding a new feature required understanding the whole codebase. Uber's response was a multi-year migration to a service-oriented architecture, eventually growing to more than 2,200 microservices. The architecture introduced its own problems — the team coined the phrase "microservice sprawl" to describe what happens when service count grows faster than tooling — and Uber later published several engineering posts about consolidating chatty services and standardising on a smaller, well-defined platform layer. What Uber did: Etsy's path is the counterexample that proves microservices aren't always the answer. While Amazon, Netflix, and Uber were aggressively decomposing into services, Etsy famously stayed closer to a "monolith-with-services" pattern through the 2010s, focusing on continuous deployment, feature flags, and tight engineering discipline rather than service decomposition. Etsy still runs many independent services for specific concerns — search, recommendations, payments — but kept the core e-commerce flow in a single PHP application that all engineers contribute to, deployed dozens of times a day. The lesson: microservices aren't a checkbox. The right architecture is the one that matches your team size, deployment velocity, and product complexity. What Etsy did: Spotify's microservices story is often discussed alongside its organisational design — the famous "squad, tribe, chapter, guild" model where small autonomous squads own services end-to-end. By 2026, Spotify operates more than 1,500 microservices across data, recommendation, playback, and ads platforms. The technical architecture is less novel than the organisational one. Spotify's contribution to the industry is showing how to scale the people side of microservices — keeping teams small, autonomous, and aligned with service boundaries — which turns out to be at least as hard as the technical decomposition itself. What Spotify did: The decision to adopt microservices is usually triggered by a constraint — deploys are slow, teams are stepping on each other, scaling the whole monolith is expensive — rather than a green-field choice. Here's the rough playbook most teams follow. The reasons companies migrate from monoliths to microservices have stayed consistent for two decades: Microservices solve specific problems but introduce new ones in return. The teams that succeed go in clear-eyed about the trade-offs: The biggest shift to microservices architecture in the last two years isn't another framework — it's who's calling the services. AI agents built on large language models now make a growing share of API calls, fetching data, invoking tools, and chaining requests across services on behalf of users. This creates a new layer in the stack. The Model Context Protocol (MCP), introduced by Anthropic and rapidly adopted by other LLM providers, is the emerging standard for how AI models discover and call APIs at runtime. An MCP server exposes microservice endpoints as tools the model can read and invoke; an MCP client (like Claude or ChatGPT) consumes those tools. That changes a few things for any microservices team: The piece of infrastructure handling that data-access layer is the AI Data Gateway — a secure intermediary between enterprise data sources and AI systems. Where a traditional API gateway handles authentication, rate limiting, and routing for human-driven traffic, an AI Data Gateway adds AI-aware controls: identity passthrough, deterministic query enforcement, prompt logging, content filtering, and field-level data governance for agent traffic. For microservices teams already running an API gateway, an AI Data Gateway sits as a complementary layer — purpose-built for the specific risks and traffic patterns of AI consumption. See What is an AI Data Gateway for the full architecture, and Zero Trust for LLMs for how the security model works in practice. DreamFactory's foundational capability is instant REST API generation: connect a database (Oracle, SQL Server, PostgreSQL, MySQL, Snowflake, Databricks, MongoDB — 40+ supported), and the platform auto-generates a fully documented, role-protected REST API in minutes, with no code written. The platform has been doing exactly this for over a decade. Authentication (Microsoft Entra ID, OAuth 2.0, OpenID Connect, SAML 2.0, LDAP, Active Directory, API keys), role-based access control (per table, endpoint, and HTTP verb), rate limiting (per user, role, or service), audit logging (every call captured with calling user, timestamp, and payload), and OpenAPI documentation are built in. Server-side scripting in PHP, Python, or Node.js handles custom business logic. The AI Data Gateway is the newer chapter — a built-in MCP server that exposes the same auto-generated REST API to AI agents (Claude Desktop, Claude Code, ChatGPT, Cursor, Windsurf). The company's framing: "turn your database into an auditable, governed API layer for AI." The core principle is data stays put — keep your systems of record intact, generate a governed API on top, and let AI agents query through that layer rather than receiving raw data extracts. In DreamFactory's MCP tutorial, CTO Kevin McGahey demonstrates the full flow: database credentials, one MCP call, auto-generated API, read-only role, API key — and Claude Code building a working dashboard in minutes. DreamFactory deploys via Linux installer (Ubuntu, Debian, CentOS, RHEL, Fedora), Windows (IIS or Apache), Docker, Kubernetes via official Helm chart, or NPX quick install. Air-gapped deployment is fully supported — as used by the Vermont Agency of Transportation to expose