API contracts before integration work
We define endpoints, payloads, validation, errors and responsibilities before services start depending on them in production.
Connected systems, clear APIs
API Development & Integration
API architecture for web apps, dashboards, integrations, data sync and external services.
APIs, webhooks, sync, support
Integration architecture first
We plan API contracts, data flow, auth, webhooks and errors before integrations become hard to support.
- REST API and GraphQL planning flow
- Third-party service integrations
- Webhooks and data sync workflows
- Auth, tokens and access rules setup
- API docs, testing and support plan
API layers that make product data usable
API Development & Integration Services help teams connect products, services and data without relying on fragile scripts or unclear manual work.
Kavita Systems does not treat API work as simply adding endpoints or connecting a vendor. We first review the business process, systems involved, data ownership, access rules, error cases, rate limits, retries, logs, security needs and support expectations.
We can join at different stages. New products may need a first API, MVP backend, platform layer or integration flow. Scaling products may need more consumers, more services, larger data movement or stronger contracts. Support work can focus on unstable integrations, missing logs, failed jobs, webhook errors or sync problems.
Modernization can repair old endpoints, manual exports, legacy APIs and older PHP, Laravel, WordPress or Yii systems. A full rebuild is not always needed. Sometimes the safer path is to document the flow, stabilize the risky connection, add logs and move the most important data exchange into a better backend layer.
Architecture is selected for the product: API-first, headless backend, decoupled frontend, modular Laravel monolith, Inertia.js monolith or AI-oriented option. We use Laravel, PHP, REST, GraphQL, MySQL, PostgreSQL, Redis, queues, Docker, cloud tools, Nuxt, Next, Vue, React, Node.js and AI providers only when they fit the integration problem.
You get more than endpoints: a supportable integration layer with clear contracts, data flow, access control, logs, retries, documentation and room for future systems.
API scope and system review plan
We review systems, tools, data owners, business goals and manual work so the first integration solves the right problem for users.Data flow and contract planning
API contracts, field mapping, source-of-truth rules and response formats are planned before teams and connected services depend on them.Auth and access model setup plan
Tokens, OAuth, roles, partner access and permissions are designed before sensitive data reaches production systems or external partners.Integration build and testing flow
Third-party services, payloads, errors, rate limits and edge cases are tested before users and staff rely on the connection in production.Webhooks, queues and retry logic
Event handling, background jobs, retries, duplicate protection and logs help long operations run without blocking users or staff work.Launch, logs and support path plan
Before release we check critical flows, monitoring, failed jobs and support notes, then plan the next improvement after launch review.Kavita Systems treats API work as a product layer, not a set of random endpoints. We clarify data flow, users, systems, security, risks, architecture and budget, then connect backend, frontend, external services, AI features, QA and support through visible milestones.
Practical
Product Engineering
From Plan to Launch
Data flow mapped before coding starts
Source systems, fields, statuses, IDs and sync direction are reviewed before data moves automatically between connected services.
Secure access for every connected system
Tokens, roles, partner access and sensitive actions are checked by the backend, not only by the UI, across connected tools.
Webhooks and retry logic planned early
Duplicate events, failed calls, retries, logs and recovery paths are planned before live operations and teams rely on them.
Laravel backend for stable API logic
Laravel keeps business rules, provider adapters, jobs, logs and access checks in one backend layer that support can review.
Support after integrations are live
After launch, we help track errors, update providers, review logs and improve the next integration step with product history.
Integration Process
Contracts, data, reliability
API development and integration work succeeds when the connection protects the business process behind it. The important question is not only whether two systems can exchange data. It is who owns each record, what users expect to happen, how failures are noticed, which actions are allowed and what support needs when something arrives late, twice or not at all.
We start with the workflow that the API must serve. A customer portal may need account data, orders, files and notifications. A SaaS dashboard may need search, filters, exports and usage limits. A marketplace, booking platform, payment flow or AI-assisted product may need provider callbacks, background jobs and review states. REST, GraphQL, webhooks, sync jobs or backend-for-frontend patterns are selected after those needs are clear.
A contract is the first serious deliverable. We define request and response shapes, required fields, validation rules, status meanings, authentication, rate limits, error formats, versioning expectations, webhook events and documentation gaps. This contract gives frontend, backend, external providers and future maintainers the same reference point. It also helps clients understand what a failure means instead of treating every integration issue as a mystery.
