What API technologies does FlowMind use?
We build with Node.js (Express, Fastify), Python (FastAPI, Django), and deploy to AWS or Vercel. We deliver OpenAPI documentation with every API.
Backend · FlowMind
API Development Agency — REST, GraphQL & Backend Systems
FlowMind is an API development agency for US and UK product teams that need production-grade REST and GraphQL APIs, not prototype routes. We deliver Node.js API development with Express, Fastify, and Hono; FastAPI development agency–grade Python services when ML or data science sits beside your core app; and GraphQL API development UK and US clients can scale with federation-ready patterns. Every engagement ships with authentication, versioning, observability hooks, and OpenAPI or schema docs your mobile and web clients can trust.
Whether you are unifying legacy SOAP endpoints behind a modern facade or launching a greenfield BFF for a Next.js client, we align error models, pagination contracts, and idempotency keys with how your frontend and partners actually consume data. Security defaults include JWT and OAuth2 where appropriate, secrets in environment managers, and structured audit trails for privileged operations — so compliance reviews do not stall your launch.
REST API Development
We design resource-oriented REST APIs with consistent status codes, pagination, filtering, and idempotent writes where finance and inventory are involved. Controllers are thin; domain logic is testable. We ship OpenAPI 3 specs, Postman collections, and Jest or Pytest suites so regressions surface in CI. Redis backs rate limiting and sessions when needed. Deployments target Docker on AWS ECS or Lambda for spiky workloads — always with structured logging and request IDs. Deliverables: documented endpoints, staging environment, runbook for deploys, and handoff session for your engineers.
GraphQL API Development
GraphQL fits products with diverse clients and nested data needs. We model schemas to avoid N+1 disasters, add DataLoader-style batching, and enforce auth at the resolver layer. Federation can split ownership across teams when you are ready. We document operations, ship GraphQL Playground or Sandbox in non-prod, and protect production with complexity limits and persisted queries where appropriate. GraphQL API development UK and US engagements include performance profiling before launch — latency budgets are explicit.
Third-Party API Integrations
We integrate Stripe for payments, Twilio and SendGrid for comms, HubSpot and Salesforce for CRM sync, and Shopify Admin APIs for commerce automation. Webhooks are verified with signatures, retried with exponential backoff, and dead-lettered when vendors misbehave. OAuth2 and API keys are stored in secrets managers — never in repos. You receive integration diagrams and failure-mode notes so on-call is not guessing.
API Authentication & Security
JWT access and refresh flows, OAuth2 for partner integrations, scoped API keys for server-to-server, and role-based checks at the edge and service layer. We apply OWASP-minded validation, input sanitization, and audit logs for sensitive mutations. Rate limits protect abuse; CORS and CSRF policies match your frontends. Security is not an appendix — it is in the acceptance criteria for every route.
API Documentation & Testing
OpenAPI / Swagger for REST; schema-first GraphQL SDL with changelog. Contract tests run against mocks so mobile teams can parallelize. We prefer example payloads that mirror real CRM and catalog data — not toy JSON. FastAPI development agency clients get automatic OpenAPI from type hints when Python is the stack; Node services get zod or Joi validation mirrored in docs.
Backend Architecture & Microservices
Monolith-first until metrics justify splits. When we decompose, boundaries follow domain seams — not framework fashion. Message queues (SQS, BullMQ) decouple async work; PostgreSQL remains source of truth for transactional state. We document deployment topology in Terraform or Pulumi snippets when infra is in scope. You always know what owns what.
Frequently asked questions
Do you integrate third-party APIs?
Yes. We integrate Stripe, Twilio, SendGrid, HubSpot, Salesforce, Shopify, and custom APIs. We handle authentication, error handling, retry logic, and webhook processing.
How long does API development take?
Simple REST APIs with 5-10 endpoints: 1-3 weeks. Complex GraphQL APIs with auth and integrations: 3-8 weeks. We provide a detailed estimate after a free discovery call.
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