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Backend development

Custom software: backends, APIs and integrations that connect your business

Backends and APIs with Node.js, NestJS and GraphQL, plus integrations with other systems, on AWS serverless or containers.

You need your systems to talk to each other, to expose your data to an app, or to build the backend of a new product. I build REST and GraphQL APIs with Node.js, TypeScript and NestJS, integrate third-party services through APIs and webhooks, and deploy them on AWS with Lambda or containers, with automated tests and documentation from day one.

  • Node.js
  • NestJS
  • GraphQL
  • AWS serverless
  • Integrations
  • Backend diagram: web and mobile clients call a REST or GraphQL API, backed by NestJS services and AWS Lambda functions connected to databases, third-party APIs and queues.

Packages

Three levels of scope. Pricing is quoted for your case.

Basic

A single integration or endpoint, for example connecting two systems through an API or a webhook.

Deliverables

  • Integration or endpoint in Node.js and TypeScript
  • Input validation and error handling
  • Automated tests
  • Usage documentation
  • Estimated delivery: 5 days
  • 1 revision
Request a quote for this package: Basic

Standard

A complete REST or GraphQL API with NestJS, deployed on AWS.

Deliverables

  • Everything in Basic
  • Data model and database
  • Authentication and authorization
  • API documentation
  • Deployment on AWS (Lambda or containers)
  • Estimated delivery: 15 days
  • 2 revisions
Request a quote for this package: Standard

Premium

The backend of a product, with several services, events and queues, and everything needed to run it.

Deliverables

  • Everything in Standard
  • Event-driven architecture with queues
  • Logs, metrics and alerts
  • CI/CD pipeline
  • A handover session with your team
  • Estimated delivery: 30 days
  • 3 revisions
Request a quote for this package: Premium

Related work

Past projects where I did this kind of work. Clients stay anonymous for confidentiality.

Open-source integration platform · United States

Automated quality checks for a catalog of thousands of integrations

Node.js developer · 4+ years

Problem
The platform publishes components (sources and actions) that connect to more than 3,000 apps. When a change affected a component, directly or through shared dependencies, it was easy to forget to bump its version, and errors in integrated apps were hard to spot among so many.
Solution
I built a GitHub Action that walks the dependency tree of the changed files and checks that every affected component has a new version, and a GitHub workflow that monitors errors across the more than 3,000 integrated apps. I also developed new source and action components for the platform.
Result
Missing version bumps are caught in the pull request itself, before publishing, and errors in integrated apps are reported by an automated workflow instead of manual review.
  • Node.js
  • JavaScript
  • TypeScript
  • GitHub Actions
  • REST APIs

Global professional services firm · pharmaceutical sector

Event-driven pharmacovigilance platform

Node.js backend developer

Problem
Pharmacovigilance information came from several sources and had to be centralized, and duplicate records had to be found reliably.
Solution
Within an event-driven microservices architecture on AWS, I implemented GraphQL endpoints and Lambda functions in Node.js and TypeScript on top of PostgreSQL on RDS, plus simple and compound Elasticsearch queries to detect duplicate data.
Result
The information was centralized behind a GraphQL API, with search-based duplicate detection.
  • Node.js
  • TypeScript
  • GraphQL
  • AWS Lambda
  • Elasticsearch
  • PostgreSQL
  • Sequelize
  • Docker

Automotive marketing software company

Serverless backend for video creation

Node.js backend developer

Problem
A video creation app needed to upload videos in different resolutions to an editing engine (OpenShot) and keep the app state in sync.
Solution
I implemented uploading videos in several resolutions to OpenShot with multipart HTTP requests, on a Node.js and AWS Lambda backend, with Firebase and Cloud Functions for the app state.
Result
Video uploads in several resolutions run on a serverless backend, with no servers to maintain.
  • Node.js
  • AWS Lambda
  • Firebase
  • Cloud Functions
  • OpenShot

Global tool manufacturer · United States

Tool inventory backend integrated with Salesforce

Node.js developer · 1 year and 5 months

Problem
Construction companies needed to register, track and customize their tools across multiple job sites, and that inventory had to reach the CRM (Salesforce) and onboard new users easily.
Solution
I implemented the tool registration API for Salesforce and SMS invitations, improved tool import and export, and wrote unit and integration tests, while fixing bugs and supporting production.
Result
Tools registered in the product reach Salesforce through an API, and new users are invited by SMS.
  • Node.js
  • JavaScript
  • REST APIs
  • Salesforce
  • SMS

What I need from you

  • A description of the problem and who will use the system
  • Documentation and test credentials for the systems to integrate
  • Access to the repository and cloud account, or the decision to create them
  • Someone who can make product decisions

Frequently asked questions

Which technologies do you work with?

Node.js and TypeScript with NestJS or Express, GraphQL, PostgreSQL, MongoDB and DynamoDB, and AWS (Lambda, API Gateway, containers).

Can you work on an existing codebase?

Yes. I start by understanding the code and its tests, and propose changes within the architecture you already have.

Who owns the code?

The code is yours and lives in your repository from day one.

Are tests included?

Yes. Every package includes automated tests for the delivered behavior.