In the world of software, the label ‘mission-critical’ isn’t just a fancy moniker—it’s a non-negotiable contract of trust. These systems are the digital heartbeat of essential services; they simply cannot fail. Much like the intricate workings of a Swiss clock, every cog in a mission-critical system must mesh seamlessly to keep the hands moving precisely.

Characteristics of Mission-Critical Systems

Knowing that mission-critical systems are indispensable, we can then move on to what characterises them technically—they must be highly reliable, scalable, secure, and capable of adapting quickly. High reliability is achieved through built-in redundancy and self-healing mechanisms. Scalability is critical not only to handle peak demands without failure but also to scale down efficiently and avoid excessive costs for unused resources. The necessity for robust security is a given, and the same goes for adaptability; systems must rapidly adjust to new security threats and evolving business and consumer demands to stay effective and relevant.

Deciding how to build these systems to meet such needs is challenging. Every vendor will claim their solutions uniquely address your challenges, which leads to a significant decision: which vendor’s solution should you choose?

The Need for Vertical Integration

But before we answer that, the fact that you’re even facing this decision points to a fundamental issue: your system lacks inherent vertical integration.

Vertical integration is what businesses pursue when they aim to reduce dependence on external suppliers by producing more of the components that go into their products themselves.

Case Study: Apple vs. Microsoft

Consider the example of two well-known competing technology giants that adopted different strategies. Apple is vertically integrated, building its own hardware, operating system, and much of the application ecosystem that runs on top. Microsoft, however, has promoted an open standard, which has required Windows to be compatible with a variety of hardware from different manufacturers and to support a myriad of third-party software.

What’s the difference between them? Connect a new peripheral to each system, and you’ll experience it firsthand. While Windows has made strides in user-friendliness, I recall a time when, using the same Windows laptop for five years, reconnecting my mouse always prompted a notification that Windows was “searching for the driver.” Installing new printers often became a complex task of downloading the latest driver and hoping for compatibility. In contrast, ask any Mac user—they’ll tell you that when you plug in something new, it just works.

Why is this the case? Because Apple’s products are vertically integrated. From top to bottom, they orchestrate every aspect of their systems, crafting seamless user experiences that are strategically vital to their business—culminating in what many consider the perfect user experience.

This doesn’t mean that Microsoft’s approach is incorrect, unless, of course, your solution is mission-critical and you can’t afford the unexpected and unpredictable behavior that might emerge from the gaps between the layers of your solution.

Avoiding the Blame Game


The Blame Game

You’re likely familiar with the blame game that ensues when there’s a system failure. Yet, pinpointing fault is far less important to your customers than ensuring issues are fixed—or better yet, avoided altogether.

Embracing a Vertically Integrated Mindset

Even if your business isn’t fully vertically integrated (and its very unlikely that it is) this concept should still guide the design, build, and integration of your solutions.

Developing mission-critical software requires you to adopt the vertical integration mindset and skill set. You may outsource parts of the solution to trusted vendors, but understand that you are not outsourcing accountability. Their components should perform as promised, but ultimately, your customers won’t concern themselves with whether it was “your” software or a supplier’s that failed. They’ll see the system as a whole. So, it’s imperative to understand and mitigate risks across layers, components, and where necessary, between different vendors. Don’t fall into the trap of thinking, “It’s not my problem.” Recognise that if something fails, it may not be your fault—but it is always your responsibility.

You can manage this by rigorously applying key principles of systems integration and site reliability engineering (SRE). This involves thorough testing of all components, maintaining stringent quality control across the supply chain, and establishing clear lines of communication with all stakeholders involved. By doing so, you ensure that each piece of the puzzle not only fits but also performs reliably as part of the larger system, thereby upholding the trust placed in your mission-critical applications.

Our Commitment at SECTION6

At SECTION6, we specialise in building mission-critical software. Our team possesses deep skills and extensive experience across the entire technology stack. We integrate SRE principles and techniques into our practices and collaborate with clients using well-established Agile development methodologies. We also embrace DevOps principles and tooling to enhance development efficiency. With the aid of SRE, we systematically improve the reliability and resilience of the applications we build, ensuring that they are not only agile and adaptable but also secure and steadfast under pressure. Our aim is to deliver solutions that not only meet but exceed the rigorous demands of mission-critical operations.
Recognising the need for a vertical integration mindset in your mission-critical applications is a pivotal first step. The journey beyond that involves forging partnerships that understand and align with this philosophy. If you’re looking for expertise that can bridge the gaps and bring cohesion to every layer of your software infrastructure, SECTION6 is well equipped to guide you through this transformative process with our proven track record and dedicated team of professionals, not to mention our skills and experience in this area.

Embarking on this path with SECTION6 means investing in a partnership that’s committed to the long-term reliability and success of your mission-critical systems.


Perhaps it’s no wonder that Swiss trains are renowned for their reliability; they operate in sync with Swiss clocks, which exemplify precision and integration. This design, built and integrated from the ground up, inherently embeds reliability into the vertically integrated system.