REST + GraphQL APIs
NestJS or Fastify backends with OpenAPI 3.1, GraphQL Yoga or Apollo Server, strict TypeScript, Zod or class-validator at the boundary. Multi-tenant SaaS schemas, RBAC, row-level security.
Services
Node.js Development Services for US & EU SaaS, Fintech and Real-Time Products
Senior Node.js engineering for funded scale-ups: TypeScript-first NestJS and Fastify backends, event-driven services on AWS and GCP, real-time gateways for chat, trading and IoT, and LTS-track upgrades from Node 16/18 onto Node 20 and 22 without breaking your SLA. We ship production code from week one — not architecture decks. Dedicated teams from 12,000 EUR/month, project sprints from 25,000 EUR.
Node.js wins when your product is event-driven, latency-sensitive, or has to share a TypeScript type system between server and browser. We use it where it earns its place: SaaS APIs that need 5 to 50 ms p95, fintech orchestration sitting on top of Kafka and Postgres, real-time gateways (Socket.IO, Server-Sent Events, native WebSocket) for chat, trading dashboards and connected hardware, and BFF layers in front of Next.js, React Native or Flutter clients. Our engineers average 8+ years on the V8 runtime and have shipped Node services that survived peak loads of 40k req/s — including the cold-start optimisation on AWS Lambda and Cloud Run that the docs never mention. We are GDPR-aligned · ISO 27001 ready · SOC 2 Type II in progress.
What we build with Node.js
Event-driven services
Kafka, Redis Streams, RabbitMQ, AWS SQS/SNS and EventBridge consumers and producers. Idempotent handlers, outbox pattern, exactly-once semantics where the business needs it.
Real-time gateways
Socket.IO clusters with Redis adapter, native WebSocket on uWS, SSE for one-way feeds. Horizontal scaling on Kubernetes with sticky sessions and graceful shutdown.
Auth + multi-tenancy
Auth0, WorkOS, Clerk or Keycloak integration. JWT and PASETO, refresh-token rotation, OAuth 2.1, SAML for enterprise, OIDC for B2B SSO. SCIM provisioning when the customer asks.
Background workers
BullMQ on Redis, Temporal, AWS Step Functions, Inngest. Long-running jobs, scheduled tasks, retries with backoff, dead-letter queues and observable progress.
Node modernisation
Migrating Node 14/16/18 to LTS 20/22, CommonJS to ESM, Express to Fastify or NestJS, plain JS to TypeScript strict, and on-prem to AWS Fargate or Cloud Run without rewriting the world.
Stack and tooling
Node.js 20 / 22 LTS
TypeScript 5
NestJS
Fastify
Express
Hono
GraphQL Yoga
Apollo Server
Prisma
Drizzle ORM
TypeORM
PostgreSQL
MongoDB
Redis
Kafka
BullMQ
Temporal
AWS Lambda
Cloud Run
Kubernetes
How an engagement runs
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01
Discovery
1–2 weeks: read the existing repo, map traffic and latency requirements, decide on Fastify vs NestJS, decide on Prisma vs Drizzle, and produce a written architecture decision record before any code lands.
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02
Foundation
Sprint 1–2: monorepo scaffold (pnpm + Turborepo or Nx), CI/CD on GitHub Actions, OpenTelemetry, structured logging with pino, Datadog or Grafana stack, blue/green deploys.
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03
Build
Two-week sprints, trunk-based, feature flags via Unleash or LaunchDarkly, contract tests against your existing services, load tests with k6 against agreed SLOs before each release.
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04
Operate
On-call rotation handoff (PagerDuty / Opsgenie), SLO dashboards, error-budget burn-rate alerts, quarterly cost review of AWS / GCP spend with concrete cut recommendations.
Engagement models
Dedicated team
2–6 senior engineers embedded in your roadmap, daily standup in your channel, your repo, your CI, your on-call. Best for product roadmaps with a 6+ month horizon. From 12,000 EUR/month.
Project sprint
Fixed-scope, fixed-budget delivery: discovery + MVP + first production release. Best for new product lines, validated PoCs that need hardening, and stand-alone modules. From 25,000 EUR.
Staff augmentation
One or two senior engineers slotted into your existing squad, your stand-up, your process. Best for filling a known capability gap without disturbing team structure. From 7,500 EUR/month per engineer.
Three-month minimum on all tiers, month-to-month thereafter with 30 days notice. NDA, DPA, and IP assignment signed before kickoff.
Selected related work
Social Media · Consumer Tech
JoyJet
Production social platform — App Store + Google Play, live across the US and EU — with geo Radar, encrypted messaging and a virtual economy.
