We deliver API development and integration services built for scale. Design, build, and secure REST, GraphQL, SOAP, and WebSocket APIs that connect your systems, apps, and third-party platforms.
API development and integration services spanning REST, GraphQL, SOAP web services, webhooks, and middleware. We link your systems to platforms like Stripe, Salesforce, and SAP through production-grade API integration.
Book Consultation NowAn API (Application Programming Interface) is a contract that lets two systems exchange data over endpoints, typically using REST with JSON payloads, GraphQL queries, or SOAP messages over HTTP.
API development means building a new API from scratch. API integration connects existing APIs to each other. Most real projects need both, delivered as one solution.
Strategy, design, build, modernize, manage. Eight focused API development services covering the full lifecycle from first endpoint to 24/7 production support.
First, we run strategy and architecture assessment, and produce an API roadmap aligned to business KPIs.
Explore consultingSpecifically, we design REST, GraphQL, SOAP, WebSocket, and gRPC APIs tailor-made for your stack.
For example, we connect Stripe, Salesforce, Shopify, SAP, Twilio, FedEx, and OpenAI with resilient error handling.
Salesforce integrationAdditionally, we migrate SOAP to REST or GraphQL and modernize outdated APIs with zero downtime.
Legacy integrationAs a result, monoliths are decomposed into modular, independently deployable services with clean domain boundaries.
Enterprise softwareFurthermore, gateway setup, rate limiting, API versioning, analytics, and real-time monitoring run across environments.
In practice, functional, performance, security, and contract testing are wired into CI/CD pipelines.
Finally, we provide ongoing monitoring, patching, scaling, and SLA-backed support across time zones.
Every vertical has its own compliance rules, data models, and integration stack. Our domain-specialized engineers ship API integration services built to each industry's realities, from HIPAA and PCI-DSS to GDS protocols and IoT device connectivity.
Core banking, payments, KYC, and open-banking APIs built to PCI-DSS and PSD2 standards.
See fintech work
HIPAA-compliant EHR, telemedicine, FHIR, and medical-device integration APIs.
View healthcare work
Storefront, payment gateway, shipping, and inventory-sync APIs for Shopify, Magento, and WooCommerce.
See eCommerce work
Real-time tracking, multi-carrier, and fleet-management APIs covering FedEx, UPS, and DHL.
View logistics work
GDS, booking-engine, hotel, and flight-supplier APIs with dynamic-packaging logic.
Discover travel work
LMS, assessment, video, and proctoring APIs with SCORM and xAPI compatibility.
View EdTech work
Device, SCADA, MES, and ERP connectivity APIs with MQTT and OPC-UA support.
See manufacturing work
MLS, property-listing, virtual-tour, and CRM integration APIs for residential and commercial brokers.
View real estate workA repeatable methodology refined across 500+ engagements. Every step is sprint-based, tool-specific, and built around API lifecycle management from first endpoint to long-term versioning.
First, stakeholder workshops translate your business goals into a clear API plan covering endpoints, data flows, and success metrics.
We design and document the full API blueprint, then review it with your team so there are no surprises later.
We pick the right protocol for your use case (REST, GraphQL, or gRPC) and lock in authentication and compliance from day one.
Then, we build in 2-week sprints with code reviews on every change, so quality is verified continuously, not at the end.
We test the API end-to-end for performance, security, and reliability before anything touches your production systems.
We launch with zero-downtime releases and automatic rollback, so your users never see disruption when updates ship.
We monitor your API 24/7, respond to issues fast under SLA, and manage versioning as your business evolves.
Production deployments across logistics, fintech, and travel. Each engagement shipped on REST APIs, multi-vendor integrations, and custom middleware built for measurable business outcomes.
Logistics · AITransworld handled 2,000+ invoices daily across disconnected systems and inconsistent formats. We built an API-first document processing platform that extracts, validates, and pushes structured JSON directly into their ERP and accounting stack.
Fintech · BNPLBuilt the API layer powering a Buy Now Pay Later lending app, connecting payment gateways, installment scheduling, and in-app transaction tracking. Simplified the checkout flow so users complete BNPL transactions without friction.
Travel · Multi-VendorIntegrated GDS flight APIs (Amadeus, Sabre, Travelport), hotel suppliers (Booking.com, Expedia, HotelBeds), payment gateways, and maps into a single travel booking app with caching, retries, and safe fallbacks for supplier downtime.
We pick the right tool for the job, not a one-size-fits-all stack. Every engagement is engineered on production-proven technologies that power our end-to-end API gateway services, security, and cloud deployments at scale.
Battle-tested runtimes for microservices and enterprise-scale APIs.
Full protocol matrix from public REST to internal gRPC meshes.
Routing, rate limiting, and versioning at production scale.
Zero-trust identity layered across every API endpoint by default.
Relational, document, cache, and search stores for any access pattern.
Multi-cloud deployment with containers and infrastructure-as-code.
Contract and load testing with auto-generated developer portals.
Real-time metrics, distributed tracing, and alerting across every call.
Enterprise API development services built on proven engineering, strict compliance, and transparent delivery. Five concrete reasons teams pick SDLC Corp over the alternatives.
500+ APIs running in production, 150+ API engineers on staff, and 12 years building for fintech, healthcare, logistics, and SaaS teams worldwide.
HIPAA, PCI-DSS, GDPR, SOC 2, and ISO 27001 alignment baked into every API. In addition, zero-trust authorization and OWASP API Top 10 controls are default.
99.99% uptime SLA, horizontal scaling, and zero-downtime blue-green deployments. As a result, our APIs handle Black-Friday traffic spikes without paging anyone.
