FastAPI Development Services for Canadian SaaS, AI, and Data Teams
FastAPI development is the building of high-performance, async Python APIs and microservices with the FastAPI framework, the service layer modern SaaS, data, and AI products run on. MicroPyramid has 12+ years of Python and API work and ships these for Canadian startups and SMBs: async APIs, microservices, and ML/LLM serving layers built for real concurrency.
Why Canadian Teams Choose Us for FastAPI
Three reasons Canadian founders and product teams pick MicroPyramid over a local agency or a generic offshore team
Privacy-Aware APIs, Data in Canada
We design the API surface, logging, data retention, consent flows, and third-party calls with privacy in mind, including transparency for automated decisions, which directly shapes AI and ML inference endpoints. AWS ca-central-1 (Montreal) is available for Canadian data residency.
CAD Billing via Stripe
Invoices in Canadian dollars, collected via Stripe. No currency conversion friction, no international wire fees. Clean, predictable billing that fits how Canadian SaaS companies operate and budget.
Clear Ownership, Not a Ticket Mill
Our engineers directly own every engagement. You will not be passed to a delivery layer of junior developers. The engineer who scopes your API in discovery is the one who builds it.
Canadian APIs and Integrations We Build With FastAPI
Canadian products bill through Stripe, sell to enterprises that expect single sign-on, call LLM providers, connect to provincial health systems and accounting platforms, and serve two official languages. These are the integrations we build most often for Canadian teams, and what doing them properly involves.
Stripe and Payment Webhooks
Subscriptions and one-off charges in CAD through Stripe or a similar provider
Most Canadian SaaS products bill through Stripe or a comparable provider, and the hard part is keeping your own records in step with it, not the checkout page. We build a FastAPI billing service that verifies every webhook, uses idempotency keys so a retry never charges twice, tracks subscription state, handles refunds, and reconciles against the provider every night.
- Signed webhook verification and replay protection
- Idempotency keys on every charge and refund
- Subscription state, trials, and plan changes in CAD
- Nightly reconciliation job against provider records
Identity and Single Sign-On
Auth0, Amazon Cognito, Microsoft Entra ID, Google Workspace
Canadian enterprise and public-sector buyers increasingly ask for single sign-on before they sign. We connect FastAPI to Auth0, Amazon Cognito, Microsoft Entra ID, or Google Workspace over OAuth 2.0 and OpenID Connect, validate JWTs on every request, and map identity-provider groups to roles inside each tenant.
- JWT validation with signing-key rotation handled
- Tenant-aware roles and permissions
- Per-customer SSO setup for enterprise accounts
- Audit trail of logins and permission changes
LLM and AI Provider APIs
OpenAI, Anthropic, AWS Bedrock, or self-hosted models
Few Canadian teams want to bet their product on one model vendor. We put OpenAI, Anthropic, AWS Bedrock, or self-hosted models behind a single FastAPI layer that streams responses, retries and falls back across providers, enforces token budgets, and logs cost per tenant. Prompts and responses are logged with personal information redacted, and every provider call that leaves Canada is documented.
- Streaming responses over server-sent events
- Provider fallback with retries and timeouts
- Token budgets and per-tenant cost logging
- Prompt and response logs with personal data redacted
Bilingual English and French APIs
English and French for Quebec and federal users
If you serve Quebec, French is not optional for consumer-facing content, including contracts, commercial communications, and product information. We build APIs that negotiate language through Accept-Language, store translatable content per locale, send French notifications, and sort and search accented text correctly.
- Accept-Language negotiation with locale fallback
- Per-locale content fields in Pydantic models
- French error messages, emails, and notifications
- Accent-insensitive search and correct collation
Provincial Health Interoperability
FHIR and provincial health systems
Canadian health data is managed provincially, and interoperability is moving to FHIR through national and provincial specifications. We build FHIR-based FastAPI services, keep personal health information in Canada, and log every access, ready for the privacy impact assessments health partners expect.
- FHIR R4 resources and validation
- Canadian-hosted health data stores
- Access audit logging per record
- PIA-ready data flow documentation
Accounting Platform Sync
QuickBooks Online, Xero, Sage
Canadian invoicing details vary by province. We build FastAPI sync services against QuickBooks Online, Xero, and Sage with province-aware invoice fields, OAuth token rotation, and rate-limit-aware queues, so invoices and payments stay consistent across systems.
