Best REST API Development Agency for Scalable SystemsREST API
We ship production-ready APIs in 8-12 weeks. Senior engineers only, fixed price, full code ownership.
IRPR builds REST APIs for applications that need to scale, integrate, and stay secure. We use Node.js, Python (FastAPI, Django), Go, and PostgreSQL or MongoDB depending on your data model and traffic patterns.
A typical REST API MVP ships in 8 to 12 weeks with costs between $80K and $250K. Every project includes compliance coverage for HIPAA, PCI-DSS, or SOC 2 if your industry requires it.
CTOs replacing legacy SOAP or custom integrations, startup founders launching API-first SaaS products, enterprise teams building microservices, and product managers connecting third-party tools all hire IRPR to own the API layer.
Types of software we ship.
Payment Gateway APIs
Stripe Connect or Adyen integration with idempotency keys and webhook replay. Handles PCI-DSS scope natively.
CRM Integration APIs
Two-way sync with Salesforce, HubSpot, or custom endpoints using RESTful patterns and OAuth 2.0.
Ecommerce Backend APIs
Product catalog, cart, checkout, and order management APIs backed by PostgreSQL and Redis for caching.
Healthcare FHIR APIs
HIPAA-compliant REST interfaces for patient records, appointment scheduling, and lab results using FHIR R4.
Real-Time Data APIs
WebSocket and REST hybrid for live dashboards, notifications, and streaming analytics using Firebase or AWS AppSync.
Mobile App Backend APIs
REST endpoints optimized for mobile clients with pagination, offline support, and push notification integration.
IoT Device APIs
M2M communication over REST with device authentication, telemetry ingestion, and OTA update triggers.
Data Aggregation APIs
Layer that normalizes data from 10+ sources into a single RESTful interface, with caching and rate limiting.
We build for every business type.
SaaS companies
Financial services
Healthcare
Ecommerce & retail
Media & content
REST API Development by the Numbers
Our track record shows what to expect when you hire IRPR for your REST API project.
We have shipped over 200 products across 50 countries since 2016. 98% of our projects delivered on time with zero scope creep because we use a fixed-price Roadmap phase.
APIs built by IRPR maintain 99.9% uptime in production. We deploy on AWS with multi-region redundancy, auto-scaling, and 24/7 monitoring via Datadog and PagerDuty.
Why Generic Dev Shops Fail at REST APIs
Most agencies treat API development like any other feature. We treat it as the core product.
Generic shops start coding without a clear contract. They bill by the hour, change specs mid-project, and often don't document endpoints. You end up with broken integrations, no tests, and no way to onboard new developers.
IRPR begins every REST API project with a 2-week Roadmap phase that defines every endpoint, data model, authentication method, and error code. You sign off on a fixed price and a 12-week delivery date before we write a single line of production code.
- Hourly billing with no cap
- No written API contract before build
- Junior or mixed-skill teams
- Minimal documentation (if any)
- No load testing
- Vague code ownership terms
- Fixed price after Roadmap phase (week 2)
- OpenAPI 3.0 spec signed off before coding
- Senior engineers only (10+ years average)
- Auto-generated docs (Swagger/Redoc)
- Load tests with k6 or Artillery
- Full code ownership, delivered in your repo
How We Build Your REST API in 12 Weeks
Four phases, clear milestones, no surprises.
Our process is designed to move fast without breaking things. Every phase has a deliverable you can review and approve before the next step begins.
We use agile sprints internally, but you see progress as milestone-based checkpoints, not daily standups. This keeps the project predictable and the team focused.
What Ships with Every REST API Project
Everything you need to run, maintain, and scale your API.
We don't just hand over code. Every IRPR REST API project includes production-grade tooling and documentation so your team can take over immediately.
- Source code in your private GitHub/GitLab repo
- OpenAPI 3.0 specification (YAML/JSON)
- Auto-generated Swagger UI and Redoc docs
- Unit and integration test suite (>90% coverage)
- CI/CD pipeline on GitHub Actions or CircleCI
- Load tests (k6) with baseline thresholds
- Postman collection with sample requests
- Docker Compose and Helm charts for local/staging/prod
- Sentry error tracking and Datadog monitoring dashboards
- Deployment runbook and architecture document
What we ship in this practice.
Payment Gateway API for Fintech Startup
Built a REST API that connects Stripe Connect with a custom invoicing system. Reduced transaction failures by 15% through idempotency keys and automatic retries. Tech stack: FastAPI, PostgreSQL, Redis, Stripe API.
Patient Appointment Booking API
Developed a HIPAA-compliant REST API for a telemedicine platform handling 10,000 appointments/day. Integrated with Epic EHR via FHIR R4. Tech stack: Django REST Framework, PostgreSQL, Twilio for SMS reminders.
Product Catalog API for Ecommerce Marketplace
Created a RESTful catalog API serving 50,000 products with faceted search and real-time inventory. Reduced page load time by 40% using Redis caching. Tech stack: Node.js, Express, MongoDB, Elasticsearch.
CRM Sync API for SaaS Platform
Built a two-way REST sync between HubSpot and a custom CRM that normalized 200+ fields. Cut manual data entry by 6 hours per week per sales rep. Tech stack: Python, FastAPI, HubSpot API, Celery for background jobs.
Real-Time Analytics API for Media Platform
Designed a REST/WebSocket hybrid API delivering viewer metrics with sub-second latency. Scaled to 1 million concurrent connections using AWS AppSync and DynamoDB. Tech stack: Node.js, GraphQL subscriptions, DynamoDB, Lambda.
Device Telemetry API for IoT Fleet
Implemented a REST ingestion API for 50,000 IoT devices sending telemetry every 5 seconds. Achieved 99.95% uptime with multi-region deployment. Tech stack: Go, TimescaleDB, RabbitMQ, Grafana dashboards.
Why teams hire us.
Fixed Price, Not Hourly
We set a fixed price after the 2-week Roadmap phase. No hourly billing, no surprise invoices, no scope creep charges. You know the cost before any development starts.
Senior Engineers Only
Every project is staffed with engineers averaging 10+ years of experience. No juniors, no offshore mismatch. Our team includes ex-Amazon, ex-Stripe, and ex-Uber engineers.
Full Code Ownership
You own every line of code, every test, every script. We never license our work. The source code is delivered in your repository with a permissive license (MIT or Apache 2.0).
Compliance Built In
We handle HIPAA, PCI-DSS, and SOC 2 requirements as part of the build. Our APIs include audit logs, encryption at rest (AES-256), and role-based access controls by default.
99.9% Uptime Guarantee
We deploy on AWS with multi-region failover, auto-scaling groups, and 24/7 monitoring. Our SLAs guarantee 99.9% uptime, and we provide monthly reports via Datadog.
Start in 1-2 Weeks
We begin the Discovery phase within 7 business days of signing a mutual NDA. Most Roadmap phases complete in 14 days, and development starts immediately after you approve the spec.
Idea → Roadmap → Product → Release.
Every engagement runs through the same four-stage pipeline. Predictable by design.
Questions clients ask first.
Related services and industries.
Ready to build? Let's talk.
30-minute discovery call. No deck. We'll tell you honestly what it takes, how long, and how much.