01
Rails consulting
Code review, upgrade paths, performance audits, and senior pair-hours inside your repo. Billed by the hour.
tiny_prism_llc
· Sheridan, WY · est. 2019
Rails + AI,
by a senior engineer
who ships.
A one-person studio for teams that want thoughtful web software — readable tests, reviewable PRs, and a repo left tidier than we found it.
Selected engagements · 2022 – 2026
Northwind / rails
Meridian / api
Bluemark / stripe
GraniteOS
Fieldwork.co
About · 01
A small studio
A small studio
with a long memory.
Tiny Prism LLC is a one-person consultancy in Sheridan, Wyoming. Twenty years in Rails, three of them spent deep in LLM tooling. We work with three to four teams a year — usually for six to twelve weeks at a time.
Andy Wang
Principal · Sheridan, WY
Senior Rails engineer since 2004. Previously staff at two YC-backed startups. Lives at 4,200 ft.
We take work that's well-scoped, technically interesting, and where the team values readable code over a fast tour through it. Most of our engagements are Rails monoliths between Rails 6 and 7.2, often with a Postgres / Sidekiq / Stripe spine and an LLM layer somewhere in the middle.
What you actually get: a senior pair of hands in your repo within a week. Friday demo videos instead of status decks. A runbook, tests, and an architecture note when we're done — so the next person to touch it can.
If something is outside our four sanctioned capabilities, we'll tell you within a day and usually refer you to someone better suited. We'd rather pass than half-ship.
21yrs
Writing Ruby
63
Engagements shipped
100%
Repeat-or-referral rate
1d
Median brief turnaround
What we do · 02
Four things,
Four things,
done well.
Engagements are scoped around one of four capabilities. Anything outside them, we'll tell you upfront — and usually refer you to someone better suited.
02
LLM integration
Retrieval pipelines, evaluations, tool-calling. Built inside production Rails apps — not next to them.
03
Stripe & payments
Connect, Billing, and webhook plumbing built to pass audit — and survive a Black Friday traffic spike.
04
SaaS from scratch
Turnkey Rails 7.2 + Postgres + Hotwire. Auth, billing, admin, and deploy on day one.
05
API design
Versioned JSON APIs your clients will actually enjoy using. OpenAPI, documented and tested.
—
Not sure which?
Send a brief paragraph. We'll tell you within a day whether it's a fit, and what it might cost.
Send a brief
Stack · 03
Where our
Where our
hours actually go.
The tools we reach for first. We're not trying to be polyglots — depth in a small stack beats breadth every time.
Ruby on Rails since 2.3 · daily driver
96
PostgreSQL schema, query plans, partitioning
90
Hotwire / Stimulus Turbo native, Streams, drives
88
React / TypeScript where Hotwire isn't the right call
80
LLM tooling OpenAI, Anthropic, evals, RAG
85
Stripe Connect, Billing, webhook hygiene
92
AWS / Heroku / Fly boring infra is best infra
84
How it goes · 04
Four steps,
Four steps,
roughly six weeks.
Every project runs on the same cadence. You'll always know what's next, what we're blocked on, and what's shipping this Friday.
STEP / 01
Brief & read-through
An hour on a call, then a day in your repo and your docs. You get back a one-page plan with a fixed quote and a start date.
~ 2 days · free
STEP / 02
First PR inside a week
A real, reviewable pull request against main — usually a small win or a visible stake in the ground. Sets the cadence for everything after.
Week 1
STEP / 03
Build, Friday demos
Every Friday: a 15-minute recorded walkthrough of what shipped, what's in review, and what's next. No status decks, no theatre.
Weeks 2 – 5
STEP / 04
Handoff & 30 days of support
Runbook, test suite, and an architecture note you can hand to your next hire. Thirty days of follow-up included, whether you need it or not.
Week 6 +
Case study · 05
The work,
The work,
one project at a time.
A recent engagement — typical scope, typical pace. Other write-ups available on request; everything we ship is under NDA by default unless the client wants to talk about it.
Case study · 004 — Northwind Logistics
LLM-assisted invoice review, shipped to 40 ops staff in five weeks.
A Rails 7 monolith with a legacy approval workflow. We added an evaluation harness, a retrieval step over their contract library, and a tool-calling model that drafts an approval decision a human confirms in one click.
Ask for the write-up4.2×
Throughput per reviewer
0
Incidents · 6 mo post-ship
97%
Model + human agreement
Recent engagements · 2023 – 2026
9 of 22 shown
22
Bluemark — Stripe Connect migration
Standard → Express, with a clean payout reconciliation pipeline.
rails · stripe · sidekiq 2026 · Q1 21GraniteOS — internal RAG over runbooks
Retrieval over 1,400 ops docs; cited answers in Slack and Linear.
rails · pgvector · openai 2025 · Q4 20Fieldwork — Rails 6 → 7.2 upgrade
Strangler-pattern upgrade with zero downtime. 600+ specs untouched.
rails · postgres · rspec 2025 · Q3 19Meridian — public API v2
Versioned JSON:API spec with OpenAPI docs and a Ruby SDK.
rails · openapi · rswag 2025 · Q2 18Northwind — LLM invoice review
Featured above. 5 weeks, 40 daily users, 4× throughput.
rails · anthropic · evals 2025 · Q1 17Confidential — SaaS from zero
Greenfield Rails monolith with billing, auth, admin, deploy.
rails · hotwire · kamal 2024 · Q4
In-house · 06
Products we ship
Products we ship
under our own name.
