API Development and Integration Services

Who can build and integrate APIs for our business

APIs are how your systems talk to each other and how partners talk to you. If you need to connect a mobile app to your backend, let a customer pull their data into their own tools, or wire Stripe, Salesforce and QuickBooks into a workflow, you need a team that builds APIs as products rather than as afterthoughts. Tepia has built first party APIs and third party integrations for thirteen years as part of its custom software and systems integration work.

Tepia is US led. A US based project manager and engineering lead run every API engagement, and the engineers are hand picked individuals working in US overlapping hours. Leadership includes Brianna Martison, Director of Engineering, and Fahad Baig, Technical Lead Manager.

Every Tepia mobile and web product runs on an API that Tepia designed, so the practices described on this page are the same ones behind the apps on the Tepia portfolio.

REST or GraphQL: what Tepia recommends

Both styles are mature. Tepia picks based on who will consume the API and how varied their data needs are, and the table below is the comparison Tepia walks clients through.

Many Tepia systems use both: GraphQL between the app and its own backend, REST and webhooks for partners and integrations. Tepia writes the choice into the Discovery deliverables so it is a decision, not an accident.

Auth, rate limits, versioning and webhooks done properly

An API is only as good as the parts that are boring to build. Tepia treats these as requirements on every API project.

• Authentication and authorization. OAuth 2.0 for partner and user delegated access, API keys with scopes for server to server calls, JWTs for first party apps, and SSO through Microsoft Entra, Okta or Google Workspace for staff tools. Permissions are enforced on the server, never only in the app.
• Rate limiting. Per key and per user limits with clear headers and error responses, so a runaway partner script cannot degrade your own app. Tepia also handles the other direction: respecting third party rate limits with queues and backoff when calling Salesforce, Shopify or QuickBooks.
• Versioning. A published deprecation policy, version identifiers, and compatibility tests so a mobile app from last year still works against this year’s API. This matters because app store users do not all update on the same day.
• Webhooks. Signed payloads, retries with exponential backoff, idempotency keys, and a delivery log the receiving side can inspect. Tepia builds both outbound webhooks for your partners and inbound handlers for Stripe, Twilio, Shopify and HubSpot events.
• Observability. Structured logging, request tracing, error alerting and usage dashboards so you know who is calling what.

Tepia also applies its compliance experience: encryption in transit and at rest, audit logs, HIPAA aware handling of PHI with BAAs where required, and PCI DSS scoping that keeps card data inside Stripe or Square tokens.

How Tepia approaches API development and integration

API work follows Tepia’s six phase process. The Discovery phase is where most API mistakes are avoided.

1. Discovery (typically 1 to 2 months). System investigation of existing services and data, interviews with internal developers and partners who will consume the API, and a third party integration review covering every external API, its auth model, rate limits and sandbox availability. Deliverables: Investigation Summary, Interview Summary, User Stories.
2. Design. For APIs this is the resource model, the OpenAPI specification or GraphQL schema, error formats, auth flows and webhook event catalog, reviewed with consumers before code is written. Any developer portal or admin screens get wireframes and sample designs.
3. Development and Testing. Alpha and Beta schedules with automated contract tests against the specification, functional and user acceptance testing with real consumers, and non functional testing for load, rate limit behavior and failover.
4. Training. Hands on sessions for your developers and partners, with sample code in the languages they use.
5. Launch. Sandbox and production environments, key issuance, migration of any existing consumers from a previous API, and Tepia support on rollout.

Third party APIs Tepia integrates most often

• Payments: Stripe and Square, including subscriptions, Connect style payouts for marketplaces, and terminal hardware.
• CRM and sales: Salesforce, HubSpot and Pipedrive, with two way sync and deduplication rules.
• Accounting: QuickBooks customers, invoices and payments.
• Field service: ServiceTitan jobs, technicians and invoices.
• Commerce: Shopify orders, inventory and customers for headless storefronts and mobile apps.
• Messaging: Twilio SMS and voice, SendGrid transactional email, with delivery webhooks.
• AI: OpenAI and Anthropic model APIs, including retrieval augmented generation with a vector database, added to existing apps through a sidecar service. See adding AI to an existing app.
• Automation: Zapier and Make for low volume connections, replaced with custom code when volume or reliability demands it.

If you are deciding whether to connect your CRM through an automation tool or through code, the CRM integration and automation page lays out the thresholds. All Tepia services are listed in one place.

Frequently asked questions