Case study
Helping Lettuce grow from a tax app into a full platform for the self-employed, without starting over
- Client
- Lettuce, which runs taxes, bookkeeping, banking, payroll, and benefits for people who work for themselves
- Our role
- Part of Lettuce’s engineering team since day one
- Length
- Since 2023, ongoing
Lettuce’s milestones
- March 2024Launched tax and accounting automation; $6M seed round
- June 2024Launched an AI assistant for tax questions
- August 2024$15M Series A
- November 2025$28M round and acquired Besolo to add health benefits
- April 2026Acquired Carry to add retirement accounts
The situation
Lettuce launched in 2024 to handle taxes and accounting for self-employed people: creators, real estate agents, therapists, consultants, truck drivers, and others, many earning over $100K. It kept adding products while the first ones were still growing: business banking and debit cards, invoicing and payroll, S Corp setup, an AI assistant, and, most recently, health, dental, vision, and accident coverage through its own employer organization, now offered in 15 states.
Every one of those products touches money or sensitive data, and health benefits added a second set of rules on top of the financial ones. Tax season brings sharp spikes in use, when a small slowdown or calculation error becomes a customer emergency. And code written to launch the first product had to carry all of it, through three funding rounds and the scrutiny that comes with each.
What we did, working with Lettuce’s team
- 01
Made the platform hold up at tax-season peaks: the money calculations, the background work that retries failures, and the connections to outside partners.
- 02
Made the money math clear. We reworked the places where tax, accounting, and payment logic meet, so engineers, finance, and support can all follow them.
- 03
Made partner connections consistent across banks, payments, and new partners as one product became many.
- 04
Added the controls a money-moving business needs: visibility into financial flows, tools to recover from failures, and records that hold up under review.
- 05
Kept the foundation ready for what came next. Banking, the AI assistant, and health benefits were added on the same platform rather than as separate rebuilds, including the move into health data, which comes with its own rules.
What changed
More predictable performance through tax-season peaks.
Money calculations that engineers, finance, and customers can reason about.
Banking, an AI assistant, and health benefits added without rebuilding the foundation.
The same platform carried Lettuce from launch through three funding rounds totaling $49 million.
Why it matters to you
Most early code is written to launch, not to last. We know how to make it last, without throwing it away and starting over.
Is your software ready for what’s next?
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