Rafael Nunes— Software development
PT Contact me
Service

REST APIs and system integration

Your systems, partners and suppliers exchanging data automatically, with no manual typing.

Tell me your project Chat on WhatsApp

What is a system integration?

A system integration is an automatic bridge that lets two or more software products exchange information — via REST APIs, webhooks, files or standards such as EDI. Instead of someone copying data from one screen to another, the system itself sends, receives, validates and logs every exchange.

Who it is for

  • Companies typing the same data into more than one system
  • Logistics operations exchanging files with customers and carriers
  • Products that need to expose an API to partners
  • Teams with legacy systems that must talk to new services

Problems it solves

  • Data mismatches between systems and manual reconciliation at the end of the day
  • Typing errors that become losses or rework
  • Partners asking for an API you do not have
  • Fragile integrations that break without anyone noticing

What can be built

  • ASP.NET Core REST APIs with Swagger documentation
  • Webhooks and queues to process events safely
  • EDI and file exchange with customers and carriers
  • Token authentication, API keys and rate limits
  • Logs for every exchange, reprocessing and failure alerts
  • Integration with SQL Server and legacy systems

How it works

  1. 1

    Mapping. I map which systems exchange which data, how often and in what format.

  2. 2

    Integration contract. I define endpoints, fields, validations and what happens when something fails.

  3. 3

    Development and tests. I build the API or connector with automated tests and a staging environment.

  4. 4

    Validation with real data. We run it alongside the current process until reconciliation matches.

  5. 5

    Monitoring. Logs, alerts and documentation so the integration never becomes a black box.

What you get

  • API or connector in production
  • Swagger/OpenAPI documentation
  • Automated tests
  • Logs and reprocessing routine
  • Usage guide for partners
  • Source code owned by your company
  • ASP.NET Core
  • C#
  • REST
  • Webhooks
  • EDI
  • SQL Server
  • Swagger

How much does it cost?

The price depends on scope: number of screens and business rules, integrations and deadline. After the kick-off call you get a written proposal stating what is included and what is not — no surprises halfway through.

How long does it take?

A single integration between two systems usually takes a few weeks. Full APIs or EDI integrations with several partners are delivered in stages, starting with the highest-volume flow.

Related projects

Frequently asked questions

Can you integrate with a system that has no API?

Often yes: through the database, file exchange or automation. I review what the system offers and pick the most stable path.

What is EDI?

EDI (electronic data interchange) is a standard for companies to exchange documents such as orders, invoices and delivery status automatically. I have built an EDI platform for UPS.

What if the integration fails at night?

Every exchange is logged, failures trigger alerts and can be reprocessed without losing data.

Will you document the API for my partners?

Yes. I deliver OpenAPI/Swagger documentation and a usage guide with examples.

Read before deciding (in Portuguese)

Let’s talk

Shall we talk about apis and integrations?

Tell me what you need. If custom software is not the best path, I will say so — and point you to what makes sense.

  1. 1You describe the project in 2 minutes.
  2. 2I reply within a few hours and we schedule a call.
  3. 3You get an honest assessment and, if it makes sense, a proposal with scope, timeline and price.

Prefer another channel?

Chat on WhatsAppFastest replyEmaildevrafaelnunes@gmail.com
Step 1 of 3 · Your project33%
What do you need?

In your own words: what happens today, what goes wrong and what the ideal would be.

Reply within a few hours. No spam, no commitment.