# Nexora | Node.js API & Backend Development > Nexora builds Node.js backends and APIs with clear request handling, background tasks and dependency controls suited to your application. Canonical page: https://www.nexoraesrd.com/technologies/nodejs-backend-integration/ Language: English Nexora ESRD LLP · Application Development Technologies & Platforms # Node.js API & Backend Development A backend connects user actions with the data and services behind them. We develop Node.js applications around clear contracts and predictable behaviour, including what happens when an external service responds slowly or fails. [Discuss your project ↗](https://www.nexoraesrd.com/contact/?service=software) ## Plan Node.js API requests and responses We map the actions the backend supports and the permissions needed for each one. Validation, response formats and error codes are agreed with the calling application. Sensitive checks remain on the server, and logs are designed to support investigation without recording unnecessary private information. ## Separate requests from longer work Imports, notifications and third-party processing do not always belong inside a user’s request. We identify work that needs a queue or background job, then define status, retries and duplicate handling. Resource limits and timeouts help prevent one demanding operation from disrupting unrelated tasks. ## Control the application’s dependencies Package choices and external integrations become part of the product’s maintenance needs. We review them alongside configuration and deployment. Tests cover important workflows and failure responses, while the handover explains how to run the application, manage settings and investigate a failed task after release. ## Project deliverables - Backend and integration contracts - Node.js services and job handling - Validation and failure-path checks - Release and operating instructions ## Service questions and answers ### Should sending notifications happen inside a user’s request? Only if the response time and failure behaviour make that appropriate. Longer or unreliable work may need a recorded job and a separate worker. We agree what the user sees while delivery is pending and how retries work, so the interface does not report a completed notification merely because a request was accepted. Explore related services [Separate notification delivery from an event](https://www.nexoraesrd.com/nexora/iot-data-alerts/) ### How should the backend treat duplicate webhooks or retry requests? We identify the operation or event before applying changes and record enough state to recognise a repeat. The exact rule depends on the external system and the action being performed. Tests include duplicate and out-of-order events, so retry behaviour does not accidentally create two records or repeat a consequential action. Explore related services [Define repeatable integration behaviour](https://www.nexoraesrd.com/services/api-and-system-integration/) ### Can permission checks stay entirely in the JavaScript frontend? No. The backend must verify access for the requested record and action, because callers can send requests without using your interface. We align frontend feedback with those server rules. Checks need to cover ordinary reads and writes as well as exports, background jobs and any customer-specific data boundaries. Explore related services [Align interface states with backend rules](https://www.nexoraesrd.com/technologies/javascript-web-experience-engineering/) ### What makes a Node.js package update ready for release? We review the affected dependencies and check the workflows they support, rather than relying only on a successful installation. Changes can affect request handling, background processing or build output. The release record should include relevant checks and a recovery approach, with deployment configuration kept separate from ordinary source files. Explore related services [Prepare repeatable application releases](https://www.nexoraesrd.com/services/release-and-operations-engineering/) ## Discuss your project Tell us what you want to build. We'll help you find a clear way forward. [Discuss your project ↗](https://www.nexoraesrd.com/contact/?service=software) Explore the wider service [Software & Web Development ↗](https://www.nexoraesrd.com/services/software-web-development/) [Discuss your project ↗](https://www.nexoraesrd.com/contact/?service=software) ## Related services ### IoT Data Processing & Alert Workflows Process IoT data with Nexora through validation, useful history and alert workflows with clear recipients, acknowledgement and follow-up responsibilities. [Explore this service](https://www.nexoraesrd.com/nexora/iot-data-alerts/) ### API Development & System Integration Nexora develops APIs and system integrations with defined data contracts, access controls, retry handling and documentation for connected applications. [Explore this service](https://www.nexoraesrd.com/services/api-and-system-integration/) ### JavaScript Web Development Services Create JavaScript web applications with Nexora. Plan user interactions, manage application state and keep frontend delivery light and maintainable. [Explore this service](https://www.nexoraesrd.com/technologies/javascript-web-experience-engineering/) ### DevOps & Release Engineering Services Nexora helps improve builds and deployments with repeatable processes, useful monitoring and clear release, recovery and operating responsibilities. [Explore this service](https://www.nexoraesrd.com/services/release-and-operations-engineering/)