Guaranteed transactional integrity
ACID transactions over Django's ORM, locking and idempotency on every money operation. No duplicate request costs you a double charge or throws the balance out.
Backend development · Fintech
Backend development with Python for Fintech
We build your fintech backend with Python —Django for the financial domain, FastAPI for high-throughput APIs— with the transactional integrity and regulatory rigour the sector won't forgive.
THE CHALLENGE
The challenges of Fintech
Fintech software operates under constant regulatory and security pressure, where a failure carries direct financial and reputational cost. It needs regulatory rigour, traceability and an architecture that scales without compromising trust.
- Regulatory compliance (PSD2, PCI-DSS, GDPR)
- Financial data security
- Scalability under transaction spikes
- Integration with payment gateways and core banking
- Time-to-market without compromising rigour
How we help you
In fintech the backend is where the money actually moves, and there's no room for 'almost'. We build financial backends with Python: Django when the domain calls for a robust ORM, ACID transactions and a serious admin panel, and FastAPI when you need asynchronous APIs able to sustain thousands of requests per second without buckling. Guaranteed transactional integrity, security and compliance (PSD2, PCI-DSS, GDPR) from the very first commit, and observability to know what's happening with every operation in real time.
High-throughput async APIs with FastAPI
Async endpoints that sustain transaction spikes without degrading, with strict schema validation (Pydantic) and documented OpenAPI contracts for your integrators.
Security and compliance at the core
Encryption, secrets management, least privilege and traceability aligned with PSD2, PCI-DSS and GDPR. Auditing isn't a final patch: it's in the architecture.
Robust financial integrations
We connect gateways (Stripe, Adyen, Redsys), core banking, KYC/AML and open banking with resilient clients, retries with backoff and queued tasks (Celery) for what can't fail silently.
WHAT YOU GAIN
Backend development, results-driven
- Senior Python team that delivers value from the very first weeks
- APIs and microservices with Django and FastAPI, typed and documented
- Backend architecture designed to scale without rewrites
- Backend that's tested, observable and secure by design
- Full ownership of the code and the know-how
FAQ
Frequently asked questions
Why Python for a fintech backend?
Because it combines a mature ecosystem for financial domains (Django, ORM, ACID transactions) with FastAPI for high-performance async APIs. You get rigour where the data is critical and speed where throughput rules, without switching language.
How do you guarantee a transaction isn't processed twice?
With idempotency by design: idempotency keys, database-level locking and ACID transactions over Django's ORM. Every money operation is atomic, and retrying never generates a duplicate charge.
Can FastAPI handle high transaction loads?
Yes. FastAPI is asynchronous and, well designed with connection pooling, queues (Celery/Redis) and caching, it sustains thousands of requests per second. We load-test before production to size with data, not with assumptions.
Do you work in compliance with PSD2, PCI-DSS and GDPR?
Yes. Encryption in transit and at rest, secrets management, granular access control and tamper-proof audit logs. We prepare the backend for audits and certifications from day one, not when the regulator arrives.
Why Python for the backend instead of another language?
Python combines development speed, a mature ecosystem (Django, FastAPI, Celery) and a huge community, which means less time to production and a product that's easier to maintain and hire for. We choose the stack based on the problem, and for most APIs, data platforms and AI integrations, Python is the most solid option.
Django or FastAPI? Which one do you use?
It depends on the case. Django shines when you need a complete, batteries-included backend with an ORM and admin; FastAPI, when you want high-performance async APIs with strict typing. We often combine them. We recommend the one that fits your product, not the one that's trendy.
Can you step into an existing Python backend?
Yes. We audit the code, dependencies and architecture to understand its real state, and from there we stabilise, secure and evolve it without stopping your operation.
Shall we build something that scales, together?
Tell us about your project. We'll get back to you with a concrete plan and a senior team — not a generic quote.