an Oracle database and a 1970s-era IBM S370 mainframe through a unified API layer. DreamFactory's customers include ExxonMobil, Toyota, Saint-Gobain, PPG, Deloitte, Google Cloud, AkerBP, Netgear, Miller Industries, the National Institutes of Health, the Vermont Agency of Transportation, D.A. Davidson, and Pillsbury Law — spanning energy, automotive, industrial, finance, government, healthcare, and legal. G2 rates the product 4.7 with badges for "Easiest to Use," "Fastest Implementation," and "Best ROI." See the DreamFactory AI page or request a demo. A microservices architecture is a way of building applications as a collection of small, independently deployable services, each owning a single business capability and communicating with the others over the network — usually via REST APIs, gRPC, or message queues. Each service has its own data store, its own deployment lifecycle, and can be written in a different language from the others. Amazon, Netflix, Uber, Etsy, and Spotify are five of the most-cited microservices examples. Amazon broke its monolith apart in the early 2000s, Netflix migrated through 2008-2012, Uber moved off its monolith starting around 2014, Etsy adopted a hybrid model, and Spotify built its squad-and-tribe organisational model around microservice ownership. An API is the interface a service exposes — the set of endpoints other software can call. Microservices describes the architectural pattern of building an application out of many small services, each typically exposing its own API. Every microservice has APIs, but not every API is part of a microservices architecture. Most microservices communicate via synchronous HTTP/REST or gRPC for direct request-response calls, and asynchronous message queues (Kafka, RabbitMQ, AWS SQS) for event-driven workflows. Service meshes like Istio or Linkerd handle service-to-service authentication, retries, and observability across the network. Independent deployability, language and framework agnosticism, improved fault isolation (one service failing doesn't take the whole app down), team autonomy (small teams can own a service end-to-end), and elastic scaling (scale only the services under load instead of the whole monolith). For data-heavy applications, microservices also make it easier to apply per-service security, compliance, and audit controls. Operational complexity, network latency, distributed-system failures, harder debugging across services, the need for sophisticated monitoring and tracing, and the up-front cost of building infrastructure (CI/CD, service discovery, observability, an API gateway). Microservices also typically require organisational changes — DevOps practices, on-call rotations per service, and product teams that align with service boundaries. AI agents built on large language models call microservices through tools exposed via the Model Context Protocol (MCP). An MCP server wraps one or more microservice endpoints with semantic descriptions; an MCP client (Claude, ChatGPT, custom agents) reads the available tools and invokes them at runtime. For data access specifically, an AI Data Gateway sits between the agent and the underlying microservices to enforce identity passthrough, deterministic queries, and field-level redaction. A microservices API gateway is the front door to a microservices architecture. It handles cross-cutting concerns — authentication, rate limiting, request routing, response shaping, observability — so each individual microservice doesn't have to. Common examples include Kong, AWS API Gateway, Apigee, and DreamFactory.Quick summary
What are microservices?
Microservices vs monolithic architecture
Dimension
Monolithic architecture
Microservices architecture
Codebase
Single repository, single deployment unit
Many repos (or a monorepo with clear service boundaries), each independently deployable
Database
One shared database
One database per service (or per logical bounded context)
Deployment
Whole application redeployed for any change
Each service deploys independently, often many times per day
Scaling
Scale the entire app — even if only one feature is hot
Scale only the services under load
Failure mode
One bug can take down the whole app
Failures can be isolated to a single service
Team structure
One large team or many teams sharing one codebase
Small teams own services end-to-end (build, run, on-call)
Operational complexity
Lower — one process to monitor
Higher — distributed system, network failures, observability is essential
Best for
Small teams, early-stage products, simple domains
Large engineering orgs, high-scale systems, multi-team product surface
Real-world microservices examples
1. Amazon
2. Netflix
3. Uber
4. Etsy
5. Spotify
How to build a microservices architecture
Benefits of microservices
Trade-offs and challenges
Microservices in the AI era
How DreamFactory fits in
Frequently asked questions
What is a microservices architecture?
What's an example of a company using microservices?
What's the difference between microservices and APIs?
How do microservices communicate with each other?
What are the main benefits of microservices?
What are the trade-offs of microservices?
How do AI agents call microservices?
What's a microservices API gateway?
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Terence Bennett, CEO of DreamFactory, has a wealth of experience in government IT systems and Google Cloud. His impressive background includes being a former U.S. Navy Intelligence Officer and a former member of Google's Red Team. Prior to becoming CEO, he served as COO at DreamFactory Software.