Acquiring fraud detection. Less friction. Less loss. Governed AI.
CyberAntifraud is my applied PhD hub at NOVA IMS, focused on fraud detection in merchant acquiring. I work at the intersection of fraud analytics, deep learning, and operational delivery. The goal is simple. Reduce false positives without losing fraud capture, and reduce false negatives without breaking governance.
Temporal Integrity Gate
time awareCost and Friction Engine
net benefitGovernance Trace Layer
audit readyData disclosure policy. No sensitive operational data is published. Public examples rely on synthetic or anonymised aggregates.
Offer for fraud teams
What I can deliver
- Time aware evaluation protocol, rolling windows, leakage controls, reproducible reporting.
- Cost model and threshold policy: net benefit curves, friction budget, capacity constraints.
- Model benchmarking: strong baselines first, deep learning only when it wins under temporal backtests.
- Governance pack: model cards, release gates, monitoring plan, rollback triggers, audit evidence.
Practical scope. Acquiring fraud, card present and e-commerce. Design for regulated environments.
Engagement modes
- Advisory review of your current stack and evaluation practice. Findings, risks, concrete fixes.
- Hands on build of the evaluation harness and governance templates, ready for production use.
- Benchmark sprint: baseline suite, temporal CV, cost curves, recommendation with evidence.
- Enablement: train analysts and engineers to run the pipeline and keep it honest under drift.
You keep ownership. I deliver the method, artefacts, and evidence trail.
Credibility signals
PhD at NOVA IMS Acquiring domain focus Time aware validation Cost sensitive evaluation Audit ready governance Reproducible artefactsThis site is the public face of the method. Private engagements remain private. Nothing sensitive is published here.
Research focus
Research questions
- How can we reduce false positives while preserving or improving fraud capture under strict time aware validation?
- How should we evaluate models when the real target is net benefit, not accuracy?
- How can we detect and control drift in acquiring, where merchant and attacker behaviour evolves continuously?
- How can governance, auditability, and human oversight be operationalised without reducing performance?
Scope. Card present and e-commerce acquiring. Merchant context. Behavioural signals. Cost aware decision policies.
Facts and figures
Core outputs on this hub
Evaluation protocol Cost model note Model card template LLM attack simulation Operational explainabilityProtocol and templates
Evaluation protocol
Fraud data is non stationary. Random splits are misleading. This work uses blocked time series validation and rolling windows to approximate production reality, quantify drift sensitivity, and prevent leakage.
PDF. Download
Cost model note
The primary KPI is expected net benefit. False positives create friction and operational cost. False negatives create direct loss. This note defines assumptions, constraints, and reporting requirements for threshold selection.
PDF. Download
Model card template
Audit ready documentation. Model overview, data windows, temporal results, drift monitoring, governance sign off, and rollback criteria.
PDF. Download
Governance and ethics
Governance principles
- Data minimisation and explicit purpose limitation for anti fraud.
- Documented lineage. Data version, features, training window, parameters.
- Human oversight for high impact decisions with clear accountability.
- Auditability by design. Logs, model cards, decision traceability.
Operational explainability
Explainability is treated as an operational instrument. The goal is to enable analysts, risk teams, and auditors to understand why a decision occurred and how stable that reason is under drift.
Policy. Privacy and data disclosure
Disclosure statement
No production secrets, sensitive rules, merchant identities, or personal data are published. Public materials use synthetic data or anonymised aggregates. Any public robustness demonstrations are designed to inform defence, not enable abuse.
Papers and outputs
| Work | Status | Focus | Links |
|---|---|---|---|
| Survey Deep learning for acquiring fraud detection | In progress | SLR, metrics, temporal validation, robustness, governance | Preprint coming soon |
| Methods Temporal CV and cost model | Planned | Protocol, cost curves, drift control, baselines | Draft coming soon |
| Results Models vs baselines on acquiring context | Planned | Model families, operational trade offs, governance | Draft coming soon |
| Fraud attack simulation Robustness harness | Planned | Attack scenarios, canary tests, evaluation harness | GitHub link coming soon |
If you want a fast view of my work, start with the protocol PDFs, then reach out by email with your constraints.
Contact
Paulo Saramago • Lisbon, Portugal
Academic email: psaramago@novaims.unl.pt
LinkedIn: linkedin.com/in/saramago
Alternative email: psaramago@gmail.com
For academic collaboration or applied work, include: acquiring context (card present or e-commerce), your current validation split strategy, main pain (false positives, false negatives, drift, governance), and any constraints (latency, ops capacity, audit requirements).