Industrial financial systems operate on temporal event sequences such as transactions, user actions, and system logs. While recent research emphasizes representation learning and large language models, production systems continue to rely heavily on handcrafted statistical features due to their interpretability, robustness under limited supervision, and strict latency constraints. This creates a persistent disconnect between learned embeddings and feature-based pipelines. We introduce Embedding-Aware Feature Discovery (EAFD), a unified framework that bridges this gap by coupling pretrained event-sequence embeddings with a self-reflective LLM-driven feature generation agent. EAFD iteratively discovers, evaluates, and refines features directly from raw event sequences using two complementary criteria: alignment, which explains information already encoded in embeddings, and complementarity, which identifies predictive signals missing from them. Across both open-source and industrial transaction benchmarks, EAFD consistently outperforms embedding-only and feature-based baselines, achieving relative gains of up to +5.8% over state-of-the-art pretrained embeddings, resulting in new state-of-the-art performance across event-sequence datasets.
Figures & tables
Figure 1: Blind spots of embeddings. Coefficient of determination ( R2 ) of a feature reconstruction based on embedding representations CoLES, NTP, and LLM4ES on the Rosbank dataset. Values highlight systematic representational blind spots across embeddings.
Figure 2: Overview of Embedding-Aware Feature Discovery (EAFD). (a) Latent embedding pipeline mapping event sequences to continuous user representations. (b) EAFD agent loop: an LLM-based generator proposes interpretable features from raw sequences, evaluated by embedding–feature alignment and downstream utility, with reflective updates guiding iteration. (c) Feature outcomes: aligned features recover information encoded in the embedding, while complementary features capture predictive factors missing from it. (d) Embedding–feature space decomposition into latent, interpretable, and blind-spot regions. (e) Deployment and refinement: discovered features improve downstream tasks and support targeted encoder refinement (e.g., coverage, robustness, privacy).
Method
Age
Gender
Rosbank
DataFusion
Acc
Δ %
AUC
Δ %
AUC
Δ %
AUC
Δ %
CoLES
0.645
–
0.888
–
0.835
–
0.738
–
NTP
0.540
–
0.849
–
0.798
–
0.648
–
LLM4ES
0.651
–
–
–
0.849
–
–
–
Agg Features + CoLES
0.649
+0.62
0.889
+0.11
0.832
-0.36
0.740
+0.27
Featuretools + CoLES
0.644
-0.16
0.889
+0.11
0.863
+3.35
0.760
+2.98
Table 1: Performance comparison of EAFD against baseline embeddings and feature-based agents. Relative improvement ( Δ %) is reported w.r.t. the corresponding backbone embedding. Standard deviations are approximately: Age ±0.004 , Gender ±0.007 , Rosbank ±0.005 , DataFusion ±0.008 .
Figure 3: EAFD iteration dynamics of Rosbank validation ROC-AUC and feature composition across EAFD iterations.
Method
Private Dataset
Age
Gender
Regression
CoLES
0.743
0.898
11373
NTP
0.736
0.895
10839
LLM4ES
0.692
0.789
11462
EAFD (CoLES)
0.756 (+1.75%)
0.901 (+0.33%)
10933 (-3.87%)
EAFD (NTP)
0.739 (+0.41%)
0.897 (+0.23%)
10671 (-1.55%)
Table 2: Performance comparison on the Private Dataset across classification and regression tasks. Percentages denote relative change with respect to the corresponding base embedding; for regression, negative values indicate MAE reduction (improvement).
Figure 4: Task-adaptive distribution of discovered feature types. Feature category proportions generated by EAFD for age, gender, and regression tasks.
Category
Base Encoder
Enhanced Encoder
Amount ( R2 )
0.451
0.484 (+7.39%)
Category ( R2 )
0.816
0.687 (-15.85%)
Time ( R2 )
0.327
0.608 (+85.68%)
Other features ( R2 )
0.897
0.870 (-3.07%)
Downstream (AUC)
0.835
0.845 (+1.20%)
Table 3: Reconstruction Score R2 of feature classes from embedding representations and downstream performance on the Rosbank dataset between Base and Enhanced Encoder.
Figure 5: Selective feature erasure in embeddings. Top panels show R2 reconstruction performance before and after erasing mcc (a) and trx_amount (b) feature categories, while the bottom panels report the corresponding relative performance change ( ΔR2 ).
Llama3.1-8B
Llama3.3-70B
gpt-oss-20B
gpt-oss-120B
0.835
0.856
0.859
0.872
Table 4: EAFD performance on the Rosbank (AUC) for different LLM generator backbones.
Method
NTP
CoLES
Embeddings
0.648
0.738
Featuretools
0.728 ( +12.3% )
0.760 ( +3.0% )
OpenFE
0.730 ( +12.7% )
0.753 ( +2.0% )
LightAutoML
0.731 ( +12.8% )
0.760 ( +3.0% )
LLMFE
0.728 ( +12.3% )
0.760 ( +3.0% )
CAAFE
0.750 ( +15.7% )
0.762 ( +3.3% )
Table 5: Comparison of automated feature engineering methods across different embeddings.
Steklov Institute of Mathematics Saint Petersburg, Russia · Independent Researcher Belgrade, Serbia · ISP RAS Steklov Institute of Mathematics Saint Petersburg, Russia +4