Master. The top 2%. Institutional scale.
Flux-4 is the credential that signals institutional-scale capability. You replace a division. You operate with the strategic depth of a leadership team and the delivery speed of an engineering organization.
The credential that changes compensation conversations.
The Flux-4 problem is designed differently from lower tiers. It contains deliberately ambiguous constraints, competing stakeholder interests, and resource limitations that are not explicitly stated. Most candidates solve the problem as it is written. Flux-4 Masters solve the problem beneath the surface -- identifying what was not said, what cannot be done, and what must be decided first.
The 12-hour window tests endurance as much as capability. Flux-4 candidates who fail in the final hours typically do so because they front-loaded execution and ran out of strategic clarity when they needed it most. The pattern that works: spend the first 90 minutes on deep problem decomposition, build in parallel across all required deliverables, and reserve the final hour for narrative and strategic synthesis.
Flux-4 is the highest tier of the Flux Standard below Flux-5, and the highest at which the credential is awarded by rubric rather than by apex calibration. Passing it is a documented signal that the candidate operates at division scale.
A regional bank with $4B in assets, 12 branches, and 340 employees is losing market share to fintech competitors. Net new account openings are down 23% year-over-year. The board has authorized a $5M digital transformation budget for year one. The CEO needs a plan she can present to the board in 30 days. You have 8 hours. Build the complete transformation strategy: competitive analysis and market position assessment, digital product roadmap with prioritized initiatives, technology architecture recommendations, organizational change management plan, financial model with ROI projections for years 1-3, and a board-ready executive presentation. Constraint: you cannot recommend more than 15% headcount reduction. The board will scrutinize every assumption.
How your submission is evaluated.
Most strong candidates score 72-78 and do not pass.
Free resources to sharpen your skills before you attempt.
The Flux Challenge tests what you can produce -- not what you have studied. These free resources from Anthropic Academy can help you sharpen your skills before you attempt. None are prerequisites. All are worth your time.
Full-spectrum Claude API development. Flux-4 candidates building institutional-scale technical solutions need this foundation.
View courseIntegrating Claude Code into development workflows. Directly applicable for Flux-4 candidates solving complex business problems.
View courseAI governance, change management, and cyborg team design. The strategic judgment dimension at Flux-4 rewards exactly this kind of organizational thinking.
View courseBecause Flux-4 represents institutional-scale capability -- the ability to replace a division. At that level, good is not good enough.
Flux-4 submissions are evaluated against a six-dimension rubric covering problem comprehension, output completeness, domain breadth, execution quality, strategic judgment, and velocity signal. Each dimension is scored independently, weighted, and combined into a single 0-100 score. The 80/100 pass threshold means a candidate must perform strongly across all six dimensions; a single weak dimension can sink an otherwise strong submission. Scoring is grounded by web search of the live URL and GitHub repository submitted with the attempt.
Flux-3 rewards execution across functions. Flux-4 rewards judgment about which functions matter most, in what order, and why. The problem contains more ambiguity, more stakeholder complexity, and fewer explicit instructions. You are expected to identify what the problem actually is before you solve it.
You must hold an active Flux-3 credential to attempt Flux-4. The Flux Standard is a credential ladder -- each tier is earned in sequence and demonstrates that you have already cleared the bar one level below.
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Earned in sequence. No study guides. A real problem, a real time limit, and a fair result. Start with Flux-0 -- free during early access beta or attempt any tier directly.
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