CASE STUDY · FinTech & production delivery

Take an existing financial platform from unfinished work to controlled delivery.

Backend completion, recurring billing, secure access and automated trading-account provisioning for a subscription-based FinTech platform.

Discuss your platform’s next release

Technical ownership: Itzhak Shaul · Architecture & hands-on development
Engagement: Selected freelance project · Client identity confidential
Core technologies: FastAPI · Django · PostgreSQL · Redis / Celery · Docker · Tranzila · PyTest

An almost-finished platform can still be far from a dependable release. This engagement focused on completing an existing FinTech codebase while treating payments, access and account provisioning as business-critical workflows.

A strong fit for: Founders and product teams with an existing subscription or financial platform that needs completion, technical cleanup or release hardening.

The business challenge

An existing platform needed development completed and technical debt addressed without breaking live components. Payments, subscriptions and account provisioning required deliberate handling of retries, permissions and background work.

My responsibility

I joined as architect and developer, reviewed the existing FastAPI backend, completed development and established staging and production configurations with automated delivery and tests.

How the system fits together

Simplified workflow illustrating the delivered capabilities.

Subscription
Payment webhook
Validated background job
Trading account

What I built

Backend remediation

Identified slow queries and N+1 patterns, added Pydantic type definitions and separated development, staging and production configuration.

Recurring payments

Tranzila tokenization, recurring billing and payment webhooks with idempotency for financial transactions.

Secure subscription access

JWT authentication with 2FA, role-based access and subscription lifecycle management.

Automated provisioning

MetaTrader MT4 / MT5 account creation through the Manager API, Celery background jobs and PyTest unit and integration tests with mocks.

ARCHITECTURE & IMPLEMENTATION

The technology, and the work behind it.

How the documented stack supports the business workflow, from the application layer to integrations and operational controls.

Backend review and completion

Python · FastAPI · Pydantic · Django admin

The work began inside the existing backend: reviewing code, identifying slow queries and N+1 patterns, adding type definitions with Pydantic and reducing technical debt. Existing live components had to remain functional as development progressed.

Environment and deployment boundaries

Docker Compose · Nginx · CI/CD · PostgreSQL

Development, staging and production configuration were separated. The deployment stack combines the application, Django administration, PostgreSQL, Redis / Celery and Nginx, providing a controlled place to review changes before release.

Authentication and subscriptions

JWT · Two-factor authentication · Role-based access

Authentication, permissions and subscription lifecycle management connect product access to the right user and account state. These controls are part of the platform’s operating behavior, not an isolated login screen.

Financial transactions

Tranzila · Tokenization · Recurring billing · Webhooks

Payment integration handles tokenized billing and asynchronous webhook events. Idempotency protects financial operations from being repeated when an event or request is processed again.

Provisioning and verification

MetaTrader MT4 / MT5 Manager API · Celery · Redis · PyTest

Trading-account provisioning is automated through the Manager API and background jobs. Unit and integration tests with mocks provide checks around behavior without treating test calls as real financial or trading actions.

Follow the workflow

An illustrative walkthrough of the capabilities described in this project.

Subscription and payment events enter a workflow that checks account state and processes financial transactions with idempotency.
Background jobs handle automatic MT4 / MT5 account provisioning through the Manager API.
Environment separation and automated tests support review of the changes around these critical integrations.

The engineering behind the result

In a financial workflow, a retry must not become a second financial action. Idempotency, testable integration boundaries and environment separation were central to the work.

What this enables

The delivered capabilities connect subscription status, billing and account provisioning, supported by clearer deployment boundaries and automated checks around critical behavior.

BUILD A SYSTEM AROUND YOUR BUSINESS

Your workflow could be the next case study.

If development has stalled, a rewrite is not automatically the answer. I can join the codebase, identify the release blockers and work through them with attention to the systems already in use. You get a senior architect who also does the implementation.

Send the current platform scope, known release blockers and the payment or provisioning integrations involved. We can start with a focused review and an agreed completion milestone.

Work directly with Itzhak Shaul, founder of Methodspire and Principal Software Architect with 30+ years of hands-on experience. Start with a focused conversation about the workflow, constraints and delivery scope.

Selected freelance experience of Itzhak Shaul. Project details are summarized to protect client confidentiality.