Senior FastAPI Development AgencyFastAPI Agency
We ship FastAPI backends in 12 weeks. Fixed price, senior engineers only, async-first architecture.
IRPR is a senior FastAPI development agency. We build high-performance APIs using Python 3.12, async endpoints, Pydantic v2 for validation, SQLAlchemy 2.0 for ORM, and Celery for background tasks. Every project starts with a Roadmap phase where we define endpoints, data models, and async workflows before writing a line of code.
In 12 weeks we ship a production-ready FastAPI backend with OpenAPI docs, automated tests (pytest coverage > 90%), and a CI/CD pipeline on GitHub Actions. Pricing for a full MVP ranges from $80K to $250K depending on complexity and integrations (Stripe, Auth0, Kafka, Redis, etc.). All projects comply with relevant standards: HIPAA, PCI-DSS, or SOC 2 when needed.
We work with CTOs who need to validate a SaaS idea fast, engineering leads replacing a legacy Django or Flask API, fintech founders building a payment platform under PCI compliance, and healthcare startups needing HIPAA-compliant backend architecture.
Types of software we ship.
SaaS Backend API
Multi-tenant FastAPI backend with Stripe billing, rate limiting, and async task queues via Celery. Supports 10K+ concurrent users.
Real-time Data Pipeline
Event-driven FastAPI service using Kafka or RabbitMQ for stream processing. Ideal for IoT, fintech, or logistics data ingestion at scale.
Ecommerce Checkout API
FastAPI checkout service integrating Stripe, PayPal, and Shippo. Includes PCI-compliant payment tokenization and idempotency keys.
Healthcare FHIR API
HIPAA-compliant FastAPI backend for EHR integration using FHIR R4 standard. Supports SMART on FHIR auth and audit logging.
AI Model Serving API
Async FastAPI wrapper for LlamaIndex or OpenAI endpoints. Handles rate limiting, caching (Redis), and model fallback logic.
Admin Dashboard Backend
FastAPI admin panel with role-based access control (RBAC), audit trails, and export endpoints. Built with FastAPI Users and SQLAdmin.
Payment Processing Gateway
PCI-DSS compliant FastAPI gateway wrapping Stripe, Adyen, or Braintree. Supports webhook verification and idempotent refund flows.
Internal Tool API
FastAPI CRUD backend for internal operations with Swagger docs, Celery for report generation, and Slack/email notifications.
We build for every business type.
Fintech and payments
Healthcare and life sciences
Ecommerce and retail
SaaS and B2B platforms
Logistics and transportation
Why choose a senior FastAPI development agency
IRPR delivers FastAPI backends that power production systems at scale.
FastAPI is the Python framework of choice for high-performance APIs thanks to async support, automatic OpenAPI docs, and Pydantic validation. But building a production-grade FastAPI backend requires experience with async patterns, database connection pooling, efficient query optimization, and deployment pipelines. A senior FastAPI development agency like IRPR brings that expertise from day one.
Our senior engineers have shipped FastAPI backends for fintech platforms handling 10M+ daily requests, healthcare APIs processing HIPAA-protected data, and SaaS products serving 50K+ users. We use Python 3.12, PostgreSQL 16, Redis for caching, and Docker with Kubernetes for orchestration. Every project includes automated tests, CI/CD, and monitoring with Sentry and DataDog.
The IRPR difference for FastAPI projects
Generic dev shops ship mediocre APIs. IRPR ships production-ready FastAPI systems on time and on budget.
Most generic development agencies follow a slow waterfall process or use hourly billing that rewards inefficiency. They use dated libraries like Flask or Django REST Framework without async support. Their junior engineers write slow endpoints, ignore connection pooling, and produce untestable code.
IRPR uses FastAPI with async endpoints from day one. We write comprehensive pytest test suites with >90% coverage. Every project gets a fixed price after the Roadmap phase. Our senior engineers own the full stack - from API design to deployment on AWS ECS or Google Cloud Run. No handoffs, no delays.
- Hourly billing with no cost ceiling
- Junior engineers learning on your project
- Blocking I/O endpoints that scale poorly
- No automated tests or CI/CD
- Synchronous code for database queries
- Manual deployment with downtime
- Fixed price after 2-week Roadmap
- Senior engineers only, 10+ years each
- Async FastAPI endpoints from the start
- pytest coverage > 90%, CI/CD on GitHub Actions
- SQLAlchemy async sessions with connection pooling
- Zero-downtime deployments via Docker + Kubernetes
How we build your FastAPI backend in 12 weeks
Our process ensures you get a production-ready API fast with no surprises.
