SIMBI
A national time-bank for skill-trade economies, run as a nonprofit since the pandemic taught us how much we need each other.
Simbi is the largest skill-exchange platform in the United States and one of the longest-running attempts at a national community currency in the contemporary internet era. People list what they can offer — a haircut, a guitar lesson, a logo, an hour of moving help — and accept “simbi” (the in-system credit) as payment. Members earn simbi by giving their time and spend it by receiving someone else’s. Money never enters the loop.
I joined the platform as an early enthusiast in 2018, took on the formal Presidency in 2021 in the wake of the original founder’s transition, and have stewarded it through the long quiet of post-pandemic platform fatigue. The 501(c)(3) was reincorporated under my watch; the technical platform, the community programs, and the relationships with adjacent time-banking organizations live or die on the volunteer hours that flow through the work.
What it is, technically
Simbi is a Rails monolith with a Vue 2 front-end, an Elasticsearch-backed search and recommendation engine, Sidekiq for background jobs, and a Postgres + Redis substrate behind the scenes. It runs on AWS in a single region. At its busiest the platform served high-five-figure monthly active users; today it sits at a steady core of committed time-bankers who have been trading skills for the better part of a decade.
The codebase is, by any standard, old. The original platform shipped on Rails 5 and Ruby 2.7 in an era when those were current; the world moved on, and the platform — kept alive by volunteer hours and a tight infra budget — did not. Modernization was the last decade’s deferred maintenance.
The 2026 modernization
In April 2026 I led a four-wave platform refresh that ran on a parallel staging stack while production stayed untouched. By the end of the wave:
- Ruby moved 2.7 → 3.2.6 (latest stable, with the YJIT performance improvements turned on)
- Rails moved 5.2 → 6.1.7.10 (a deliberate one-major-version step rather than a leap to 7.x; the kernel-level changes between 6.1 and 7 are large enough to warrant a separate wave)
- Elasticsearch moved 2.x → 7.17.27, with a corresponding upgrade of the Searchkick gem to 4.6
- Vue moved 0.12 → 2 (a five-year-overdue leap; the existing component tree was minimal enough to migrate inside a single sprint)
- Sidekiq moved 5 → 6.5 with redis-rb on a current major
- Stripe stayed pinned at 7.1 — newer SDK versions broke an API surface used by the donation flow that we’ll address as its own gated change
Production still runs the legacy stack. Every cutover gate requires explicit approval and a tested rollback plan; some of these systems are older than the staff at most of the nonprofits that depend on them.
What it has cost
The platform’s ongoing AWS bill sits at roughly $548/month in us-west-1 — already heavily right-sized after a 2026 audit, and slated for another $110-155/month reduction in the next infrastructure wave. Intercom, the conversational customer-support tool, dwarfs everything else at $800/month and is the largest single line item the nonprofit carries. The remainder is volunteer hours.
What it is becoming
The next chapter is not just “Rails 7”; it is asking the harder question of what a healthy community-currency platform should look like in a 2026 internet, where AI matchmaking is suddenly tractable, where federation is starting to mean something again, and where the gravity of mainstream social media is at its weakest in a decade. Whatever Simbi becomes next will be charted in the open. Notes from the field will appear on the writing shelf as the work proceeds.