FastAPI Backend Engineering
High-throughput, asynchronous Python backends engineered for concurrent workloads, PostgreSQL tenant isolation, and rock-solid operational reliability.
The Architectural Bottleneck
Synchronous blocking I/O causes requests to queue up during heavy webhook spikes or AI token streaming. Loose types cause runtime crashes, and vague database queries leak cross-tenant customer data.
The Async Solution
Typed, fully asynchronous backends with FastAPI and Pydantic v2. Connection-pooled asyncpg queries, background task workers, and PostgreSQL Row-Level Security (RLS) enforcing strict tenant partition at the database engine level.
What We Engineer
Non-blocking endpoints designed for high concurrency, real-time live events, and streaming AI model responses.
Tenant isolation enforced natively in PostgreSQL using Row Level Security policies and session tenant context variables.
OAuth2 password bearer flows, JWT validation, refresh token rotation, and granular role permissions.
Comprehensive Pytest test fixtures, Alembic migration management, and production-ready Docker containers.
Backend Stack & Standards
Async by Design
Native async/await event loops handling thousands of open connections without worker starvation.
Strict Type Safety
Pydantic v2 schemas validating request inputs and responses with automatic OpenAPI specifications.
Database Optimization
Connection pooling via SQLAlchemy 2.0 / SQLModel with indexed queries and zero N+1 bottlenecks.
Engineered Multi-Tenant Backends
From TarkaBot's multi-branch restaurant ordering engine with PostgreSQL RLS to Waraq AI's async vector ingestion pipelines, Ahsaan has engineered backends with automated test suites, connection pooling, and Docker deployments.
How We Deliver (1–2 Weeks)
- Day 1–2: Data model design, schema normalization, and API endpoint contracts.
- Day 3–7: Async endpoint implementation, auth flows, and RLS policies.
- Day 8–10: Pytest suites, load verification, and database index tuning.
- Day 11–14: Docker packaging, CI/CD pipeline, and deployment handover.
Transparent Scoped Pricing
Priced by sprint scope or feature deliverable. Complete handover includes clean source code, database migration scripts, test suites, and Docker files.
Frequently Asked Questions
Why choose FastAPI over Django or Express for AI applications?
FastAPI is asynchronous by default, making it ideal for non-blocking I/O operations such as streaming LLM responses, processing webhooks, and managing concurrent database pools without thread lock.
How do you ensure multi-tenant security in the database?
We enforce PostgreSQL Row Level Security (RLS) policies at the database layer. Even if application code has a query bug, database-level tenant isolation prevents one customer from ever accessing another tenant's records.
Do you provide automated tests and Docker containerization?
Yes. Every API project includes pytest integration suites with database fixtures, automatic OpenAPI/Swagger documentation, and a multi-stage Dockerfile ready for deployment on any cloud provider.
Can you integrate with existing frontends (React, Next.js, Mobile)?
Yes. We design strictly typed REST or WebSocket APIs using Pydantic v2 schemas that cleanly serialize to TypeScript interfaces for your frontend team.
What is your typical engagement model?
We work on both fixed-price milestone sprints (e.g. 1–2 week MVP backends) and dedicated monthly engineering retainers.
Need an asynchronous backend that handles real loads?
Let's review your data model and build an API that will not choke under concurrency.