We follow a repeatable 4-phase process designed for speed and quality. Every phase has clear deliverables and a go/no-go decision point. You stay in control of priorities.
Phase 1 is a 1-week kickoff where we align on your API contract using OpenAPI specs. Phase 2 is the 2-week Roadmap where we produce a fixed-price proposal with exact endpoints, data models, and testing plan. Then we build in 8 weeks with bi-weekly demos. Phase 4 is a 1-week release with production deployment and documentation.
What ships with every FastAPI project
Every deliverable includes production-grade infrastructure and documentation.
When you partner with IRPR, you don't just get an API. You get a complete production system ready for real users. Our senior engineers ship everything needed for a reliable, maintainable backend.
From source code to deployment scripts, you own every line. We set up monitoring, error tracking, and performance alerts before launch. No hidden setup fees.
- Source code in your private GitHub repo
- CI/CD pipeline on GitHub Actions with automated tests
- OpenAPI 3.1 documentation hosted on Swagger UI
- pytest test suite with >90% code coverage
- Docker containers with docker-compose for local dev
- PostgreSQL database schema with Alembic migrations
- Redis caching layer for high-traffic endpoints
- Sentry error tracking and monitoring
- Deployment scripts for AWS ECS or Google Cloud Run
- Runbook with troubleshooting and rollback steps
What we ship in this practice.
Payment processing API for fintech startup
We built a PCI-compliant FastAPI backend handling 500K+ transactions monthly. The API integrated Stripe Connect, idempotency keys, and webhook verification. The client reduced payment failures by 35%. Tech stack: FastAPI, PostgreSQL, Redis, Stripe, Celery.
Telemedicine platform with video streaming
Our FastAPI backend managed 10K+ daily video consultations with HIPAA-compliant audit logging. Used async endpoints for real-time status updates and Celery for recording uploads. Reduced average API response time from 400ms to 80ms. Tech stack: FastAPI, PostgreSQL, Twilio Video, Celery, Redis.
Multi-vendor marketplace API
We developed a FastAPI backend for a marketplace with 50K+ products and 2000 vendors. Integrated search via Elasticsearch, inventory sync via webhooks, and split payments via Stripe Connect. Handled 2000 requests/second at peak. Tech stack: FastAPI, Elasticsearch, PostgreSQL, Stripe, RabbitMQ.
SaaS analytics platform API
Built a multi-tenant FastAPI backend serving 500+ business clients. Each tenant had isolated data with row-level security. Used async endpoints for real-time report generation. Reduced report generation time from 5 minutes to 45 seconds. Tech stack: FastAPI, PostgreSQL, Redis, Celery, Snowflake.
Real-time logistics tracking system
We created a FastAPI backend that processed 50K+ GPS events per second from fleet vehicles. Used async FastAPI with Kafka for event streaming and Redis for geofencing. Achieved 99.99% uptime and sub-100ms latency for driver location updates. Tech stack: FastAPI, Kafka, Redis, PostgreSQL, Google Maps API.
AI-powered content moderation API
Our FastAPI service wrapped OpenAI and LlamaIndex models for automated content moderation. Handled 100K+ requests daily with rate limiting and model fallback. Achieved 40% cost reduction by caching common queries in Redis. Tech stack: FastAPI, Redis, PostgreSQL, OpenAI, LlamaIndex.
Why teams hire us.
Senior engineers only, 10+ years each
Every engineer at IRPR has at least 10 years of production experience. No juniors or interns touch your code. Our team includes former lead architects from top tech companies.
Fixed price, not hourly
We give you a fixed price after the 2-week Roadmap phase. No hourly billing, no surprise invoices, no scope creep charges. You know the budget before we write code.
12-week MVP delivery guarantee
From kickoff to production, your FastAPI backend ships in 12 weeks. We have shipped 200+ products on time. If we are late, you get a 10% discount on the final invoice.
Full code ownership and no lock-in
You own all source code, Docker files, CI/CD pipelines, and documentation. We never use proprietary frameworks or code generators. You can walk away at any time with everything.
Production-grade infrastructure from day one
Every project ships with CI/CD, automated tests, Sentry error tracking, and monitoring. No technical debt. No manual deployment scripts. Your API goes live with enterprise reliability.
HIPAA, PCI, and SOC 2 compliance built in
We build compliance into your FastAPI backend from the start. Our team has delivered HIPAA-compliant systems for 20+ healthcare clients and PCI-compliant APIs for 15+ fintech companies.
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.
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