API Development &
Integration.
We design versioned APIs, build secure system-to-system integrations, and implement monitoring layers that detect the moment data falls out of sync.
The cost of disconnected systems.
Data silos, manual re-entry, and brittle integrations create operational drag that compounds with every new tool your team adopts.
Data silos between platforms
Customer data lives in your CRM, financial data in your ERP, orders in your e-commerce platform. No single source of truth exists, and teams spend hours reconciling conflicting records.
Manual data re-entry across tools
Staff copy-paste records from one system to another. Each manual transfer introduces latency, formatting mismatches, and the risk of transposition errors that cascade downstream.
Brittle point-to-point integrations
Direct connections between systems break when either side changes a field name, adds a required parameter, or updates an authentication method. Each fix is reactive and expensive.
No visibility when systems fall out of sync
When a webhook fails or a sync job silently drops records, nobody knows until a customer complains or a report shows incorrect numbers. There is no alerting layer in place.
Enterprise-grade APIs. Built to last.
Every API we build follows five core principles: documented contracts, semantic versioning, security by default, full observability, and resilient error handling.
Custom REST APIs
Documented, versioned APIs designed around your domain. Clean endpoint structures, consistent error handling, and OpenAPI specs generated automatically.
Webhook infrastructure
Event-driven notifications with retry logic, signature verification, and delivery tracking. Your systems react to changes in real time instead of polling.
Real-time data sync
Bidirectional synchronization between your CRM, ERP, and operational platforms. Conflict resolution rules handle concurrent updates gracefully.
Authentication & authorization
OAuth 2.0 flows, JWT validation, API key management, and role-based access control. Every endpoint protected by default.
API gateway management
Rate limiting, request routing, load balancing, and caching layers. A single entry point that manages traffic across all your microservices.
Integration testing & monitoring
Automated contract tests, load tests, and synthetic monitoring. Catch breaking changes before they reach production.
From API design to production reliably.
Every integration follows the same structured process. Documented contracts first, then iterative development with automated testing at every step.
API design & documentation
We map your integration requirements, define endpoint contracts, and produce OpenAPI specifications. Every payload, error response, and authentication flow is documented before development begins.
Development & testing
Iterative API development with automated contract testing at every step. Endpoints are built, validated against specifications, and load-tested with production-scale traffic patterns.
Integration & security
Connect your systems through the API layer. Authentication flows, rate limiting, and monitoring are configured. End-to-end integration tests verify data flows correctly across every platform.
Deploy & monitor
Staged deployment with monitoring dashboards, alerting rules, and runbooks. Your team has full visibility into every request, error, and performance metric from day one.
Connects to the platforms your business runs on.
We build APIs and integrations for the tools your team already uses. No migration required.
And 200+ more platforms via custom REST and GraphQL connectors.
Our systems were held together with manual CSV imports and prayer. Necsen designed a proper API layer that connected our CRM, billing, and warehouse systems. Data flows in real time now, and we haven’t had a sync failure in six months.
Common questions.
How do you decide between REST and GraphQL?
REST is our default for simplicity, cacheability, and broad tooling support. We recommend GraphQL when reducing over-fetching significantly improves mobile performance or when your frontend team needs flexible query capabilities across complex data relationships.
How do you handle API documentation?
Every API ships with an OpenAPI 3.0 specification generated directly from the codebase. This drives auto-generated documentation portals, client SDK generation, and contract test suites that validate the API matches its specification.
What rate limiting strategies do you implement?
Tiered rate limiting: token bucket for general access, sliding window for authentication endpoints, and fixed window with burst allowance for webhooks. Limits are configurable per client and monitored in real time.
How do you ensure API security?
Every API follows the OWASP API Security Top 10. Authentication uses OAuth 2.0 with PKCE for public clients, API keys with HMAC signing for server-to-server, and mTLS for environments with strict regulatory requirements.
What is your API versioning strategy?
URL-based semantic versioning (v1, v2) for major breaking changes, header-based versioning for minor additions. We maintain a six-month deprecation window with migration guides and automated consumer notifications.
What monitoring and alerting is included?
Dashboards showing request volume, latency percentiles (p50/p95/p99), error rates, and upstream health. Alerts trigger on latency spikes, error threshold breaches, and certificate expiration. All included with every deployment.
Ready to connect your systems?
Tell us about your integration challenges. We review your integration landscape and provide a fixed-scope proposal within 48 hours.
No commitment. No pitch deck. Just a technical conversation.