Nearshore Fintech Development for a Leading European Online Bank

Client Overview

Our client is a leading European online bank headquartered in France, offering a full range of retail banking products – from retail banking accounts and savings to mortgages, insurance, and investment services. The bank has grown from a digital start-up to a platform serving over 9 million active clients. Keeping their CRM platform fast, secure, and compliant across multiple regulatory environments is an ongoing engineering challenge – and the core of our work together.

When the partnership began in 2007, the brief was straightforward: they needed a dedicated IT services team to help build and maintain a CRM for a growing French online bank. But as the bank grew, so did the scope of what it needed from us. Over nearly two decades, we have encountered and worked through several main challenges:

• Expanding into Germany and the UK required full software internationalisation and regulatory adaptation. 

• A growing product catalogue – mortgages, card payments, insurance – eventually exposed the limits of a monolithic architecture. 

• Delivery cycles of three months became too slow for a bank moving at digital speed. 

• Keeping aging technology current is an ongoing challenge, especially in a regulated industry where outdated software means known security vulnerabilities. 

Each of these was a problem we identified and solved together – often before it became critical.

A dedicated, full-stack nearshore team 

Proxiad SEE started with three nearshore developers in 2007. Today, the team consists of 25 developers, 10 technical project managers, 8 QA and test automation engineers, and 2 business analysts. Every role was added at a moment the partnership genuinely needed it – QAs became an integral part of the team in 2009, and BAs were introduced to the local team in 2021 to bring requirements-gathering in-house and cut turnaround time.

Earning the right to own delivery: the move to fixed price 

In 2013, the client moved from a dedicated team model to a fixed price engagement – placing full responsibility for budget, timeline, and quality with Proxiad SEE. It is a model that only works when trust has been earned over time. To make it work, we introduced the Technical Project Manager role: engineers with strong development backgrounds who own the full delivery process end to end, without the client needing to manage the details. Within the technical PMs, there are two roles that oversee the whole team – a technical project director and a functional project director.

Microservices migration that cut delivery times by 12x

In 2018, the team redesigned the bank’s architecture from the ground up – replacing the monolith with self-contained, function-specific applications built from scratch. Delivery cycles dropped from three months to one week. In 2020, our team had developed 14 applications: as of 2026, their number has grown to 20, with more on the way. The same initiative also included a full data platform migration, generating meaningful savings in infrastructure and licensing costs.

Continuous tech stack modernization for security and scalability

In a regulated industry such as finance, running on outdated software is not an option. The team actively manages the full technology stack – both front-end and back-end – keeping it current with each major release. In 2025 alone, around 1,000 man-days went into migrating to Java 21 – driven by security compliance and scalability requirements. Non-regression testing, increasingly automated, runs across all applications to protect quality through every change.

SLAs designed by us, adopted by the client

Proxiad SEE developed and introduced a structured SLA framework to govern response times and issue resolution across all applications. The client adopted it, and we have met it consistently ever since – not by reacting to problems, but by designing preventive measures that stop most issues before they happen.

Proxiad SEE has supported us for more than 19 years in the construction and evolution of our middle office information system, built around a CRM.

Thanks to their highly technically and functionally competent, but also sustainable team, Proxiad SEE contributed to the growth of BoursoBank, making with us the necessary transformations and adaptations to automate the bank’s management processes and support our 9 million customers, while evolving the technical layers to always be state of the art.

Isabelle Nurit, IT Engineering Manager at BoursoBank

Results

• 12x faster delivery cycle, reduced from 3 months to 1 week after the 2018 microservices migration. 
• 9 million active clients supported – up from under 1 million when the partnership began. 
• 20+ applications developed and maintained in production. 
• ~1,000 man-days invested in Java modernization in 2025 alone. 
• Significant cost savings from migrating Oracle databases to PostgreSQL across the full application environment. 
• Consistent SLA compliance through proactive, team-designed preventive measures. 

Quarterly steering committees and annual strategic reviews keep both sides aligned. Teams visit each other in person every year. Client communication is open and shared across the full nearshore team – not filtered through a single point of contact. That transparency, combined with technical depth and a genuine sense of ownership, is what has kept this partnership going for almost 20 years.

“What makes this partnership work is that the team genuinely owns what they deliver. The move to a fixed price model was only possible because we had built up that level of trust in us over the years.” – Svetozar Stoyanov, Service Center Head, Proxiad SEE