LegalTech · Mobile · CRM
Signatory Pro
Native iOS and Android e-signature clients with a Symfony + React CRM for a cross-border law firm — KYC onboarding and a defensible evidence trail for US & EU matters.
Logistics · Last-mile · Mobile
xRouten
Android + iOS refactor and rebuild for a German last-mile logistics operator — multi-point route planning, real-time driver tracking and in-app invoicing live in the EU.
Why US & EU teams pick YuSMP for Node.js development
GDPR-aligned · ISO 27001 ready · SOC 2 Type II in progress · HIPAA-capable · CCPA-acknowledged
Senior engineers, not body shop
Every engineer on your account has 6+ years of production Node.js experience. No bait-and-switch from the senior who sold the deal to a junior who actually ships.
CET workday + US overlap
CET-aligned squads with a guaranteed 9 AM–1 PM ET overlap for US clients — four hours of synchronous work per day, async docs for the rest. No 3 AM standups for anyone.
Compliance-fluent delivery
GDPR DPAs, SOC 2 Type I/II readiness, HIPAA controls for US healthtech, CCPA notices, EU AI Act for AI features. The compliance work is built into the sprint, not bolted on at audit time.
For regulated workloads we work directly with your auditor or fund's technical advisor and prepare evidence to the standard the reviewer expects — not the standard a generalist consultant assumes.
Frequently asked questions
Why pick Node.js over Go, Python or .NET for our backend?
Node.js wins when your team already writes TypeScript on the frontend and you want one type system end-to-end, when you have heavy I/O concurrency (thousands of WebSocket clients, lots of fan-out HTTP), and when developer velocity matters more than raw CPU throughput. Pick Go for CPU-bound services and binaries you want to ship statically. Pick Python or .NET when the ecosystem (ML, Office, Windows enterprise) decides for you. We will tell you honestly during discovery if Node is the wrong call — we run polyglot teams and have no incentive to push you the wrong way.
Which Node.js version and framework do you standardise on in 2026?
Node.js 22 LTS is our default for new builds (active LTS until October 2027), with Node 20 LTS for clients still on it. We use TypeScript 5.6+ in strict mode with noUncheckedIndexedAccess. Framework default is NestJS for opinionated multi-team monorepos and Fastify for high-throughput stand-alone services. Express still ships for legacy maintenance — we do not force migration unless there is a real reason. ORM default is Prisma for product teams and Drizzle for performance-critical paths.
Do you handle EU data residency and GDPR for Node.js services?
Yes. Default region is AWS eu-central-1 or eu-west-1, GCP europe-west3 or europe-west1, Azure germany-westcentral on request. We deploy with Terraform modules that pin region and forbid replication outside the EU. PII columns are encrypted at the application layer with AWS KMS / GCP KMS keys held in the customer's account. We sign DPAs aligned to GDPR Article 28, run DPIAs for high-risk processing, and document Article 30 records of processing. For US customers we mirror the same stack in us-east-1 / us-west-2 with CCPA notices and HIPAA controls when needed.
How do you handle real-time scale — tens of thousands of WebSocket clients?
Socket.IO with the Redis adapter on Kubernetes is our default up to ~50k concurrent connections per cluster, sticky sessions on the ingress, graceful shutdown, and a custom heartbeat that catches dead NAT'd mobile clients in under 30 seconds. Past 50k concurrent we move to uWebSockets.js or a Go gateway in front of the Node business logic. We have shipped a 120k-concurrent live-trading dashboard on this pattern with p95 broadcast latency under 80 ms across EU and US edge.
Can you migrate our legacy Express + JavaScript monolith to NestJS + TypeScript without downtime?
Yes, this is one of our most common engagements. We run the strangler-fig pattern: stand up a NestJS app behind the same load balancer, move one module at a time, share the database during transition, and use feature flags to cut traffic over per endpoint. We add TypeScript incrementally (allowJs, then strict per directory). Typical 80k-LOC monolith takes 4 to 6 months to fully migrate with no customer-visible downtime and no feature freeze.
What does pricing look like for a Node.js dedicated team or project sprint?
Dedicated teams start at 12,000 EUR/month for a 2-engineer pod (typically 1 senior + 1 mid plus fractional tech lead and DevOps). Standard squads are 4–6 engineers at 28,000–42,000 EUR/month with full QA, DevOps and PM coverage. Fixed-scope project sprints (discovery + MVP + first production release) start at 25,000 EUR. All engagements include CET workday with 9 AM–1 PM ET overlap for US clients, NDA + DPA + IP assignment signed before kickoff, and month-to-month after the initial three-month minimum.