Why Modular Monoliths Don't Solve Core Issues

TL;DR

Modular monoliths often fail to address deep-rooted human and cultural challenges within large Rails applications. While they promise better structure, the real issues stem from organizational culture and practices. To truly enhance engineering processes and alleviate operational problems, companies must focus on improving developer education, collaboration, and prioritizing code quality over mere architectural changes.

Transcript

hi everyone uh I'd ask if you can hear me but I can hear myself pretty well so I think the sound is good who got woken up by the fire alarm at 2:30 a.m. wo who got stuck in an elevator and had a panic attack uh thank you to the strangers and my friends who were in the elevator with me who uh talked me off a ledge and then figured out how to... Read More

Key Insights

• Modular monoliths promise better structure but often introduce new challenges and unmet goals, revealing deeper human and cultural issues.
• Architectural, operational, and organizational problems in Rails applications are often human problems, not technical ones, requiring cultural solutions.
• Modularization doesn't inherently improve code organization or reduce coupling; it requires understanding software design and Rails conventions.
• Operational issues like flaky tests and slow CI are not solved by modularization but by addressing technical debt and improving engineering practices.
• Assigning code ownership in modular monoliths can be challenging, as it doesn't guarantee accountability or prioritization of maintenance tasks.
• Modularization can lead to undesirable patterns like primitive obsession and ownership obsession, affecting code quality and collaboration.
• Effective modularization should focus on functional isolation rather than domain isolation to avoid unnecessary complexity and inefficiencies.
• Improving engineering culture through education, indoctrination, and collaboration is crucial for addressing underlying problems in large applications.

Questions & Answers

Q: What are the main challenges faced by growing Rails applications?

Growing Rails applications face architectural, operational, and organizational challenges. Architectural issues include poor code organization and tight coupling, operational challenges involve flaky tests and slow CI, and organizational problems relate to code ownership and onboarding complexities. These challenges are often human problems, not technical ones, requiring cultural solutions.

Q: Why do companies consider modular monoliths as a solution?

Companies consider modular monoliths as they promise the best of both worlds—maintaining the ease of a monolith while introducing modularity to manage complexity. The goal is to improve code organization and reduce coupling without the overhead of microservices. However, these benefits are often not realized due to underlying human and cultural issues.

Q: What are some negative consequences of modularization?

Negative consequences of modularization include primitive obsession, where developers avoid dependencies by passing IDs instead of objects, leading to performance issues. Ownership obsession can create silos, reducing collaboration. Excessive packaging can result in a fractured codebase, and code duplication becomes a problem as developers try to avoid dependency violations.

Q: How does modularization fail to address operational issues?

Modularization doesn't inherently fix operational issues like flaky tests and slow CI because these problems are often due to technical debt, not architecture. Flaky tests can be caused by network calls or resource contention, while slow CI may result from inefficient queries or large test suites, requiring targeted solutions rather than architectural changes.

Q: What role does education play in solving these challenges?

Education is crucial in solving these challenges as it equips developers with the knowledge to write idiomatic Rails code and understand software design principles. Without proper training, developers may fail to utilize Rails effectively, leading to poor code quality and structural issues. Education helps address human problems by fostering a better engineering culture.

Q: What is the importance of engineering culture in addressing these issues?

Engineering culture is vital for addressing these issues as it influences how problems are prioritized and solved. A culture that values code quality, rewards maintenance work, and fosters collaboration can prevent the accumulation of technical debt and improve overall productivity. Shifting focus from shipping features to maintaining quality is essential for long-term success.

Q: How can organizations improve their approach to modularization?

Organizations can improve their approach to modularization by focusing on functional isolation rather than domain isolation, starting with fewer packages to avoid complexity, and ensuring that modularization aligns with solving actual problems rather than creating new ones. It's important to address technical debt and maintain a healthy engineering culture that supports these efforts.

Q: What is the myth of the modular monolith according to Uchitelle?

According to Uchitelle, the myth of the modular monolith is the belief that architectural changes can solve human and cultural problems. While modularization may offer some technical benefits, it cannot address deeper issues rooted in organizational culture, such as prioritizing code quality and fostering collaboration. These problems require cultural solutions, not architectural ones.

Summary & Key Takeaways

• Eileen Uchitelle argues that modular monoliths, while appealing, fail to solve underlying human and cultural challenges in large Rails applications. She emphasizes that these issues are not technical but rooted in organizational culture, requiring a shift in engineering practices and priorities.

• The talk highlights the limitations of modularization, noting that it doesn't automatically improve code organization or reduce coupling. Uchitelle stresses the importance of understanding software design and Rails conventions to address these issues effectively.

• Uchitelle calls for a focus on improving engineering culture through better education, indoctrination, and collaboration. She argues that addressing these human and cultural problems is key to solving architectural, operational, and organizational challenges in large Rails applications.