Vacature
Python / Django Developer
Fulltime
WO
Other
Hybride
Direct beschikbaar
About Swishfund Swishfund is a fast-growing FinTech scale-up that offers entrepreneurs an attractive alternative to short- and medium-term business financing through its online platform. Technological innovation and AI are key pillars in this mission. Swishfund makes business loans simple, flexible, and fast, so entrepreneurs can stay focused on what matters most their own business. We’re a small team with a big platform, which means your code doesn’t disappear into a corporate void it ships, it matters, and real entrepreneurs rely on it. We combine the speed and tech-mindedness of a fintech with the regulatory rigour of a licensed financial institution. Think startup energy, but with actual compliance. Yes, those two things can coexist.
About the Role
We are looking for an experienced Python/Django developer to maintain and improve Calmstone, our core lending and loan administration platform. Be open, flexible and eager to learn.
Calmstone powers the full loan lifecycle across the Netherlands and the United Kingdom — from application intake and credit assessment through contract generation, digital signing, payment collection, and ongoing loan servicing. You will work on a production system that integrates with banking APIs, credit bureaus, and CRM platforms, handling real financial data and regulatory requirements.
The Platform
Calmstone uses server-side rendering with Django templates, jQuery, and Bootstrap for the frontend, and connects to MySQL databases (including a Snowflake data warehouse for analytics).
What You Will Do
- Maintain, and improve the existing Django codebase across all apps, ensuring stability and reliability of the production platform
- Build new features and modules to support business growth, including expansion into additional market
- Improve code quality through refactoring — for example, migrating legacy JSON-based data structures to proper Django.
- Write and maintain tests to increase coverage and confidence in deployments
- Optimise database queries and application performance across the multi-database architecture (MySQL, Snowflake)
- Contribute to the CI/CD pipeline and Docker-based deployment infrastructure on AWS Requirement.
Must Have
- 3+ years of professional experience with Python and Django in a production environment
- Strong understanding of relational databases, particularly MySQL, including query optimisation and migrations
- Experience working with RESTful APIs — both building and consuming them
- Familiarity with Docker and containerised deployment workflows
- Experience with Git and CI/CD pipelines (GitLab CI preferred)
- Comfortable reading and working with a large existing codebase
Nice to Have
- Experience with payment processing systems or banking API integrations (SEPA, direct debits)
- Familiarity with credit bureau data and scoring models
- Knowledge of Django REST Framework (DRF) and API documentation tools (Swagger/OpenAPI)
- Experience with Redis, Celery, or django-background-tasks for async job processing
- Frontend skills: jQuery, Bootstrap, D3.js, or willingness to work with legacy frontend code
- Experience with AWS services (S3, EC2, ECR) and infrastructure management
- Familiarity with Prometheus/Grafana for monitoring and observability
- Knowledge of data analysis tools: pandas, NumPy, scikit-learn
- Dutch language skills are a plus but not required
What We Offer
- A meaningful role working on a production financial platform with real impact
- Ownership and autonomy over the technical direction of the application
- Flexible working arrangements (hybrid within the Netherlands)
- A collaborative team environment with room to grow
- Competitive salary based on experience
Interested?
Send your CV and a brief motivation to our hiring team. We look forward to hearing from you.
