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Vladislav Meshkov

Publications and source records attributed to Vladislav Meshkov.

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A Foundation Model for Multimodal Event Sequences in Financial Applications

Predictive modeling is a core component of modern financial services, where a wide range of tasks are traditionally addressed using separate models trained on manually engineered tabular features. This task-specific approach limits reuse and makes it difficult to fully exploit heterogeneous data sources such as transaction histories and digital interaction signals. In this paper, we present an approach based on pretraining a foundation transformer model on multimodal sequences of user events. Events from multiple data sources are unified into a single chronological sequence, enabling early fusion of heterogeneous modalities and learning of general-purpose representations via a next-event prediction objective. These representations are combined with existing engineered user features, on top of which lightweight neural models are trained for multiple downstream tasks. The proposed system outperforms traditional task-specific models while reducing development overhead. The approach was deployed in production at one of the biggest banks in Eastern Europe, resulting in measurable improvements in business metrics.

cs.LG

Closing the Curvature Gap: Full Transformer Hessians

The optimization landscape of Transformer models remains poorly understood despite their widespread adoption. While recent studies have derived curvature properties for isolated self-attention mechanisms, a comprehensive theoretical characterization of the full Transformer block, accounting for the interactions between Layer Normalization, Feed-Forward Networks (FFNs), and residual connections, is missing. In this work, we close this gap by deriving the exact, closed-form Hessian for the complete Transformer block under arbitrary twice-differentiable loss functions. We utilize rigorous matrix calculus to handle the non-linearities of LayerNorm and row-wise activations, establishing explicit spectral norm bounds for the resulting Hessian blocks. Our analysis reveals how different architectural components contribute distinct curvature mechanisms, identifying the specific curvature contributions of particular sub-layers. Furthermore, empirical validation against automatic differentiation confirms the exactness of the derived formulas up to numerical precision and shows substantial computational speedups for the closed-form Jacobian evaluations.

cs.LG