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CUSTOM API INTEGRATION SERVICES

Custom API Integration & Gateway Engineering

We build secure, low-latency API integration ecosystems that connect distributed cloud services, legacy databases, and mission-critical enterprise platforms. By leveraging standardized OpenAPI 3.0 specs, GraphQL federations, and zero-trust mTLS security, our backend architects ensure your business workflows communicate seamlessly with sub-millisecond reliability.

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✓Dedicated Senior Pods
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✓100% US Timezone Overlap
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✓SOC 2 Type II Protected
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✓Agile Rapid Delivery
ENTERPRISE GRADE
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99.999% High Availability
Zero-Downtime Migration Ready
CORE ARCHITECTURE

Enterprise API Architecture & Microservices Gateway Integration

Connecting fragmented software systems requires high-throughput, secure API integration layers. We design modern RESTful and GraphQL API architectures equipped with centralized API gateways (Kong, AWS API Gateway, Apigee) that handle traffic routing, rate limiting, and automated OAuth2 token authentication.

Our integration architectures feature automated OpenAPI/Swagger documentation, schema validation, and edge caching, enabling third-party partners and internal engineering teams to interface effortlessly with your backend services with sub-25ms response latencies.

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REAL-TIME STREAMING

Event-Driven Webhooks & Streaming Asynchronous Sync

Batch synchronization and polling introduce latency, strain databases, and cause data stale-state errors. We engineer real-time event-driven integration fabrics utilizing Apache Kafka, RabbitMQ, and secure webhook distribution pipelines that stream state changes instantaneously.

Equipped with exponential backoff retries, dead-letter queues (DLQ), and idempotent message deduplication, our streaming middleware guarantees that zero transactions are lost during third-party outages or network interruptions across distributed systems.

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SUB-15ms LATENCY
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Real-Time Streaming Engine
Zero-Message-Loss Architecture
SOC 2 & PCI-DSS READY
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Zero-Trust NIST 800-207
AES-256 & mTLS Segregation
AI & MACHINE LEARNING

Legacy Mainframe & ERP System Integration Adapters

Bridging modern cloud applications with legacy on-premise ERPs (SAP S/4HANA, Oracle NetSuite, Microsoft Dynamics 365) requires specialized protocol translation. We build custom middleware adapters that translate legacy SOAP/XML and EDI data formats into lightweight JSON payloads.

Our middleware preserves transaction atomicity and regulatory compliance, allowing enterprise organizations to modernize customer-facing digital portals without undergoing high-risk, expensive legacy core replacements.

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< 25ms
P99 Gateway Latency

Sub-millisecond API proxying, distributed edge caching, and optimized database connection pooling.

99.999%
Enterprise High Availability

Zero single point of failure with active-active multi-region failover and automated circuit breaking.

Zero-Trust
End-to-End Security

Hardened with OAuth 2.0 / mTLS mutual authentication, granular role-based access, and token rate limiting.

100M+
Monthly Payloads Handled

Scalable distributed event streaming and webhook queues that process heavy enterprise volume without drop-off.

Deep Dive: Enterprise API Integration & Middleware Engineering

Discover the integration middleware and API gateway architectures that unify enterprise software ecosystems into synchronized digital backbones.

Kong/Apigee Gateways, Dynamic Edge Caching & FAPI Profiles

Develop resilient API gateway infrastructures capable of handling millions of daily API transactions with sub-25ms p99 latency. Featuring Kong, Apigee, or AWS API Gateway, our architectures implement rate limiting, dynamic edge caching, and Financial-grade API (FAPI) security profiles that protect internal microservices from DDoS and unauthorized access.
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CLOUD-NATIVE
Kong/Apigee Gateways, Dynamic Edge Caching & FAPI Profiles
Enterprise Architecture
Multi-Region Active-Active
API Protocols & Middleware

Enterprise API Architecture & Integration Stack

We engineer robust, standardized integration layers bridging modern microservices, legacy on-prem systems, and leading third-party enterprise platforms.