- Province-aware invoice fields and validation
- OAuth token storage and rotation
- Rate-limit-aware background sync
- Per-tenant sync status your support team can see
Our FastAPI Development Services
Six services covering the full lifecycle of high-performance Python APIs, from async builds and microservices to ML serving and migration
High-Performance Async APIs
Async FastAPI services for Canadian SaaS, proptech, and AI products that call LLM providers, partner APIs, and data sources in parallel. Async I/O keeps a slow upstream from stalling every other request, which matters most on sign-up, checkout, and AI response paths.
- Async/await concurrency
- Pydantic v2 validation
- Automatic OpenAPI docs
Microservices Architecture
Split a Canadian platform into services with clear boundaries: billing, identity, notifications, AI inference, and reporting. Keeping Quebec and health data flows in their own services makes privacy assessments and audits far simpler.
- Regulated-data isolation
- Docker and Kubernetes
- REST plus event queues
AI & ML / LLM Serving APIs
Streaming LLM endpoints, RAG services, and model-serving APIs with built-in transparency for automated decisions: a notice to the person, the main factors behind the decision, and a route to human review. Bilingual prompts and responses where your users need them.
- Model and LLM serving
- Server-sent event streaming
- Decision logs and review routes
Migration to FastAPI
Move legacy Flask, Django REST, or synchronous APIs onto async FastAPI endpoint by endpoint, behind the same URLs your Canadian customers and partners already call. Contract tests prove each cut-over, including French responses, before traffic moves.
- Phased, low-downtime migration
- Contract tests in both languages
- Performance audit first
Maintenance & Support Retainers
Security patching, dependency upgrades, third-party and LLM provider API changes, and feature work for FastAPI services in production, owned by dedicated engineers rather than a ticket queue.
- Security and dependency updates
- Provider version upgrades
- Feature work alongside your team
Cloud Deployment & DevOps
Deploy FastAPI to AWS ca-central-1 (Montreal) when Canadian data residency matters, with ca-west-1 (Calgary) available as a second Canadian region. CI/CD, structured logs, tracing, and infrastructure as code your auditors can read.
- AWS ca-central-1 (Montreal) deployment
- CI/CD with GitHub Actions
- Infrastructure as code
FastAPI, Django REST, or Flask? How to Choose
The three frameworks solve different problems, and real Canadian products often mix them. Here's the honest version, so you pick the right tool instead of the trendy one. We help you make the call in discovery, before any budget is committed.
Choose FastAPI when…
- You need a high-performance, type-safe API or microservice
- You're serving AI/LLM features, RAG endpoints, or heavy async I/O
- OpenAPI-first contracts and Pydantic validation are priorities
- You want a lightweight service, not a full web framework
Choose Django REST when…
- You want a full web app (admin, auth, and ORM) plus its API
- You're building a SaaS, portal, or content-driven product
- Convention-over-configuration and a large ecosystem matter most
- Raw async throughput is not the dominant constraint
Choose Flask when…
- You have a small, simple service with minimal dependencies
- You want maximum freedom over structure and libraries
- Async and built-in validation are not requirements
- You are maintaining an existing Flask codebase, not starting fresh
Need a full Django web app rather than a standalone API? See Django Development for Canadian Teams, or broader Python work: Python Development Services.
Best Fit For
- Canadian SaaS, proptech, and AI teams that need high-throughput, auditable Python APIs
- products integrating Stripe billing, enterprise SSO, LLM providers, or provincial health systems
- teams serving Quebec users who need bilingual EN/FR APIs and automated-decision logging
- migrations from slow Flask or Django REST APIs to modern async FastAPI
Not the Right Fit When
- simple CRUD admin tools where a full async API offers no real benefit
- engagements looking only for staff augmentation without delivery ownership
- pure frontend or marketing-site work with no API or backend complexity
- teams wanting an API rewrite with no measurable performance or scaling problem to solve
Need broader Python work beyond APIs? See Python Development Services, or serving AI features inside your product, see AI Feature Development.
Our FastAPI & Python Stack
Modern async technologies and proven patterns, deployed to AWS ca-central-1 (Montreal) for Canadian data residency
Core Framework
Data & Storage
DevOps & Cloud
How to Get Started as a Canadian Team
We recommend starting with an API Discovery Sprint: clarify the workload and architecture before committing to a full build. All engagements billed in CAD via Stripe.
API Discovery Sprint
Recommended start
Clarify the workload, data contracts, throughput targets, and architecture before committing to a full build. Billed in CAD via Stripe, delivered with daily async updates and a fixed estimate at the end.
