Backend & API Development

# Build the API. Fix the job. Ship the change.

Add an API, connect a service or fix a backend problem in your existing Go or PHP/Laravel application. The work includes the code, tests for the affected paths and the steps your team needs to release it.

[← All services](/services)

## A request is only the beginning.

Accepted work enters a durable queue. Independent tasks join only after their outputs are ready; a failed task has a bounded retry path.

## Example scope & report

See the project brief, proposed solution and acceptance checks for work around a public product.

[Read Medusa supplier import: example scope ↗](/examples/backend-delivery)Public-product reference · proposed delivery plan.

## When this is useful

Product and engineering teams with an existing backend and a specific feature, failure or performance problem to resolve.

- An endpoint returns inconsistent errors or exposes data to the wrong user.

- Database queries are slow, a queue stops progressing or an external call leaves work unfinished.

- A feature needs coordinated changes to the API, database and background jobs.

## How the work happens

- Follow the request or jobRead the relevant handlers, database queries and service calls. Reproduce the problem where access allows, then agree the expected behaviour and the changes in scope.

- Change the existing codeImplement validation, permissions, data updates and failure handling in your repository. Keep changes small enough for your team to review and flag any migration or interface change.

- Test and prepare the releaseTest normal requests, failures and retries. For performance work, compare the same workload before and after the change. Include configuration, migration and rollback steps where needed.

## What your team receives

- A pull or merge request in your repository.

- Tests for the changed behaviour, with results and any checks still outstanding.

- API or migration notes, configuration changes and release instructions.

## Can Upserto improve an existing backend without rewriting it?

Yes. The first proposal focuses on the smallest change that solves the agreed problem. A wider refactor needs a separate reason, scope and estimate.

Start with a clear scope

Small scoped tasks from $1,000

[Book a free 30-minute discovery call ↗](/contact)Starting work covers one agreed task. Large migrations, infrastructure changes, on-call coverage and ongoing maintenance are quoted separately.

Confidentiality, access, milestones and acceptance criteria are agreed before work starts. Please leave secrets out of your first enquiry.

## Related engineering services

[Payment Infrastructure & PSP Integrations ↗](/services/payment-psp-integrations)[Technical Architecture & Code Audits ↗](/services/technical-architecture-code-audits)[Fintech & SaaS Engineering ↗](/services/fintech-saas-engineering)[IT Consulting ↗](/services/it-consulting)[AI Integration & Automation ↗](/services/ai-integration-automation)[Cybersecurity Review & Vulnerability Research ↗](/services/cybersecurity-review)

Contact: [hello@upserto.com](mailto:hello@upserto.com)