Fiscal decentralisation has placed the execution of substantial public budgets in the hands of small district-level treasury agencies, yet the determinants of performance in these units remain largely unexamined. This study estimated workload, work environment, and competence as simultaneous predictors of employee performance in the regional financial and asset management agency of a palm-oil producing regency in North Sumatra, Indonesia, using Job Demands–Resources and Conservation of Resources theory as the organising lens. A census of the agency’s civil-service establishment yielded complete responses from 32 employees on an 18-item Likert instrument. Ordinary least squares regression showed that the three predictors jointly explained substantial variance in performance, F(3, 28) = 22.045, p < .001, R² = .703, adjusted R² = .671. Workload carried the largest standardised coefficient and its sign was negative (b = −0.434, 95% CI [−0.811, −0.057], β = −.368, t = −2.357, p = .026), while work environment (β = .287, p = .033) and competence (β = .295, p < .001) were positive. The negative estimate contradicts the challenge-demand reading common in applied research: in error-intolerant, statutorily deadlined, audit-exposed work, quantitative load operates as a hindrance demand that depletes rather than mobilises. Managerially, the results favour redistributing peak-period load and rebuilding regulatory competence over incremental improvements to physical facilities. Estimates are reported with explicit attention to the precision limits of a 32-observation design.