Versioning and documentation are part of reliability. Internal endpoints, partner APIs and public integrations need enough notes for another developer to continue the work later. We document payloads, permissions, status codes, retry behavior, webhooks, known limits and support actions. The documentation does not need to become a large manual, but it should explain decisions that affect releases, mobile clients, partner teams or future automation.
Data ownership must be decided before automation starts. We map which system creates each record, which fields can be updated, which values are read-only, how IDs are matched and how conflicts are handled. This matters for CRMs, ERPs, payment processors, booking systems, supplier feeds, analytics, internal dashboards and AI pipelines. Without a clear ownership model, integrations create duplicates, broken reports and support work that could have been avoided.
Laravel keeps integration logic in a controlled backend layer. Routes, resources, policies, form requests, service classes, queues, events, scheduled commands, logs and notifications can live in predictable places. A modular monolith may be enough for internal products. API-first or headless architecture can fit mobile clients, partner access or separated frontends. Decoupled setups make sense when React, Vue, Nuxt or Next screens need independent deployment while Laravel owns rules and data changes.
Webhooks and background work need recovery paths. External systems may send events out of order, send duplicates, fail validation, hit rate limits or change payloads. We plan idempotency, retries, failed-job review, manual repair, logging and alerting before launch. Redis can support queues and locks; MySQL or PostgreSQL can store transactional state; BigQuery is useful when analytics volume justifies it. The product should make failures visible and recoverable for the team supporting it.
Interface design still matters for API-heavy products. Users need to see loading, queued, failed, outdated, synced, pending review or partially connected states. Figma helps design those states before the contract is final. Figma Agents can explore dashboard, admin and data-table directions. Figma MCP can bring approved design context closer to Vue, React, Nuxt, Next or Inertia implementation, but it does not remove the need for engineering judgment around permissions and backend behavior.
AI can assist integration work, but it should not own security decisions. Some products only need an AI-ready structure with clean data, queues and service boundaries. Others may use OpenAI, Claude, Gemini or Laravel AI SDK to summarize records, classify incoming messages, draft support replies or search internal knowledge. AI coding agents can compare provider docs, draft adapters or suggest tests, while senior developers still decide credentials, scoped access, recovery rules and architecture fit.
QA for integrations is built around failure, not only a happy request. We test missing fields, expired tokens, duplicate webhooks, slow providers, bad permissions, rate limits, rollback needs, empty responses, malformed payloads and unclear errors. AI-assisted tests can help generate variations, but real confidence comes from checking the business outcome: what the user sees, what the backend stores, what gets logged and how support can respond.
Launch includes observability and support notes. Before release, we prepare environments, keys, queue workers, monitoring, failed-job review, documentation and rollback awareness. After launch, provider behavior may change, more endpoints may be needed or the first contract may need versioning. Kavita Systems stays practical: we track work, explain tradeoffs, show demos and help the client understand how connected systems behave after real users depend on them.
Technology stack
chosen for delivery
Practical tools for real releases. A focused mix of design, app frameworks, data tools, automation, hosting, and quality checks selected around each product.
Technical
Expertise
API Strategy Plan
Choose REST, GraphQL, headless, API-first or backend-for-frontend patterns around product goals and support needs early.
Laravel API Core
Build Laravel routes, resources, validation, service layers, policies, queues and backend logic for connected products and teams.
Webhook Flow Map
Handle signed events, duplicate payloads, retries, queued work, failed calls and support logs for event-based flows after launch.
Data Sync Rules
Plan field mapping, source-of-truth rules, storage, reports, statuses, IDs and audit trails before records move between tools.
Auth Token Rules
Design user auth, API tokens, OAuth, service credentials, roles and partner access for integrations across systems and teams.
Integration Build
Connect CRMs, ERPs, payment tools, booking systems, emails, analytics, external APIs and internal services with logs and checks.
AI Endpoint Layer
Route AI search, summaries, document analysis and automation through backend permissions, logs, queues and usage limits.
Launch Support Plan
Prepare QA, deployment, monitoring, failed-job review, API usage checks and support notes after integrations launch work.
Selected Product Work
Some work is public, while many long-term client systems remain private under NDA.
Hotel Booking Platform
Years active: 2015 — 2025
Hotel booking service for searching destinations, comparing deals, reserving rooms and managing trip details across a large global catalog.
Key points: 100,000+ hotels, 200+ countries, 2,000+ cities, multilingual content, SEO pages, trip lookup, group booking and support workflows.
Skills & Deliverables:
How
to start
working with us?