USA, UK, UAE, Qatar, India, Australia, and Canada. For example, round-the-clock engineering across 3 time zones keeps your project moving while competitors sleep.
Daily standups, Friday sprint demos, and 100% source-code handover with no vendor lock-in. You own the IP and infrastructure from day one of the engagement.
Verified reviews pulled directly from Clutch and GoodFirms. Every name, company, and star rating below is traceable to its original third-party source.
SDLC Corp delivered what they promised, which is something that is missing nowadays. They stuck to the timeline, delivered an exceptional product as per expectation, and we still look forward to consuming more of their services.
Their ability to complete the various stages of the project at specified timeframes impressed us very much. Their technical knowledge in blockchain, React, and Node development converted our idea into a working product.
They saw inefficiencies in our processes that we had stopped noticing, and built a solution. Working with SDLC Corp was a smooth, transparent, and professional experience from day one of the engagement.
API development costs vary based on complexity, third-party integrations, security, and timelines, not a flat rate card. Based on 500+ APIs we've delivered as an API development and integration company, here are the typical 2026 ranges you can plan against. Specifically, the table below maps project type to estimated cost and timeline.
| Project Type | Estimated Range | Timeline |
|---|---|---|
| Simple REST APIA focused API for a single product or feature. | $5K – $15K | 3–6 weeks |
| Third-party integration (single platform)Connecting your app to one external service like Stripe, Salesforce, or Shopify. | $3K – $20K | 2–8 weeks |
| Multi-system integration (CRM + ERP + Payment)Linking several business tools so data flows between them automatically. | $20K – $80K | 2–5 months |
| Enterprise API platform & gatewayA central hub that hosts, secures, and manages all your APIs at scale. | $50K – $250K+ | 4–9 months |
| Legacy API modernizationRebuilding or replacing older APIs with secure, modern architecture. | $40K – $150K | 3–8 months |
Hands-on guides and integration playbooks written by our senior architects. Real technical depth on Salesforce, QuickBooks, and WhatsApp API integrations you can apply to your next build.
REST · Integration
Finance · API
Messaging · APIStraight answers from our senior API architects on development, integration, security, compliance, and cost. Written for technical leads and engineering decision-makers.
API development is the process of designing and building a brand-new API, defining endpoints, data contracts, authentication, and business logic so other systems can consume your service.
API integration is the process of connecting existing APIs (yours, a partner's, or third-party SaaS like Stripe or Salesforce) to your systems so data and actions flow between them reliably. Most enterprise projects need both.
REST is stateless and resource-oriented, the common default for public web APIs. SOAP is an older XML-based protocol still used in banking and telco for its strong contracts.
GraphQL lets clients request exactly the fields they need in one call, reducing over-fetching for mobile and frontend apps. In practice, gRPC uses Protocol Buffers and HTTP/2 for fast internal service-to-service calls, typical in microservices.
Custom API development in 2026 ranges from $5K for a simple REST API to $250K+ for enterprise API platforms.
Typically, a single third-party integration falls between $3K and $20K, multi-system integrations run $20K to $80K, and legacy modernization lands around $40K to $150K. See the pricing table above for the complete 2026 breakdown.
A single REST endpoint with authentication and documentation ships in 3 to 4 weeks. A multi-endpoint API with third-party integrations takes 6 to 12 weeks.
An enterprise API platform with gateway, observability, multi-region deployment, and compliance audits typically runs 4 to 9 months. We deliver in 2-week sprints with demos every Friday so stakeholders see progress continuously.
We enforce the OWASP API Security Top 10 by default: OAuth 2.0 and JWT with short TTLs, object and function-level authorization, schema validation, gateway-level rate limiting, TLS 1.3 everywhere, mTLS between internal services, secret rotation, full audit logging, and DAST/SAST scans in the CI/CD pipeline.
Enterprise clients also get quarterly penetration tests.
Yes, this is one of our most-requested engagements. We typically place a modern REST or GraphQL facade in front of your SOAP endpoints, translate WSDL contracts into OpenAPI 3.1, and migrate consumers progressively using strangler-fig patterns.
That means zero big-bang cutovers and zero downtime. For regulated industries we preserve full audit trails during the migration.
Compliance is designed in, not bolted on. HIPAA: BAAs, field-level encryption for PHI, strict access controls, and retained audit logs. PCI-DSS: cardholder data stays out of your systems through tokenization via certified processors, with infrastructure scoped accordingly.
GDPR: data-subject-access endpoints, right-to-erasure, and consent tracking built directly into the API. Also aligned to SOC 2 and ISO 27001.
Every API we ship comes with OpenAPI 3.1 documentation, an interactive Swagger or Redoc developer portal, Postman collections, and optional client SDKs.
Post-launch we offer SLA-backed managed services including 24/7 monitoring with Datadog or New Relic, incident response, security patching, version upgrades, and capacity scaling, plus a dedicated account manager.
United States:
Transform Digital LLC
44 Montgomery Street, Suite 300
San Francisco, CA 94104
United Kingdom:
30 Charter Avenue, Coventry
CV4 8GE Post code: CV4 8GF United Kingdom
United Arab Emirates:
Unit No: 729, DMCC Business Centre Level No 1, Jewellery & Gemplex 3 Dubai, United Arab Emirates
India:
715, Astralis, Supernova, Sector 94 Noida, Delhi NCR India. 201301
Qatar:
B-ring road zone 25, Bin Dirham Plaza building 113, Street 220, 5th floor office 510 Doha, Qatar
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