Powering the Commerce: How Aman Sardana Re-Engineers Card Authorizations For The Always-On Economy

Across the four major U.S. networks, purchase volume climbed to $10.2 trillion in 2023, a 6 percent jump from the prior year. Debit cards alone generate roughly 100 billion U.S. transactions annually, and a single network now carries 60 percent of that load. Most of those approvals still traverse vendor systems built for nightly batch windows, a mismatch that exposes issuers to latency, rising fraud pressure, and looming real-time settlement rails.

Aman Sardana at a Glance

“I’ve never seen a payment as just an API call; it’s a promise that must clear in the blink of an eye,” says Aman Sardana, a Midwest-based technology leader whose career began nineteen years ago writing software for one of the major e-governance initiative at the time in India. After stints modernizing banking stacks in London and Chicago, he now serves as the senior architect overseeing network-authorization strategy for a U.S. card issuer with a $75 billion deposits portfolio.

Colleagues recall his ascent from engineering lead to platform architect, capped by the company’s President’s Award for innovation in 2017. Sardana manages both roadmap and relationships—coaching product development teams on fault isolation while negotiating service-level targets directly with vendor CTOs. “My role is half diplomacy, half design,” he notes. That mix travels with him on the conference circuit: he shared system resiliency patterns at SREDay 2023 in London, a 150-person reliability engineering gathering from across the globe that spotlights cloud failure lessons, and unpacked architecting scalable platform services at CloudX 2024, a developer forum drawing thousands of architects.

Sardana’s community work extends to peer review. This year he joined judging panels for the Globee Cybersecurity Awards, where volunteers follow a multi-judge, data-driven scoring rubric designed to curb bias. “Evaluating dozens of entries sharpened my own sense of what ‘provably secure’ means,” he says. He also mentors junior engineers, often “pairing on design docs rather than code so they learn to reason in narratives.”

Inside the Transformation Blueprint

Since 2021 Sardana has spearheaded his card network’s multi-year move off a black-box vendor authorization engine and onto an in-house, cloud-native platform. The target envelope is steep: 5 billion annual transactions—about $300 billion in card spend—at 99.999 percent availability. “When every extra nine is a boardroom conversation, architecture becomes a risk discussion, not a tech one,” he observes.

His blueprint begins with using open source technologies like Spring framework for the core execution engine, state machine framework for workflow execution and distributed caching platform for low-latency in-memory processing. IaC templates in Terraform spin new regions in under an hour, while HashiCorp Vault encrypts payloads end-to-end so that PAN data remains opaque even to cluster admins. The rules engine itself is split into micro-policies—fraud, spend controls, and regional privacy checks—each deployable without a platform release. “We decoupled compliance from code drops; a regulator shouldn’t have to wait for sprint planning,” Sardana explains.

A servant-leader by habit, he codified “blameless incident drills” in which engineers from London to Chicago replay high-severity events, capturing latency deltas and toil scores. The exercise uncovered that 40 percent of rollout risk stemmed from non-functional regressions. “Finding that number let us argue for a green-blue cutover budget in plain dollars,” he says. Sardana also instituted SLA contracts that surface real-time health to SRE teams; if an authorization threshold wobbles, SRE can throttle non-essential flows before customer traffic feels it. “Operations owns the safeguard, product owns the feature—those lanes stay clear,” he adds.

What Next for Real-Time Rails

FedNow and tokenized card-on-file mandates are already nudging issuers toward millisecond decisioning. Sardana’s next experiments include confidential-computing enclaves—“processing the payload while it stays encrypted is the last mile of zero trust,” he says—and large-language models that distill transaction context into human-readable fraud reasons. He is also reviewing ledger-level attestation so that rule changes ship with cryptographic audit trails.

For institutions eyeing similar migrations, Sardana’s journey offers a pragmatic lesson: modernization is not a single launch but a cadence of reversible steps governed by clear risk appetites. “If we can swap in a new fraud model during lunch and nobody notices, that’s success,” he reflects. In an ecosystem where speed, trust, and compliance now share the same stopwatch, the quiet rigor of architects like Aman Sardana may be the decisive edge that keeps digital payments—already a $10-trillion American habit—both seamless and safe.

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