Protocols, Specs & Runtimes

Standardized API contracts, high-speed binary protocols, and real-time event streaming.

RESTful APIsOpenAPI 3.0 / SwaggerGraphQL & Apollo FederationgRPC & Protocol BuffersWebSockets & SSEWebhooks (HMAC Verified)JSON:API & HALApache Kafka

API Gateways & Management

Centralized traffic governance, rate limiting, SSL termination, and real-time observability.

Kong Enterprise GatewayGoogle Cloud ApigeeAWS API GatewayEnvoy Proxy & IstioTraefik MeshTyk GatewayRedis Rate LimiterCloudflare API Shield

Identity & Zero-Trust Security

Enterprise identity federation, encrypted mutual TLS, and role-based token governance.

OAuth 2.0 (PKCE / Client Credentials)OpenID Connect (OIDC)Mutual TLS (mTLS)JWT & JWE Token EncryptionAuth0 / Okta FederationAWS CognitoHashiCorp VaultSAML 2.0

Enterprise Ecosystem Connectors

Seamless bidirectional data synchronization across core business platforms and databases.

Salesforce CRMSAP & NetSuite ERPStripe & Adyen PaymentsEpic & Cerner EHR (FHIR/HL7)HubSpot & MarketoTwilio & SendGridWorkday & BambooHRPlaid Financial APIs
API Integration Methodology

A Secure 4-Phase API Engineering Process

From data schema modeling and OpenAPI contract specifications to sandbox mocking, load testing, and zero-downtime gateway rollout.

01
Weeks 1–2

Schema Discovery & Contracts

We map data entities, webhook triggers, rate limiting quotas, and draft formal OpenAPI 3.0 or GraphQL schema definitions before writing code.

Key Output:OpenAPI specifications & contract blueprints
02
Weeks 2–3

Sandbox Mocking & Auth Architecture

We deploy mock API servers, establish OAuth 2.0 / mTLS zero-trust auth tokens, and create developer sandbox environments to unblock frontend teams.

Key Output:Interactive sandbox & Postman collections
03
Weeks 3–5

Middleware & Resiliency Pipeline

We engineer high-speed data transformation middleware with exponential backoff retries, dead-letter queues, circuit breakers, and webhook workers.

Key Output:Fault-tolerant integration pipelines & queues
04
Production & Scale

Security Audit & Gateway Launch

We conduct OWASP API Top 10 penetration tests, execute k6 load benchmarks, configure Datadog metrics, and complete 100% intellectual property transfer.

Key Output:Live API gateway & 100% IP code transfer
Explore Our Complete Engineering Methodology →

Solutions Aligned with Your Business Goals

Explore how our end-to-end capabilities support your product journey—whether you’re building something new or evolving what already works.

Artificial Intelligence (AI) & Machine Learning (ML)

Artificial Intelligence (AI) & Machine Learning (ML)

Leverage advanced ML models and neural networks to extract insights, automate decisions, and drive business growth.

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Blockchain Development

Blockchain Development

Innovate securely with decentralized applications, smart contract design, and robust distributed ledger systems.

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Staff Augmentation

Staff Augmentation

Scale your engineering teams with top-tier developers, QA testers, and project managers tailored to your needs.

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WordPress Development

WordPress Development

Build high-performing, secure, and custom-designed WordPress websites with optimized user experiences.

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FinTech Software Solutions

FinTech Software Solutions

Develop secure, compliant, and highly scalable financial technologies, transaction systems, and bank-grade applications.

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Containerization & Infrastructure as Code

Containerization & Infrastructure as Code

Modernize your deployment pipelines with scalable containerization strategies and cloud-native automation.

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Ongoing Support & Maintenance

Our team provides dedicated post-launch support to ensure your applications continue running smoothly. From troubleshooting to updates, performance monitoring, and security patches, we’re here to help your business stay ahead.

