Salt Square

Fintech

Building a multi-tenant retirement platform at startup speed

Salt Square is the engineering team behind a New York fintech's multi-tenant retirement platform: full-stack delivery, AI-assisted automation and a migration off the legacy platform, run as an integrated team with the client's leadership.

The challenge

The client is replacing a legacy retirement platform with its own modern, multi-tenant product. They needed a delivery team that could carry the platform from feature development through production readiness and live migration, including tenant management, participant-facing dashboards, secure authentication and eventually mobile, without the cost and time of building a US-based engineering organization from scratch.

What we did

  • Fielded an established, mostly full-stack Salt Square team working as the client's core engineering group, with direct collaboration with leadership on hiring and team shape, including interviewing and selecting additional Salt Square engineers together with the client
  • Delivered iterative platform releases: multi-tenant management flows, a mobile-responsive participant dashboard, and production hardening ahead of live internal use for payroll and retirement accounts
  • Leaned on AI-assisted engineering for velocity: roughly 40 delivery automations produced in about two months, an AI QA agent for full-cycle test coverage, and an enterprise LLM toolchain with monitoring and guardrails
  • Implemented modern authentication and security: SSO via an identity provider, refresh-token handling, biometrics planned for mobile
  • Scoped the next phases with the client: a mobile proof of concept, DevOps ownership handover, and test and release process improvements
  • Planned and supported the migration from the legacy platform, targeting legacy shutdown by year-end

Results

  • The platform reached live internal production use, with the legacy migration scheduled and a year-end shutdown target
  • Sustained delivery pace: a recent monthly cycle landed roughly 70–80% of an ambitious planned scope, with the client adding scope and teams rather than trimming them
  • AI-assisted QA and automation embedded in the delivery process, not bolted on
  • An engagement that keeps expanding: mobile, DevOps and process streams added on top of core platform delivery

Tech

Multi-tenant SaaS architecture, React, SSO, AI QA agent, enterprise LLM tooling, CI/CD automation

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