Systems integration and API development
Systems integration is the connection between different software, such as ERPs, CRMs, payment platforms and in-house applications, so they exchange data automatically, securely and reliably through APIs. Wisalo, a software house based in Curitiba, Brazil, founded in 2019, builds APIs and integrations that eliminate duplicate data entry and connect the business to its digital ecosystem.
Overview
Companies use several systems at once, and each one holds part of the truth. Without integration, someone has to copy data from one to another, with delays and risk of errors. A well-built integration handles that exchange on its own and raises an alert when something goes wrong.
We build integrations with failure in mind: third-party systems go down, respond slowly or change without notice. That is why we use timeouts, controlled retries, queues, idempotency and monitoring, so an external problem doesn't bring down your operation or duplicate records.
Every integration is documented: which data flows, in what format, how often and who owns each piece of information. Contracts are versioned and automatically tested, so changes on one side don't silently break the other. Partner credentials are kept in secret vaults with the least access required, and logs record enough to diagnose problems without exposing personal data or financial information.
Who it is for
Companies with systems that don't talk to each other
Businesses that enter the same data into multiple systems and struggle with inconsistent information.
Products that need a public API
Platforms that want to let customers and partners integrate with them in a secure, documented way.
E-commerce and payment operations
Businesses that need to connect their store, payment methods, tax invoicing, inventory and logistics.
Companies with fragile integrations
Organizations whose current integrations fail frequently, with no alerts and no easy way to reprocess.
Problems we solve
Duplicate data entry and inconsistent data
We synchronize records, orders and statuses across systems, with a defined source of truth for each piece of information.
Integrations that fail silently
We add monitoring, alerts and reprocessing queues so no failure goes unnoticed.
Duplicate payments and webhooks
We apply idempotency and signature verification to process each event exactly once and securely.
APIs without documentation or versioning
We create versioned contracts with OpenAPI, so consumers can evolve without breaking.
Dependence on a legacy system
We isolate the legacy system behind an integration layer, allowing gradual modernization.
What we deliver
REST and GraphQL APIs
Versioned, authenticated and documented APIs, with standardized error handling and usage limits.
ERP integration
Connection with ERPs such as SAP and TOTVS to synchronize records, orders, inventory and financial information.
Payment gateways
Integration with payment methods, including webhook confirmation and reconciliation.
CRM integrations
Synchronization of leads, contacts and opportunities between website, internal systems and CRM.
Third-party APIs
Consumption of external services, such as logistics, messaging, maps and government services, with a protection layer.
Microservices and messaging
Asynchronous communication with queues to absorb spikes and isolate failures, when the architecture calls for it.
Technologies and stack
We use open integration standards and established messaging and security tools:
- REST
- GraphQL
- gRPC
- Webhooks
- OAuth 2.0
- OpenAPI
- RabbitMQ
- Node.js
- Java
- Python
How we work
Mapping
We identify the systems, the data exchanged, volumes, frequency and the source of truth for each piece of information.
Contract design
We define the API or integration contract, data formats and error handling.
Development and testing
We implement with contract and integration tests in partners' staging environments.
Monitored release
We release with logs, metrics and alerts, closely tracking the first real volumes.
Maintenance
We track changes in partners' APIs and evolve contracts without breaking consumers.
Frequently asked questions
Do you integrate with SAP and TOTVS?
Yes. Wisalo builds integrations with ERPs such as SAP and TOTVS using the interfaces each environment provides, such as APIs, web services or file exchange, depending on the client's setup.
What is the difference between REST and GraphQL?
REST organizes the API into resources with fixed endpoints and is the most widely adopted standard. GraphQL lets the consumer request exactly the fields it needs in a single query. We recommend REST as the default and GraphQL when there are many consumers with different needs.
How do you avoid duplicate payments or orders in integrations?
With idempotency: each operation receives a unique identifier, and the system recognizes repeats and does not process them twice. We also verify the signature of incoming webhooks.
What happens when the partner's system goes down?
The integration uses timeouts, retries with increasing intervals and queues. Messages that cannot be processed are stored for reprocessing, and the team is alerted.
Do you document the APIs?
Yes. Every API is documented with OpenAPI, versioned in the path (for example, /v1) and evolved in a backward-compatible way, so consumers are not caught off guard.
Do you maintain the integrations after they are delivered?
Yes. We monitor alerts, volumes and changes in partners' APIs and make the necessary adjustments, so the integration keeps working as the systems involved evolve.
Shall we talk about your project?
Tell us the context, goals and constraints of your challenge. A Wisalo specialist will get back to you with the next steps.
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