Corebaseit

I’m Vincent Bevia. I work in payments at MultiSafepay (part of Ant Group), and I’ve spent years focused on POS architecture, EMV, and cryptography. I’m also the author of Point-of-Sale Systems Architecture — Volume 1 and The Obsolescence Paradox: Why the Best Engineers Will Thrive in the AI Era.
This blog is my space to share what I’m thinking about, learning, and discussing: POS systems, EMV, Payment Security, and, increasingly, about AI in general and how AI is reshaping this field. I also draw on my background in Electrical Engineering and Telecommunications — information theory, stochastic processes, and thermodynamics — the technical foundations that sit beneath much of this work.
Less corporate, more personal. Opinions, reflections, and the kind of things I’d talk about over coffee.

Topics I care about

POS & EMV — how terminals, chips, and contactless payments actually work
Cryptography & security — DUKPT, HSMs, and key management in the real world
AI in payments — where it helps, where it doesn’t, and what’s coming next
Engineering foundations — telecommunications, information theory, and stochastic processes

If you’re building payment technology — or just curious about how it all fits together — welcome.

Maximum Entropy Inverse Reinforcement Learning: Understanding the Trajectory Formula

Inverse reinforcement learning (IRL) asks a different question from classical RL: instead of assuming a reward function and learning a policy, you observe expert behavior and infer what reward would …

Markov Decision Processes: The Mathematical Foundation of Reinforcement Learning

The Markov Decision Process (MDP) is the standard formal object for sequential decision-making under uncertainty. It separates problem definition — states, actions, how the world evolves, what you …

Reversals, Refunds, and Chargebacks: Decoding the Payment Lifecycle

Three words every payment professional uses — and confuses. Each lives at a different point in the settlement lifecycle, under a different protocol, with radically different consequences.

Edge AI: Why Intelligence Is Moving to the Boundary — and What It Takes to Get There

There is a quiet architectural shift happening beneath the surface of the AI conversation. While the public discourse fixates on data center GPU clusters and trillion-parameter models, a different …

Feasibility Assessment: Q-Learning Suitability for Organizational Decision Systems

Q-learning for production decision systems: when tabular or deep Q-networks (DQN) make sense, state–action limits, stationarity, exploration cost, convergence risks—and when to say no. Reinforcement …

Syntactic Fluency, Semantic Fragility: Why AI Masters Form but Stumbles on Meaning

Your favourite AI can compose a flawless sonnet, generate syntactically perfect ISO 8583 messages, and produce compilable C++ on the first attempt. Ask it whether that ISO message actually makes …

CAPKs: The Cryptographic Trust Anchors Behind Every EMV Transaction

Every card-present transaction begins with a question the terminal must answer before anything else: is this card genuine?

What Actually Happens in the 2–3 Seconds of a Card Payment

A card payment feels instantaneous. The system behind it is not.

POS Architecture Beyond Certification: Financial Infrastructure, Fraud Detection, and the Expanding Attack Surface

The POS terminal has quietly become critical financial infrastructure — and most architects are still designing it like a payment endpoint.

Reasoning Models and Deep Reasoning in LLMs: Chain-of-Thought, Tree of Thoughts, and Test-Time Compute

Language models don't reason. Not in the way humans do.