Kelly (Nasdaq: KELYA, KELYB) said human capital constraints are the largest bottleneck to U.S. data center development as AI investment and cloud infrastructure drive a historic buildout. Its 2026 Data Center Salary Guide says 90% of operators identify staffing shortages as a critical constraint, while about half of U.S. data centers scheduled for delivery in 2026 are expected to face delays or cancellations. Data center pay varies by 46 percentage points across U.S. markets, from 34.2% above the national average in Silicon Valley to 11.8% below it in Omaha. National midpoint salaries range from $112,000 for Data Center Technician SMEs to $178,000 for Data Center Operations Leaders. Permanent data center employment is projected to reach 650,000 positions in 2026, up 30% from 2023, while related construction jobs are expected to exceed 180,000 through 2028. With 25% of personnel hired away by competing hyperscalers and other operators, Kelly recommends recruiting from adjacent industries and using rapid upskilling programs to expand the talent pool.