- Workload and throughput analysis
- API and schema design
- Architecture and scaling plan
- Migration assessment if relevant
API Build Sprint
Ship a production-ready FastAPI service or set of microservices with async foundations that are genuinely ready to scale, not a throwaway prototype.
- Production-ready async API
- Pydantic models and OpenAPI docs
- Clear deliverables and timeline
Maintenance & Retainer
Ongoing FastAPI maintenance, performance tuning, and feature work end-to-end.
- Security and dependency upkeep
- Performance and scaling work
- Retainer or time-and-material
Selected Work
FastAPI services and API products we have built and shipped, each linked to its case study.
DiscoveredBy
AI search visibility platform that tracks how brands appear in ChatGPT, Gemini, Perplexity, Claude, and Grok, built with FastAPI, SvelteKit, and AI agents.
Read case studyOnlineCompiler.io
Sandboxed code execution platform for 12 languages with a REST API, WebSocket support, an embeddable widget, and MCP support for AI agents.
Read case studyIntentport
Our voice and text AI agent for websites: answers from live business data, books appointments, and sends qualified leads to the CRM in five languages.
Read case study
CREDITABLE
Employee financial wellness platform covering savings, workplace loans, and repayment workflows, built on Django and FastAPI.
Read case studyFastAPI Development FAQs for Canadian Teams
Straight answers to what Canadian founders and CTOs ask us before starting a FastAPI project.
What drives the cost of a FastAPI project?
The main drivers are scope and endpoint count, the complexity of your data model, how many third-party services you integrate (payment, identity, and LLM providers, accounting platforms), whether the API must be fully bilingual, whether you need real-time or streaming features, and the privacy evidence your buyers expect. We give a fixed estimate in CAD after a short discovery sprint rather than running an open-ended hourly meter.
How do you handle French-language and bilingual API requirements?
We treat French as a first-class locale, not a translation layer added at the end. APIs negotiate language through Accept-Language, Pydantic models carry per-locale fields, error messages and notifications exist in both languages, and search handles accents correctly. If you serve Quebec, French matters for consumer-facing content, so we plan bilingual scope into discovery.
Is FastAPI fast enough compared to Node.js or Go?
For most API workloads, yes. FastAPI runs on async Starlette and Uvicorn and delivers throughput in the same class as Node.js and close to Go for typical I/O-bound APIs, while keeping Python’s ecosystem for data and AI. Go still wins for extreme CPU-bound or ultra-low-latency cases, but for AI service layers, data-heavy APIs, and most SaaS and data backends, FastAPI is fast enough and far quicker to build.
Why is FastAPI the standard for AI and LLM backends?
FastAPI is async by design, so it handles the long-lived, concurrent connections that LLM calls and streaming responses require, and it sits in Python, the native language of AI tooling like LangChain, vector databases, and model SDKs. That makes it the natural place to build RAG endpoints, model-serving APIs, streaming chat, and agent backends without a separate stack.
Can you migrate our Flask or Django REST API to FastAPI?
Yes. We audit the existing API, identify async and performance bottlenecks, and migrate to FastAPI incrementally, running services side by side and cutting over endpoints without downtime, rather than risking a big-bang rewrite that destabilises the product your Canadian customers rely on. Many engagements start as a migration and performance audit sprint.
Where will our API and data be hosted?
For Canadian products we usually deploy to AWS ca-central-1 (Montreal), multi-AZ, with ca-west-1 (Calgary) available as a second Canadian region for disaster recovery. Personal data, backups, and logs stay in Canada, which simplifies privacy and health-partner reviews. We also document every service outside Canada an endpoint calls, including LLM providers, since that is where residency promises usually break. Privacy is considered from the first architecture session.
How does billing work for Canadian teams?
We invoice in CAD and collect via Stripe, with engagements structured around fixed-scope sprints or a monthly retainer.
Do we own the source code and IP?
Yes. You own all source code and intellectual property we produce for you. Everything is committed to your repositories as we build, so there is no lock-in and no handover risk if you later bring the work in-house or move to another team.
Ready to Build a Fast, Reliable API?
If you need a team to build or scale FastAPI services, with CAD billing, privacy-aware delivery, and AWS ca-central-1 (Montreal) data residency, we are ready to talk. No junior handoffs, no ticket mills. Just high-performance API engineering for Canadian teams.