Node.js development company
We build Node.js backends that respect the event loop: REST and GraphQL APIs, WebSocket services, queue workers and integrations, written in TypeScript and shipped with load tests, tracing and a dependency policy your security team can audit.
- Senior engineers · IST + EST overlap
- NDA on day 1
- 24-hour reply
- Projects shipped
- 50+
- Code ownership
- 100%
- Client rating
- 4.8/5
- First reply
- 24h
Node.js services designed around the event loop
Our work as a Node.js development company centers on APIs, real-time services and integration layers for products where many concurrent connections spend most of their time waiting on databases, third-party APIs or sockets. That is the workload Node.js handles well, because its single-threaded event loop and non-blocking I/O keep large numbers of idle connections cheap. It handles CPU-heavy work badly: image processing, large JSON transforms or synchronous crypto in a request handler stall every other user on that process. Krapton engineers design around this from the start, moving heavy computation to worker threads or separate services, running background jobs through BullMQ on Redis, and watching event-loop delay as a first-class metric. New services are written in TypeScript on Fastify, NestJS or Express 5, with Prisma or Drizzle for data access, pino for structured logs and OpenTelemetry for traces. Every service ships with health checks, graceful shutdown on SIGTERM so deployments do not drop in-flight requests, and container images that run as a non-root user.
Node.js development services
REST and GraphQL APIs
Fastify, NestJS or Express 5 services with schema-validated requests, OpenAPI or GraphQL schemas, cursor pagination, rate limiting and authentication through OAuth 2.0, JWT or session cookies.
Real-time and WebSocket services
Chat, live dashboards and collaborative features on Socket.IO or ws, scaled across instances through a Redis adapter, with backpressure handling and reconnection logic tested under load.
Queues and background workers
BullMQ or cloud queues for emails, webhooks, report generation and retries, with idempotent job handlers, dead-letter handling and dashboards showing stuck or failing jobs.
Integration and BFF layers
Backend-for-frontend services that aggregate payment, CRM and internal APIs for web and mobile clients, with timeouts, retries and circuit breakers so one slow provider does not cascade.
Performance and memory fixes
Diagnosing event-loop stalls, memory leaks and slow endpoints with CPU profiles, heap snapshots in Chrome DevTools, flame graphs and APM traces, then fixing the code paths responsible.
Node.js version upgrades
Moving services off end-of-life Node.js lines to a current LTS release, replacing deprecated APIs, converting CommonJS to ES modules where it pays, and updating native addons.
Why teams choose Krapton for Node.js
Senior engineers, fixed scope, and code you own — the things agencies promise and rarely deliver.
Supply chain treated seriously
Dependencies are pinned through lockfiles, new packages are reviewed for maintainers and install scripts, and CI flags known vulnerabilities, because npm compromises usually arrive through transitive packages.
Input validated at every edge
Fastify’s JSON Schema validation or Zod guards every route and job payload, and config loads fail at startup when a required environment variable is missing.
Right tool, even if not Node.js
When a workload is CPU-bound, such as video transcoding or heavy numeric work, we recommend Go, Rust or a managed service for that piece rather than forcing it into Node.js.
Tests that hit real dependencies
Integration tests run against PostgreSQL and Redis in Testcontainers or Docker Compose, with Supertest exercising HTTP routes, so mocks do not hide query or serialization bugs.
How a Node.js project runs with Krapton
01
Workload profiling
We look at request patterns, concurrency, CPU-heavy paths and integrations to confirm Node.js fits, and identify anything that belongs in a worker or another runtime.
02
Service and data design
Framework choice, module layout, database schema, queue topology and API contracts are documented, along with error-handling and logging conventions every service follows.
03
Build and load test
Features ship with unit and integration tests, and k6 or Artillery load tests check latency and event-loop delay against agreed targets before release.
04
Deploy and operate
Containerized releases on Kubernetes, ECS or serverless platforms, with health checks, autoscaling rules, OpenTelemetry dashboards and runbooks for memory growth and stuck queues.
The Node.js stack we build with
Node.js development: questions answered
When should a Node.js development company recommend against Node.js?
When the core workload is CPU-bound. Video encoding, large-scale numeric computation, heavy image processing or long synchronous parsing block the event loop and degrade every request on the process. Worker threads help for occasional heavy tasks, but sustained compute is better served by Go, Rust, Java or a managed service. Node.js remains a strong choice for I/O-heavy APIs, real-time features and integration layers around those components.
Express, Fastify or NestJS: which Node.js framework should we use?
It depends on team size and how much structure you want. Express 5 has the largest ecosystem and suits small services and teams that already know it. Fastify offers built-in JSON Schema validation, a plugin system and lower overhead per request. NestJS adds modules, dependency injection and decorators, which helps larger teams keep a consistent architecture, at the cost of more abstraction and a steeper learning curve.
How do you scale a Node.js backend under growing traffic?
Horizontally, after removing the bottlenecks that more instances would only multiply. We first check event-loop delay, database query times and connection pool limits, then run multiple stateless instances behind a load balancer with autoscaling on CPU and latency signals. Session data and WebSocket fan-out move to Redis, slow work moves to queues, and caching sits in front of expensive reads. The cluster module is rarely needed once containers handle process count.
How do you keep a Node.js codebase secure and up to date?
Through dependency hygiene, runtime upgrades and secure defaults. Lockfiles are committed, Dependabot or Renovate raises update pull requests, and CI fails on known critical vulnerabilities. Services run on a supported LTS release and are upgraded before end-of-life. Code avoids eval and dynamic require on user input, uses parameterized queries, sets security headers with Helmet, and keeps secrets in a managed vault rather than committed .env files.
What shapes the cost of a Node.js project?
Integrations and real-time requirements shape it more than raw endpoint count. Each third-party API brings authentication, error handling, retries and test fixtures; WebSocket features add scaling and reconnection work; and queues add monitoring and idempotency. Data migration from an existing system, compliance needs, expected traffic and infrastructure setup round out the picture.
Ready to build? Tell us what you have in mind.
Send a short brief and a senior engineer will reply within one business day with next steps — no sales fluff.