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Hottest information about 4th Annual Retail Banking Technologies Summit



Chief Enterprise Architect
Danske Bank

The Big Ball of Mud (BBoM) by Craig Hughes

No matter how well a system was designed, through no fault of its own or of those enhancing it, it eventually evolves into a Spaghetti Architecture often termed the Big Ball of Mud (BBoM). These systems show clear signs of unregulated growth and repeated expedient repair. Information is shared promiscuously amongst different elements of the system, often to the point where nearly all the important information becomes global or duplicated. Even systems with well-defined architectures are prone to structural erosion. The relentless onslaught of changing requirements that any successful system attracts can gradually undermine its structure. Systems that were once tidy become overgrown as piecemeal growth gradually allows elements of the system to sprawl in an uncontrolled fashion.

These systems were not intentionally designed this way. So, what are some of the forces that drive good developers to build such ugly solutions?


New business requirements, regulatory changes and enhancements; there is always something, but all that is required is either not ready or not available. We often try to avoid this problem by making tactical solutions to meet the immediate need. This resulted in quick-and-dirty code that was intended to only be used once and then discarded. However, such code often takes on a life of its own. Despite casual structure and poor or non-existent documentation, it works, so why fix it? When a related problem arises, the quickest way to address it might be to modify this working code, rather than design a proper solution, from the ground up.

Budget decisions, time constraints, management pressures and outside influences are often the pressures that lead to this behaviour.

Focus on Functionality in Silos

All too often, Conway’s law or the “the mirroring hypothesis” finds its way into an organisation. This creates silos within the business which are mimicked in IT and systems. Functionality gets produced by the silo, for the silo, with no consideration of other areas. Often leading to much bespoke code for specific use-cases on shared process and masses of redundant and duplicate code over time. A strong example of silos includes channels; mobile, internet banking, branch systems, etc.

Unclear Data ownership

Following on from silo-focused development is unclear data ownership. Silos develop systems managing data across multiple domains, often producing data for a specific domain managed by multiple silos. Ownership of this data sector becomes a challenge – especially when we want to manage it centrally or create a single view of the data.

I’ll be at the 4th Annual Retail Banking Technologies Summit, 4-6 February 2020 in Vienna, presenting Danske Bank’s case study on how we are addressing this problem. This, while preparing for Open Banking – without creating another layer on top of our BBoM.

Craig Hughes a specialist in API and web technologies employed by Danske Bank as Chief Enterprise Architect, with a strong focus on APIs (internal and open banking). Currently responsible for breaking the core banking systems into business domains. Using these as the building blocks to create reusable business process via APIs. Employing an evolutionary architecture to move ahead strategically, while still supporting the day-to-day operations and growth of the business.
An experienced enterprise architect, solutions architect and development manager with over 20 years of hands-on technical and management experience. A logical thinker with a proven track record managing and growing multiple distributed agile development teams (local and international; India, UK, New Zealand) in the financial services sector.
Demonstrated, designed and delivered event-driven architectures; reducing channel driven inquiry traffic loads from core systems. Implemented blockchain technology (Ripple) for cross-jurisdiction payments and near-time remittance to India (via India’s Unified Payments Interface). Accomplished the delivery of external API’s to facilitate B2B interaction.

28 NOVEMBER 2019


Director of Sales & Distributional Channels

3 Questions For Tomas Reytt

How does your bank face the current challenges in mobile banking?

We believe that mobile banking has even greater potential than internet banking. This is mainly based on how much time people spend with their mobile phones today and that they have mobile with them everywhere and at any time (as opposed to internet banking, which was mostly realised from a PC). So the customer has the “bank” all the time accessible and the challenge for us is to make sure we are extremely simple, with simple and convenient UX/UI and not to be on the top list of applications the customer uses.

How can improvement of the mobile banking lower the costs of your bank?

In general, this might be definitely a way for some banks. Unfortunately, not in our case, because we, from early beginning, build mBank’s sales-service model on “digital” principles. Previously it was Internet banking, nowadays, mobile banking. Big opportunity I see primarily in traditional banks with wide branch network structure.

What is the future potential of open banking?

Potential is definitely there, the question is when it should be fully utilised, it means from time perspective. So far, from customer perspective, open banking is something where majority of population doesn’t see big advantage and has rather negative approach (primarily due to fear of data misuse). As soon as the customers start to understand the benefits and believe in the security of this service, then adopting will become automatic and the potential could start to be fully utilised.

Tomas Reytt is Director of Sales & Distributional channels in mBank CZ/SK responsible for development of all channels including both digital and physical and introducing new initiatives & projects to provide innovation and disruptive solutions to the market, create seamless experience in digital channels, and build a strong relationship with customers. Tomas has more than 17 years experiences in strategy and transformation, product and segment business in Retail and MSE, pricing and life-cycle management, process management (Lean, Sigma and Kaizen) and business development in the financial industry. Prior to joining mBank he has worked more than 4 years for PwC (PricewaterhouseCoopers) as Manager in Financial Services Management Consulting practice and for Česká spořitelna (TOP 3 Czech bank, part of Erste Group) where he was responsible more than 11 years for management of product and segment business in Retail and MSE, process management and optimisation through Lean Six Sigma and Kaizen, bank‘s performance improvements, product, segment & sales channel strategy. Tomas holds Master’s degree with double major – MBA at The Nottingham Trent University and Prague Schools of Economics, is 6 Sigma – Green & Black Belt. Tomas is fluent in English, Czech and have basic knowledge of German and Russian.

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