Modern Monoliths–The race back to the future starts now

I started my IT career in the early 90s when I was still in university. My first commercial profitable software product was a simple POS and inventory management system I put together using Foxbase, for a small clothing shop I worked at as a night guard. It took a few days to make it work and it did what it intended to do. Every time something broke or the shop owners wanted to make any changes I had to come in and help. My early lesson in job security and vendor lock-in! Eventually the shop gave up on the idea of automation and switched back to the manual process, until it was closed by the authorities for some unrelated reason. And I moved on to intern at one of the leading international banks.

At a time, the Soviet Union collapsed and the whole country rapidly transitioned from centrally planned to market economy. The pace of change was unprecedented, especially in the financial and banking sectors, where the old economic model was being replaced, in a matter of months, with a patchwork of ad-hoc regulations, conflicting and inconsistent reporting requirements, and lack of any sense of direction. The bank I worked at operated on a mainframe and then on AS400 based core banking system, heavily customized to fit the local requirements. It was a great lesson in developing adaptive IT systems that could move fast, be ready to pivot on a moment’s notice, and help companies compete and strive in an unpredictable environment. It was also my first introduction to monolithic systems of record that encapsulate various aspects of company operations, running on a shared database, that we managed to keep aligned with constantly changing business demands.

Fast forward 30+ years later. The cell phones we carry in our pockets are orders of magnitude more powerful than the mainframe or AS400 systems we started with back in 80s and 90s. Yet in my chats with peers and customers, I often sense a familiar anxiety due to lack of control, uncomfortably fast pace of change, the realignments of the market, and the “unique” IT challenges of keeping pace while operating on limited budgets and capacity. Nothing is new under the sun indeed.

After the hype of microservices in early 2000s transitioned to fully productionalized and mature solutions, companies re-consider the promised benefits of decentralized IT landscapes consisting of hundreds or thousands of specialized services, each operating on their own platform. The real-world combined velocity and adaptability in many cases is comparable or even lower than legacy platforms, all at a significant price premium. The technology leaders are pivoting back toward monolithic architectures. This shift signals a pragmatic return, acknowledging the hidden costs, complexity, and operational overhead the microservices often entail. In this context, legacy platforms like IBM i emerge as the underdogs that often win the race back to simplicity, efficiency, and reliability.

What are the main characteristics of Modern Monoliths? At high level, the latest monolithic architectures are highly cohesive systems that address multiple critical business processes end to end, while sharing the same code repository and database, and emphasizing the modular design, separation of concerns, and clearly defined domain boundaries. Various components are independent enough to evolve at a different pace yet consolidated enough to reduce operational and especially integration complexities. Recognizing that no single system is an island, the modern monoliths offer well defined APIs and data flows for integrating with other operational and analytical systems, customers, partners, and communities. Simplicity and maximized reuse, at a fraction of the cost of typical distributed apps, teams, and processes.

Of course nothing comes free in this world, and there are several risks and considerations when developing efficient modern monolith architecture and strategy. The top concerns we hear from the business leaders are lack of qualified workforce, outdated user experience, complex interdependencies slowing down the speed of change and feature delivery, and, last but not least, limited integration options for accessing data and business logic. The companies rolling out the Modern Monolith platforms must address these concerns head-on!

This vision gradually became a Polestar guiding our team’s legacy modernization delivery. With ever increasing pace of change and market disruptions, the time for re-evaluating the architectural foundation is now. IBM i and mainframe systems, with proven strengths in security, reliability, and low TCO, emerge as strategic differentiators. We pulled it off back in 90s, adopting an AS400-based core banking system to rapidly changing markets, and I am convinced customers that execute on the Modern Monolith strategy have a unique competitive edge, and use it as a thrust forward, or at a minimum as a life raft in a turbulent market.