Fintech & SaaS Engineering

# Build the workflow across your services.

Deliver a product feature that spans an API, payment system, database and background jobs. Upserto defines the state changes and failure handling with your team, then implements and tests the agreed delivery milestone.

[← All services](/services)

## Keep the change and the intent together.

Commit the business change and the outbox record in one transaction. A separate relay may redeliver; the consumer protects its local effect from duplicates.

## Example scope & report

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

[Read Polar billing to product access: example scope ↗](/examples/fintech-delivery)Public-product reference · proposed delivery plan.

## When this is useful

Fintech and SaaS teams that need a feature delivered across several existing components.

- A feature crosses several services, but no one owns the complete delivery.

- A retry or delayed event leaves the customer seeing the wrong state.

- Each integration passes its own checks, but the complete customer journey still fails.

## How the work happens

- Define one product milestoneMap the users, permissions, states and external dependencies. Agree the first useful release and the checks that establish completion.

- Implement the connected changesUpdate the required APIs, workers and integrations. Identify which component owns each record and transition, including retries and recovery.

- Test the complete journeyFollow the workflow across components, including failures and restarts. Report local, shared-environment and production checks separately so release decisions use the right evidence.

## What your team receives

- A delivery plan with reviewable changes at agreed milestones.

- Tests for the changed business rules and service interactions.

- Release and recovery instructions, dependencies and remaining checks.

## Can Upserto work with an existing engineering team?

Yes. Work happens in the agreed repositories and review process. Your team agrees access, responsibilities and acceptance for each milestone.

Start with a clear scope

Milestones quoted after scoping

[Book a free 30-minute discovery call ↗](/contact)The proposal sets the scope, milestones and availability. Compliance certification, regulated product decisions and 24/7 support are separate responsibilities.

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

## Related engineering services

[Backend & API Development ↗](/services/backend-api-development)[Payment Infrastructure & PSP Integrations ↗](/services/payment-psp-integrations)[Technical Architecture & Code Audits ↗](/services/technical-architecture-code-audits)[Technical Consultation & Advisory ↗](/services/it-consulting)[AI Integration & Automation ↗](/services/ai-integration-automation)[Cybersecurity Review & Vulnerability Research ↗](/services/cybersecurity-review)[Expert Code & Architecture Review ↗](/services/code-architecture-review)

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