Trust as Productive Infrastructure: Plaid, Passkeys, Identity

The client engaged Taller in 2023 for engineering capacity on a multi-year platform modernization. Taller ran multiple pods through 2026, from investment-management delivery to Azure platform engineering, plus embedded Scrum Masters, TPMs, and practice leadership.

The client’s anti-fraud and identity strategy called for two additions to its legacy platform: Plaid, a service that instantly verifies a person’s identity and connects their bank account, and passkeys, a way to log in securely without a password. Both had to be woven into the client’s older codebase without breaking its existing fraud-testing systems or the strict discipline around custodial accounting (the client held customers' money, so its records had to stay exact). In practice, that meant the new services had to be callable from the legacy applications, and the passkey sign-up flow had to handle cases where a passkey failed, falling back to another method without confusing the member.

Taller ran the Plaid integration team (dedicated frontend, backend, and QA engineers working against Plaid’s anti-fraud tools inside the client’s legacy platform). The work covered new automated test cases for the fraud checks, connection points the legacy applications could call, and user flows that handled Plaid’s instant-verification results alongside the older manual fallback (small test deposits used to confirm a bank account). A separate Identity team built the client’s authentication services (passwordless login, multi-factor authentication, and passkeys), writing the code with the help of GitHub Copilot, an AI coding assistant. The broader fraud- and anomaly-detection capability Taller drew on was anchored in a separate cybersecurity engagement, which served as the reference point for how to handle fraud in a regulated environment.