Reliability lives beneath the interface.

A timeline editor looks like clips and controls, but underneath it coordinates media import, playback, time conversion, project state, undo history, synchronization, rendering, and export. These systems must agree about the state of the project at every point in time.

That makes architecture visible in everyday interaction. A drag operation that updates the screen but not the model feels broken. A preview that drifts out of sync undermines trust. An export that differs from the timeline breaks the user’s expectation of what the project means.

Make state-changing actions explicit.

A command model can define each action’s inputs, preconditions, result, failure behavior, and relationship to undo and redo. The interface expresses intent; the core owns the authoritative state transition.

No architecture pattern solves every problem. A command bus can add indirection; native boundaries introduce serialization and concurrency concerns; GPU pipelines add synchronization and resource-lifetime challenges. Each mechanism should justify itself by making behavior easier to reason about or test.

Test the edge cases that break trust.

Useful test cases include missing assets, invalid time values, canceled commands, undo after repeated edits, project recovery, and export metadata. The target is predictable behavior even when the environment is imperfect.

FluxCut explores these boundaries. The ambition is a coherent editing experience; the work is to make each layer dependable before other layers rely on it.