System Architecture

Comparing Level 1 and Level 2

Level 1

Level 2

Description

At Level 1, you're not yet responsible for system design, but you're starting to understand how the parts fit together. Your focus is on building features within an existing architecture and following established patterns. You're learning to read diagrams, understand service boundaries, and follow conventions that others have set. You may not yet make architectural decisions, but you're becoming aware of them—and that's the first step.

Description

At Level 2, your focus shifts to reinforcing and extending the architecture that already exists. You make implementation decisions with the system's structure in mind and help ensure new code aligns with architectural intent. You work within the current architecture to make it more robust, resilient, and consistent. You may raise small architectural concerns or suggest refinements, but you aren't yet expected to design new components from scratch.

Key Behaviors

  • •
    Builds features within the boundaries of existing systems
  • •
    Follows architectural guidance and codebase conventions
  • •
    Asks questions about how systems are structured
  • •
    Starts to understand the purpose of components like APIs, databases, and services
  • •
    Learns from code reviews that touch architectural concerns

Key Behaviors

  • •
    Deepens understanding of the system's patterns and constraints
  • •
    Implements features in ways that improve system reliability and clarity
  • •
    Identifies inconsistencies, edge cases, or architectural drift in existing systems
  • •
    Strengthens boundaries between components by clarifying ownership and interfaces
  • •
    Follows and enforces architectural conventions in code reviews

Common Struggles

  • May not recognize when they're introducing architectural risk
  • Focuses only on local code, not system-wide behavior
  • Struggles to reason about how their changes affect other parts of the system

Common Struggles

  • May patch around weak design instead of escalating concerns
  • Might lack confidence to raise architectural issues with senior engineers
  • Can struggle to balance delivery speed with system clarity

Success Indicators

  • Understand the basic architecture of the systems you work on
  • Respect system boundaries and follow established patterns
  • Ask thoughtful questions about design decisions
  • Build with awareness of how your work fits into the bigger picture

Success Indicators

  • Understand not just how the system works, but why it's structured that way
  • Make the architecture stronger and more coherent through your day-to-day work
  • Spot inconsistencies and raise architectural questions early
  • Encourage others to build with structural integrity in mind

Mindset Shift

From:

"I build my part."

To:

"I understand how my part fits into the system."

Mindset Shift

From:

"I keep the system healthy."

To:

"I shape the system so it stays healthy as it grows."

Questions to Ask Yourself

  • How do requests flow through this system?
  • What assumptions does this component make about others?
  • What breaks if this service fails?

Questions to Ask Yourself

  • Are we relying on brittle assumptions or implicit contracts?
  • Where is complexity growing faster than our structure can support?
  • What can I simplify or modularize without changing system behavior?

Build These Habits

  • 1
    Read architecture docs and ask questions about them
  • 2
    Trace how a request moves through the system from end to end
  • 3
    Pay attention to how other teams structure and integrate their work

Build These Habits

  • 1
    Review small refactors and their long-term architectural impact
  • 2
    Document recurring pain points or design flaws you notice
  • 3
    Help newer engineers understand how to work within the architecture

Seek Feedback

  • "Does this approach follow the architecture we've defined?"
  • "Could this change have unintended effects on other parts of the system?"
  • "What tradeoffs were considered in choosing this design?"

Seek Feedback

  • "Is there a more resilient or simpler way to implement this?"
  • "Does this follow our architectural principles, or is it bending them?"
  • "What areas of the system feel fragile, and how might we strengthen them?"

Signals You're Ready to Level Up

  • You understand the high-level architecture of the systems you touch
  • You spot when something doesn't fit the design patterns in use
  • You talk about your work in terms of system impact

Signals You're Ready to Level Up

  • You improve architectural integrity through thoughtful implementation
  • You help others understand and follow system design principles
  • You raise and discuss issues that affect system-level clarity or stability

Focus Summary

  • Zoom out
  • Ask why
  • Learn how systems are shaped

At Level 1, you're developing architectural literacy. You build inside existing structures, ask smart questions, and start to see how everything connects.

Focus Summary

  • Support the structure
  • Spot the cracks
  • Build with care

At Level 2, you're not changing the architecture—you're fortifying it. You make it easier for others to build well, and you keep the system honest as it grows.