API ENGINEERING

API Design and Development

Vivid Concept designs and builds APIs in Los Angeles for your apps, partners and older systems: REST and GraphQL interfaces, webhooks, authentication, versioning and documentation.

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Designing the API around your data and users

An API is the doorway other software uses to reach your data. Our API integration work connects your business to doorways other companies built; API development builds your own, the interface your apps, partners and automations are built around.

Design begins with the people and programs that will call it: the objects they need, the actions they take, the volume they send and the failures they must survive. In specification-first design, the interface is then set out in a machine-readable description before any server code exists.

That specification lets your website, your phone app and your partners' systems be built against the API while the API itself is being built, so the work runs in parallel instead of in sequence.

One API can serve several clients at once: your website, a phone app, a partner feed and dashboards from our internal tool development. Designing it once for all of them costs less than a separate back end for each. It also gives agent-based business automation a safe route in, because an AI agent calls the same checked interface as every other client. AI assistants reach it the same way through our work on connecting AI assistants to your systems.

IN-HOUSE ADVANTAGE

Connected With Our Full Los Angeles Team

Our developers design, document and test your API, so every partner and app connects to it with confidence.

What Is Included in API Development

Your API Development Process

DiscoveryWe review your setup, audience and goals, and you receive a clear scope before work starts.
DesignKey choices are settled with you before work starts.
BuildBuilt by our in-house team with no handoffs.
LaunchEvery change is tested and reviewed by a person before it goes live.
SupportThe team that built it stays available after launch.

REST or GraphQL, chosen per use

Close-up of hands on a laptop beside a printed diagram of connected boxes.

We choose the style by who calls the API. REST suits most business APIs: resources with clear addresses, standard web caching and tools that every developer already knows.

GraphQL pays off when many different screens need different slices of connected data, as in a product with web and phone clients that would otherwise make a dozen requests per view. Many systems use both, with REST for partners and integrations and GraphQL for the product's own interface.

A headless commerce development project is a typical case, and a front end built with Next.js development works with either style. We record the reasons for each choice, so the decision stays clear for years to come.

A backend developer explains a diagram of two connected systems to a partner on a tablet.

Webhooks, queues and retries

Polling an API every minute to ask whether anything changed wastes requests and still arrives late. Webhooks reverse the flow: your system sends a signed message to the subscriber the moment an event occurs, such as a paid invoice or a shipped order.

Delivery is where the engineering lives. Each message is signed so the receiver can verify the sender, deliveries are queued, failures are retried on a schedule that backs off, every attempt is recorded and subscribers can replay anything they missed.

Incoming events get equal care, when a payment or carrier service sends them to you. A paid order or a shipped parcel is still recorded when a connection drops for a moment, because the retry and the replay bring it through.

Authentication, rate limits and versioning

An engineer at a desk with two screens showing abstract queues and retries, calm and focused.

Each kind of client gets the access it needs and no more. Server-to-server partners use keys or OAuth client credentials, and apps acting for a person use OAuth with scopes that name what the person allowed.

Rate limits protect the service from a runaway script, with clear errors that tell the caller when to retry. Versioning protects the clients you cannot update: a breaking change ships as a new version, the old one keeps running for a published period, and callers hear about it before it ends. That versioning also lets a modern interface wrap a legacy database, so new apps start now while replacing aging applications proceeds behind it one part at a time.

Phone apps depend on this most, because an installed app cannot be forced to update. Native clients from iOS app development and Android app development rely on it, and so does mobile app development built on one codebase.

A team reads partner documentation on a laptop together, one pointing at a step.

Documentation, testing and monitoring

Documentation turns an API into something partners can use on their own. Reference documentation is generated from the contract, with worked examples and a sandbox where a partner can test without touching live data.

Automated tests check every endpoint against the contract before each release, so a change that breaks documented behavior is caught before anyone depends on it. In production, each request is traced with an identifier, error rates and response times are watched, and failures raise an alert.

The API sits at the core of our custom software development, and the same documented foundation carries the sites from our web development services and, for products you sell to the public, software-as-a-service builds.

23 Years in Los Angeles

Campus StorageCustom e-commerce infrastructure and management system.

API Development Questions & Answers

REST or GraphQL: which should we use?

REST fits most business APIs and partner integrations. GraphQL fits products whose screens need many connected pieces of data in one request. The recommendation follows a review of who calls the API and what data they need, and some systems use both.

How do you secure an API?

Every request is authenticated, every action is checked against the caller's permissions, traffic is encrypted, inputs are validated and rate limits apply. Every request is traced, and the interface is tested for common attacks before release.

Can you wrap an older system in a modern API?

Yes. A service in front of the old database or application exposes clean, documented endpoints. New apps use the interface, the old system keeps running, and its parts can be replaced one at a time.

How are changes released without breaking partners?

Additions that leave existing callers unaffected ship in the current version. A breaking change ships as a new version, the old one stays available for a published period, and partners hear about it in advance and can test in the sandbox.

Do you write the documentation?

Yes. Reference documentation is generated from the interface contract, with worked examples and a sandbox added, and both are refreshed with every release so they match the real behavior.

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API Design and Development