Small SaaS tools we built for ourselves, then opened up. Each one is a Rails monolith maintained by the same person who answers your support email. Real customers, real revenue, no VC.
ReplyMasterreplymaster.app
AI-drafted customer-support replies that sound like your senior agent on a good day. Trained per inbox, with an eval suite so you can ship prompt changes without crossing your fingers.
Built originally as an internal tool for a Northwind support team drowning in tickets. Now serves ~140 teams from Rails 7.2 with a Hotwire admin, Stripe Billing, and a small evaluations harness so each customer can tune voice without breaking the others.
140+
Paying teams
2.1M
Drafts shipped
$29
Starting / mo
rails 7.2 · hotwire · anthropic · stripe
replymaster.app
BrakemanCIbrakeman.ci
Brakeman + bundler-audit + dependency-review on every Rails PR, with sane defaults and one-line GitHub Action setup.
rails · gh actions · brakeman
brakeman.ci
StripeReplaystripereplay.dev
Inspect, diff, and replay any Stripe webhook against your local Rails app. Made it for ourselves on every Stripe project; turns out everyone needed it.
rails · stripe · sidekiq
stripereplay.dev
ShipNotesshipnotes.app
A 15-minute Friday-demo recorder for engineering teams. Record, caption, ship to Slack in one click — what we use on every client engagement.
rails · hotwire · ffmpeg
shipnotes.app
PgQuery Watchopen source
A tiny Rails gem that surfaces your top-10 slow queries in development, inline with the request log. Free, MIT, 2.3k stars.
rails · postgres · ruby gem
github.com/tinyprism/pgquery_watch
All products run on infrastructure we operate · same person on support & engineering
Have an idea you want built like this?
Engagements · 07
Two ways
Two ways
to work together.
Hourly when you have the team and just need senior eyes. Fixed-scope projects when you need something built end-to-end. No retainers, no minimum contract length past the first ten hours.
$150/ hour
Senior pair-hours inside your repo. Best when you have the team — you just need a second set of experienced eyes.
- 10-hour minimum, topped up as needed
- Async reviews on your PRs, same business day
- Weekly pairing session or two, your cadence
- Slack / Discord / GitHub access
- No long-term commitment, cancel any Friday
From $5k
A scoped deliverable — a working integration, a new service, or a green-field app. Fixed scope, fixed bid, weekly demos.
- Written plan & quote within 2 days of the brief
- First PR against
maininside a week - Friday demo + changelog, every week
- Handoff runbook, tests, and architecture note
- 30 days of follow-up support, included
Words from the people who hired us · 08
What clients
What clients
actually say.
References available on request — for everything below, with names. We don't post highlight reels; this is what people wrote in the post-engagement email.
Three weeks in, Andy had untangled a Stripe Connect migration we'd been kicking around for a year. The PRs were small enough we could actually review them. Hire of the year, frankly.
Sarah Johnson
CTO · TechStart Inc · 2025
We brought Tiny Prism in for what looked like a two-week LLM spike. They came back with an evaluation harness on day three and saved us from shipping something we'd have regretted by Q3. Fully recommended.
Michael Chen
Head of Product · DataFlow · 2024
The thing I keep telling people: the handoff document was better than most of our internal docs. Six months later, our junior dev is still using it as the first stop when something breaks.
Jennifer Martinez
Founder · EduTech Platform · 2023
We're a Rails 6 shop. We needed to ship a multi-vendor marketplace in nine weeks. Tiny Prism shipped it in seven and the test suite is still the cleanest in our monolith.
David Thompson
VP Engineering · MarketPlace Pro · 2024
Andy spent the first week mostly listening, which I appreciated. The compliance work he ended up doing for our PSP migration was so unglamorous that I want to mention it specifically. Thank you.
Lisa Rodriguez
Director of Tech · FinanceFlow · 2023
The Friday demo videos are the thing. Twenty minutes a week, and our whole leadership team knew exactly what was happening in the codebase. I've already stolen the practice for internal teams.
Alex Kumar
Lead Dev · CloudTech · 2024
Get in touch · 09
Tell us about
Tell us about
your codebase.
A paragraph is plenty. We read every brief and reply — typically within one business day — with either a yes, a no, or a referral to someone better suited.
Emailhi@tinyprism.com
Calendarcal.com/tinyprism/intro
GitHubgithub.com/tinyprism
Studio1544 Coffeen Ave, Sheridan, WY · MT
SLAReplies within 1 business day