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24/7 Support

We’re available when you need us to ensure uninterrupted operations.

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Security & Compliance

Regular audits and updates to protect your data and meet industry standards.

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Performance Monitoring

Continuous tracking to keep your applications running efficiently.

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Updates & Optimizations

Ongoing enhancements to keep your applications up-to-date and performing at their best.

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Expert Support & Transformation Services

Our team doesn’t just build and deploy your applications — we provide comprehensive support and strategic expertise to ensure your technology drives business success. From ongoing maintenance to project planning and process optimization, we help companies stay competitive and future-ready.

  • checkContinuous Monitoring of Your Systems – Ensure your applications remain online and fully operational by detecting and resolving issues before they impact users.
  • checkScheduled Maintenance & Optimizations – Keep your systems efficient and cost-effective with automated updates, performance tuning, and proactive improvements.
  • checkContinuous Deployment & Fixes – Maintain a secure, reliable, and competitive product with seamless updates, patches, and enhancements delivered without disruption.
  • checkPerformance & Reliability Insights – Gain real-time visibility into your application’s health, enabling data-driven improvements that boost user satisfaction and business results.

Forming strong and trusted connections with our clients

300+
Engineers
5
Global Offices
20+
Years of Experience
1500+
Successful Projects
4.5+
Customer Satisfaction

We harness our market-leading technical expertise to offer a full suite of set-up services, designed to help your vision become a thriving reality.

Custom API Integration & Gateway FAQs

Frequently asked questions on OpenAPI standards, GraphQL federations, OAuth 2.0 / mTLS security, and third-party enterprise integrations.

How do you handle API security, authentication, and rate limiting?

We implement zero-trust defense-in-depth security across all integration points. This includes mutual TLS (mTLS) for machine-to-machine communication, OAuth 2.0 with PKCE for user-facing applications, HMAC SHA-256 signatures for webhook verification, and distributed Redis token-bucket rate limiters to protect upstream backends from DDoS exhaustion.

Can you integrate legacy SOAP, XML, or on-premises databases with modern REST/GraphQL APIs?

Yes. We specialize in legacy middleware transformations. We build containerized translation proxies that ingest legacy SOAP payloads, proprietary EDI formats, or direct database views and transform them into standardized JSON OpenAPI 3.0 or GraphQL schemas, enabling modern frontends to communicate seamlessly with legacy infrastructure.

How do you ensure zero data loss when downstream third-party APIs experience outages?

We engineer event-driven asynchronous queuing systems using Apache Kafka, RabbitMQ, or AWS SQS. Payloads are persisted in durable message brokers with exponential backoff retries and dead-letter queues (DLQs). If a downstream CRM or payment provider goes offline, our pipelines buffer requests and replay them automatically once the third party recovers.

Who retains ownership of the custom API gateway source code and schemas?

You retain 100% full intellectual property ownership. All OpenAPI specifications, Postman test collections, gateway routing rules, and custom middleware microservices are committed directly to your organizations repositories with full documentation.

How quickly can we onboard a dedicated senior API architect or backend pod?

Our senior systems architects and backend developers can be onboarded into your repositories within 48 to 72 hours. Operating at our agreed rate card of $125/hr for senior developers and architects, they evaluate your API contracts and deliver production middleware in sprint 1.

What It’s Like to Work With Us

A look into the journey from idea to scale, shared by one of our most successful early-stage clients.

Built for Growth, Delivered with Speed 💪

"Exquisite Software helped us go from idea to launch fast. They understood our goals, built a solid MVP in under 4 months, and guided us through key product decisions. We hit $36K MRR in 6 months — couldn’t have done it without their insight, speed, and execution."

Alex Lawson

VP of Product at Contigen

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Alex Lawson

Let's Accelerate Your Project – From Concept to Launch

Fast and Efficient Custom App Development – Connect with Our Team Today to Transform Your Concept into a Fully Realized Product

Exquisite Software - Technology Solutions