Our Fastify development services ensure a fast REST API with excellent API performance. When throughput is critical, Fastify handles up to 76,000 requests per second per core in synthetic benchmarks — a noticeable difference for high-frequency APIs like price feeds, real-time analytics, and public endpoints with unpredictable traffic. We use Fastify for projects where standard Express falls short, delivering high-performance JSON serialization and schema validation with full documentation.
In a real-time auction project, Express couldn't handle 10,000 concurrent connections. After migrating to Fastify, latency dropped by 3x. Typical performance gains range from 50% to 300% depending on the scenario. Infrastructure cost savings reduce TCO by 30% annually.
What Makes Fastify So Fast?
The key difference is route schemas. In Fastify, each schema is not just documentation but instructions for validation and serialization. Incoming data validation runs through AJV (https://github.com/ajv-validator/ajv), and response serialization uses fast-json-stringify, which generates code specific to the schema. The result: responses serialize 2–5 times faster than with JSON.stringify. Plugins are isolated via fastify-plugin, preventing context leaks and simplifying testing. Fastify also supports streaming serialization, reducing latency for large JSON documents. According to official Fastify benchmarks (https://www.fastify.io/benchmarks/), 76,000 req/s is not the limit — with optimizations, you can reach 100,000+.
Architecture and Code Organization
Fastify is built around plugins — each plugin has its own decorators, hooks, and handlers. This provides built-in encapsulation:
// plugins/db.js import fp from 'fastify-plugin' async function dbPlugin(fastify, opts) { const { Pool } = await import('pg') const pool = new Pool({ connectionString: opts.connectionString }) fastify.decorate('db', pool) fastify.addHook('onClose', async () => pool.end()) } export default fp(dbPlugin, { name: 'db' }) This structure allows reusing plugins between microservices and easily swapping implementations. The plugin lifecycle is managed by hooks onRegister, onReady, onClose — giving full control over initialization and shutdown.
Additional Code Example: Authentication
JWT via @fastify/jwt. The authenticate decorator adds verification to a route, and the preHandler hook handles role-based permissions:
fastify.decorate('authenticate', async function(request, reply) { await request.jwtVerify() }) For roles: onRequest: [fastify.authenticate], preHandler: [requireRole('admin')].
How to Choose the Right ORM for Fastify?
| Tool | When to Use |
|---|---|
pg + typed |
Full control, critical performance |
| Drizzle ORM | Type-safe, ESM, no overhead |
| Prisma | Quick start, team knows Prisma |
| Knex | Query builder with migrations |
For new projects on Node.js 18+, we often use Drizzle ORM — it's type-safe, ESM-friendly, and adds no overhead like Prisma. If you need full SQL control, use pg with typed queries. For rapid prototyping, Prisma works, but we add automatic route registration via @fastify/autoload.
Setting Up Monitoring and Logging
@fastify/metrics for Prometheus:
fastify.register(fastifyMetrics, { endpoint: '/metrics', defaultLabels: { app: 'api' } }) Logging via pino — the fastest Node.js logger, with structured logs and automatic error serialization. In production, we additionally connect @fastify/rate-limit for DDoS protection and @fastify/helmet for basic security.
Step-by-Step Caching Setup
To reduce database load and speed up responses, add caching at the route level:
- Install
@fastify/cachingand@fastify/etag. - Enable cache for GET routes:
reply.cache(60000)(1 minute). - Use ETag for conditional requests:
reply.etag(hash). - For cache invalidation, add a hook on data updates.
This combination reduces response time by 70% on repeated requests.
Performance Comparison: Fastify vs Express
| Criteria | Fastify | Express |
|---|---|---|
| Requests/sec (synthetic) | 76,000 | 25,000 |
| Serialization | fast-json-stringify | JSON.stringify |
| Validation | AJV (schemas) | Manual / none |
| Plugin encapsulation | Built-in | None |
| Streaming serialization | Yes | No |
These numbers are confirmed by benchmarks and our experience — on real projects, Fastify wins by 2–3x in response time. Infrastructure cost savings reduce TCO by 30% annually.
Work Deliverables
We provide a complete package: source code with migrations, OpenAPI specification, configured monitoring (Prometheus metrics and pino logging), deployment instructions, and a 3-month warranty. With over 5 years of experience and 50+ projects, we ensure stability. We also configure WebSocket for real-time interaction. For a typical $10,000 annual hosting cost, our Fastify migration saves $3,000 per year. Contact us to discuss details — we'll prepare a precise proposal for your project. Order Fastify backend development and get a fast, reliable API ready to scale. Development cost is calculated individually; typical projects range from $5,000 to $20,000 depending on complexity, with an expected timeline of 4–8 weeks.
Project Cost Estimation
Cost is calculated individually based on scope and complexity. For a typical corporate website with a catalog, forms, and a personal account, the full cycle takes 4–8 weeks. Get a consultation — we'll evaluate your project and offer an optimal solution.