Senior Custom API Development AgencyAPI Development
We build production-grade APIs for your core business logic. Fixed price, 8-12 weeks to first release.
IRPR builds custom APIs that power your products. We use Node.js, Python, Go, PostgreSQL, Redis, and Docker to build RESTful and GraphQL endpoints. Every API includes versioning, rate limiting, and monitoring from day one.
A typical API project ships in 8-12 weeks with a fixed price range of $80K to $250K. We handle compliance including SOC 2, HIPAA, PCI-DSS, and GDPR. You get full ownership of the code and a CI/CD pipeline on GitHub Actions.
Clients include CTOs integrating legacy systems into microservices, product owners launching API-first platforms, fintech startups needing PCI-compliant payment APIs, and healthcare companies requiring HIPAA-compliant patient data APIs.
Types of software we ship.
Payment gateway API
Process transactions with Stripe or Braintree. Handles idempotency, webhooks, and PCI compliance out of the box.
Data aggregation API
Pull data from multiple sources into a single endpoint. Uses Redis caching and PostgreSQL for fast reads.
SMS / notification API
Send SMS via Twilio, push via Firebase, and email via SendGrid. Includes delivery tracking and templating.
Authentication API
OAuth 2.0, SSO, and JWT-based auth with Okta or Auth0. Supports social login and multi-tenancy.
E-commerce inventory API
Manage product catalog, stock levels, and orders across Shopify, WooCommerce, and custom backends.
Real-time chat API
WebSocket-based chat with Socket.io or AWS WebSocket API. Supports message history, typing indicators, and file uploads.
Location-based services API
Geofencing, maps, and routing using Google Maps Platform and OpenStreetMap. Optimized for mobile queries.
Document processing API
Parse, generate, and convert PDFs, Word docs, and images. Uses AWS Lambda for serverless scaling and Tesseract for OCR.
We build for every business type.
Fintech
Healthcare
E-commerce
SaaS
Logistics
Why choose a senior custom API development agency?
Most offshore teams deliver broken endpoints. We deliver production-ready APIs.
IRPR has shipped over 200 APIs across 50 countries. Our senior engineers average 10+ years of backend experience. Every project includes automated load testing, error tracking with Sentry, and uptime monitoring with Datadog.
We build for scale from the start. Rate limiting with Redis, database connection pooling with PgBouncer, and auto-scaling on AWS or GCP. Post-launch we provide 3 months of support and a clear handover to your team.
The difference between amateur and senior API development
Not all API developers work the same. Here is what sets IRPR apart.
Generic dev shops often skip fundamentals: no versioning, inconsistent error formats, no rate limiting, and no monitoring. You get a black box that breaks in production. Billing is hourly, so costs balloon when unexpected work appears.
IRPR treats API development as an engineering discipline. We version every API from day one. We use RFC 7807 for errors, rate limit with Redis, monitor with Sentry and Datadog, and document with OpenAPI. Price is fixed from the Roadmap phase.
- No API versioning
- Inconsistent error responses
- No rate limiting
- No monitoring or alerting
- No documentation
- Hourly billing with scope creep
- API versioning from day one
- RFC 7807 error format
- Rate limiting with Redis
- Sentry + Datadog monitoring
- OpenAPI / Swagger docs
- Fixed price, no surprises
How we build your custom API in 12 weeks
We follow a proven 4-phase process that delivers a production-ready API on schedule.
Phase 1 is the Roadmap (week 2). We define endpoints, data models, integrations, and produce a fixed price quote. Phase 2 is core development: we build the API with unit tests, integration tests, and a staging environment on AWS.
Phase 3 is load testing and hardening. We run k6 or Artillery tests, fix bottlenecks, and set up monitoring. Phase 4 is deployment and handover: we deploy to production, write runbooks, and train your team.
What ships with every custom API project
You own everything. No lock-in, no hidden dependencies.
Every project includes the complete source code in your repository, a CI/CD pipeline on GitHub Actions or GitLab CI, and Docker containers for local and production environments. We also deliver a Postman collection for easy testing.
Our APIs come with load test reports from k6 or Locust, deployment scripts for AWS or GCP, and a monitoring dashboard in Datadog or Grafana. You get a runbook that explains how to scale, debug, and update the API.
- Source code in your private GitHub/GitLab repo
- CI/CD pipeline (GitHub Actions or GitLab CI)
- Docker containers for development and production
- API documentation (OpenAPI / Swagger UI)
- Postman collection with example requests
- Load test report (k6 or Artillery)
- Deployment scripts for AWS or GCP
- Monitoring dashboards with Datadog or Grafana
- Sentry error tracking integration
- Runbook for operations team
What we ship in this practice.
Payment processing API for a fintech startup
Built a PCI-compliant payment API that reduced transaction failure rate from 3% to 0.5%. Handles 500 requests per second during peak. Stack: Node.js, PostgreSQL, Stripe, AWS Lambda.
Patient data exchange API for a telehealth platform
Created a HIPAA-compliant FHIR API that connects 20 clinics. Reduced appointment scheduling time by 12 minutes per patient. Stack: Python, FastAPI, PostgreSQL, Twilio, AWS ECS.
Multi-vendor inventory API for a marketplace
Aggregated inventory from 150+ suppliers into a single API. Cut inventory sync latency from 30 minutes to 15 seconds. Stack: Node.js, Redis, PostgreSQL, Shopify API, RabbitMQ.
User authentication and SSO API for a SaaS platform
Built OAuth 2.0 and SAML SSO integration supporting 10,000+ users. Reduced login support tickets by 40%. Stack: Go, OAuth, Okta, PostgreSQL, AWS Cognito.
Geofencing and route optimization API for a delivery startup
Developed location-based services API that optimized delivery routes, saving 20% on fuel costs. 200,000+ requests per day. Stack: Node.js, Google Maps API, MongoDB, Redis, AWS SQS.
Document generation API for an insurance broker
Automated PDF generation for policy documents, reducing manual work by 8 hours per week. Generates 500 policies per hour. Stack: Python, Flask, PostgreSQL, WeasyPrint, AWS Lambda.
Why teams hire us.
Fixed price, not hourly
Every project gets a fixed quote in the Roadmap phase (week 2). No hourly billing, no surprise invoices, no scope creep charges. If we add endpoints, you approve before we work.
Senior engineers only
All IRPR engineers have 10+ years of experience. No junior devs learning on your project. We use proven patterns like repository, service layer, and event-driven architecture.
Full code ownership
You own 100% of the source code, documentation, and infrastructure. We deploy to your cloud accounts. No lock-in, no licensing fees.
Compliance built in
We handle SOC 2, HIPAA, PCI-DSS, and GDPR from day one. Our APIs include audit logging, encryption at rest, and role-based access control.
US-based team, async-first
Project managers and most engineers work in US time zones. We use Slack, Linear, and Notion for daily async updates. Weekly video calls for demos.
Post-launch support included
Every project includes 3 months of post-launch support. We fix bugs, answer questions, and help your team take over. After that, you can extend support monthly.
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.