In product development, achieving product market fit (PMF) is crucial, and a minimum viable product (MVP) serves as a key tool in this journey. It allows organizations of any size to quickly and inexpensively test a market hypothesis about a product’s core features, with minimal initial investment.

However, the technical and economic feasibility over time of an MVP relies heavily on its underlying structure, which is why successful engineering teams implement a minimum viable architecture (MVA). 

An MVA is the simplest design of a system's architecture that supports the core functionalities of an MVP while (a) allowing for future scalability and adaptability, (b) preventing potential user disillusionment due to performance issues, and (c) safeguarding against competitors.

Leveraging an MVA reduces the accumulation of architectural technical debt – the technical debt that results from the decisions made during the system design process regarding the architectural style, tech stack, development methodologies, etc. This is often costlier and more complex to resolve than code-level debt and can obstruct innovation initiatives, stifling the organization's growth and competitive edge. 

However, building “just enough architecture” to assess the technical viability of a product without slowing down the PMF evaluation can be very challenging. Engineering managers need to guide their teams to find the right balance when crafting an MVA to ensure quick market entry while also building a scalable and long-term solution that won’t be hampered in the future by its initial technological choices. 

Common mistakes in implementing minimum viable architectures

Implementing MVAs involves navigating common pitfalls that can significantly impact the effectiveness and sustainability of a product's technical foundation. Engineering leaders should look out for these mistakes:

Letting the architecture “emerge” 

Before the advent of agile practices, the prevailing approach was waterfall and big design up front (BDUF). However, in an effort to get away from documentation-driven and heavyweight software development processes, many of the agile guidelines were misinterpreted. 

This led many agile practitioners to believe that upfront design and architectural documentation are unnecessary because the architecture would “emerge” organically during the iterative and customer-focused agile development process.

However, this approach can lead to unplanned and inconsistent architectural decisions (e.g. patchwork of technologies and design patterns) as different teams iterate quickly without a unified architectural strategy or vision. 

Some degree of upfront architectural planning is essential to ensure team alignment and a coherent system design.

Tactical “prototype” minimum viable architectures

In an effort to deploy MVPs rapidly, some teams treat the MVA as a disposable prototype, resorting to building what's known as a "sacrificial architecture": a tactical, temporary solution expected to be reworked or replaced if the MVP succeeds.

Unfortunately, this approach can quickly become problematic, as these provisional solutions often turn permanent as a result of teams focusing on building new features, rather than addressing the accumulating technical debt. 

While this method has worked for a few companies like eBay, it has resulted in long-term challenges for others in terms of adaptability, performance, and maintainability.

Non-documented minimum viable architectures

Effective architectural documentation is essential for the success of any project, as it ensures the system is well understood and can be clearly communicated, boosting overall team productivity.

A frequent mistake is presenting architectural documentation with solely static system diagrams. However, effective documentation should also include detailed descriptions of requirements, decisions, constraints, trade-offs, etc. 

Creating a comprehensive record of all your technical system information allows teams to understand the rationale behind design choices made and make informed decisions on how to evolve the software. 

For example, knowing the initial assumptions about the maximum number of concurrent users at launch is crucial; it directly influences the scaling strategy teams adopt to manage growth and determines how they distribute the application across different servers or services. 

A well-documented architecture also highlights rejected options and the reasons behind these decisions, offering insight into the project’s constraints and helping manage technical debt. 

Neglecting this documentation can lead to reduced maintainability, increased complexity, and other long-term project viability issues.

Over-architected minimum viable architectures

Teams often over-engineer systems to solve hypothetical future problems that may never materialize. This typically occurs when software architects and engineers design systems based on worst-case scenarios informed by optimistic and speculative estimates from business stakeholders.

For instance, consider when a business predicts a high number of concurrent users. Engineers might add a safety margin to these estimates for extra security. This can then lead to a system designed to handle far more users than it will realistically encounter, incorporating unnecessary complexities like advanced caching mechanisms. Decisions like these result in overly complex systems that struggle to adapt, contributing to inefficiency and maintenance challenges.

Risks of neglecting MVAs

Neglecting the MVA while developing an MVP exposes the project to risks as the system scales. Ignoring essential technical requirements can lead to decreased user satisfaction when the architecture can't meet growing performance demands, resulting in user frustration and disengagement.

Moreover, poorly conceived architectures might require costly refactoring to meet performance, security, or scalability standards. This often leads to entrenched technical debt where quick fixes become permanent solutions and compound future maintenance and development costs.

A non-scalable or inflexible architecture also diminishes the product's ability to innovate or adapt, giving competitors a chance to surpass it with more refined solutions. After all, there are many examples in the tech industry where companies that thought they had the “first mover” competitive advantage – first to market with an innovative product or service– were later surpassed by fast-following competitors.

Balancing act: Speed vs system design

Engineering teams must select a strategy that strikes a delicate balance between rapidly bringing a product to market and building a scalable architecture that can adapt to future demands.

The MVA approach supports this by advocating for iterative development focused strictly on the known and essential requirements at each stage, avoiding the inclusion of unnecessary and unvalidated features.

In essence, creating an MVA involves building “just enough architecture” to evaluate the technical viability of a product, while keeping the design flexible enough to tackle future requirements. 

Effective ways to achieve this objective include: 

• Following the third principle of continuous architecture practice: “Delay design decisions until they are absolutely necessary.” By leveraging an iterative approach to system design, the team can correct suboptimal decisions and keep pace with technological and market changes.
• Contextualizing estimates: Base architectural decisions on realistic, time-specific user data to allow for adaptive evolution (e.g. How many concurrent users might be on the system within the first 6 months?)
• Use familiar technology: Choose well-understood technologies to speed up development, simplify enhancements, and improve productivity.

Final thoughts

There is always a tension between the MVP and its associated MVA: both will continuously evolve in small increments to meet additional requirements and while one might outpace the other at times, they will always be interconnected.

The importance of an MVA isn’t always fully understood by teams, and finding the right balance between focusing on the product vs. testing its technical viability can be challenging.

However, by adopting this practice and making upfront and flexible system design decisions, engineering leaders ensure that their teams can quickly create robust software systems that are viable for production.

This strategic approach ensures rapid market entry and maximizes return on investment by allowing architectures to evolve as needs change.