Project CallWe define goals, risks, budget, timeline, and a useful first scope.
Upwork TermsWe set Upwork terms, milestones, rates, and contact rhythm clearly.
Tracked WorkYou see hours, updates, blockers, demos, and decisions in one spot.
Release CareWe ship the agreed result, fix release issues, and plan next steps.
Frequently Asked Questions
Yes. You do not need to know the full API structure before we start. We can begin with the basics: which tools you use, what data needs to move between them, who should access it, and what should happen when something fails. After that, we turn the integration into a clear technical plan instead of guessing during development. This makes scope, risks, and first milestones much easier to understand.
We can do both. Sometimes the product needs a new API layer for a web app, dashboard, mobile app, or partner system. Other times, the work is about connecting to an existing API, cleaning up old endpoints, replacing manual exports, or making a fragile integration more reliable. The right approach depends on the current system, business rules, data ownership, and how the API will be used after launch.
Yes. Not every old system needs to be rebuilt from scratch. We can review the current API, database, sync logic, logs, failures, and business rules. Then we decide what is safer: fix the existing flow, wrap it with a better API layer, rebuild selected parts, or plan a gradual modernization. The goal is to protect working business logic while reducing risk and making the integration easier to support.
We choose based on the product, not based on trend. REST is often a clean and practical choice for dashboards, admin tools, mobile apps, external integrations, and clear resource-based APIs. GraphQL can make sense when the frontend needs flexible data queries or several clients need different data shapes. The main goal is simple: the API should be understandable, stable, and easy to support after launch.
First, we map the data before we move it. We look at where each field comes from, which system is the source of truth, how records match, what statuses mean, what can be updated, and what should stay read-only. This helps avoid duplicate records, broken reports, unclear ownership, and confusing sync behavior later. A good data flow plan makes the integration easier to test, debug, monitor, and support.
We plan access rules early, especially when several users, teams, vendors, or partner systems are involved. That can include user login, API tokens, OAuth, service accounts, role-based permissions, partner access, and limits for sensitive actions. The important part is that security is checked on the backend, not only hidden in the interface. Access rules need to be clear before the API becomes part of daily work.
Yes. Webhooks are useful when one system needs to notify another system about events in real time. We can handle incoming events, verify signatures, process payloads, avoid duplicate actions, queue heavier work, log failures, and make sure the product knows what happened if the webhook arrives late or fails. This helps the integration stay predictable even when the provider sends events in an imperfect order.
We plan for that instead of treating it as a surprise. Depending on the workflow, we may add retries, queues, fallback states, error messages, failed-job logs, alerts, or manual recovery options. A good integration should not break the whole product just because one provider has a bad moment. Users and support teams should understand what happened, what is delayed, and what can be retried safely next.
Yes. Many integrations should not run directly inside a user browser request. Imports, exports, large syncs, file processing, webhook handling, email sending, report generation, and provider calls often work better as background jobs. This keeps the product faster for users and gives the support team a clearer way to track what happened, retry failed work, and understand which records were updated.
Yes. An API is often the layer that connects the backend to the product interface. We can build APIs for Vue, Nuxt, React, Next.js, mobile apps, admin panels, dashboards, partner portals, and internal tools. The API needs to return data in a way that matches the real screens and user actions, not just the database tables. This keeps the frontend easier to build, test, support, and improve later safely.
Yes. We can connect products with third-party services such as CRMs, ERPs, payment systems, booking tools, marketplaces, email platforms, analytics tools, logistics services, and internal databases. Before building, we check what the provider allows, how the API is documented, what limits exist, which events matter, and how the integration should be supported after it goes live and starts handling real data.
Yes, when the API will be used by developers, partners, frontend teams, or future maintainers. Documentation can include endpoints, request examples, response formats, authentication rules, error codes, webhook behavior, field meanings, and important business rules. Good documentation saves time later, especially when the product grows, another team joins, or the integration needs to be changed safely.
After launch, integrations usually need monitoring and small adjustments. Providers update APIs, tokens expire, payloads change, edge cases appear, and users find new ways to use the product. We can help review logs, fix failed jobs, improve sync behavior, add missing fields, update provider logic, and plan the next integration step. The goal is to keep the connection reliable after real use begins.
$25–65
Hourly Rate
Senior talent by role.
1-5
Specialists
Matched to your project.
70,410+
Tracked Hours
Verified Upwork history.
$2M+
Earned on Upwork
Trusted since 2015.