I help founders build repeatable and reliable reasoning systems.
Vicente Reig Rincón de Arellano — Fractional Engineering Lead since 2020
Founders and execs bring me in at inflection points. I help them ship through the transition.
20 years shipping software—New Relic, Apple, Atlassian. Now I build product, lead small teams, and maintain DSPy.rb. I got tired of prompting LLMs and wanted to program them instead—turns out other people felt the same way.
My clients are early-stage. Bootstrapped founders chasing revenue. Funded teams chasing growth. Both have proof it works. Both need proof it scales.
Let's talk. hey@vicente.services
I'm also on Twitter, LinkedIn, and GitHub. Talks and blog too.
The Work
Technical Transitions
Navigate the Series A → B inflection point. At
Finalis, early decisions no longer fit their scale—
a system built for millions when reality was thousands. I guided simplifying 23 microservices into a monolith that matches their actual success ($10M ARR). At
Tray.ai, refounded the Education Squad and rebuilt the documentation platform—20 content writers now ship without engineering bottlenecks. At
StaffingReferrals.com, optimized response times from minutes to sub-second.
Reasoning Systems
Turn your AI experiment into a
production-ready system. At
Bounti.ai, I stabilized a GenAI prototype into a pipeline powering their AI Sales Assistant ($800K ARR). At
Medicoder, designed EHR integrations and LLM classification pipelines for PHI/PII in skilled nursing facility workflows. At
Apple, built the Classifier & Recommendation System processing customer feedback across macOS, iOS, and tvOS.
Engineering Rhythm
Coach teams to ship faster with less friction. At
Apple, moved from fortnightly releases to
daily continuous delivery. At
New Relic, established onboarding that got new hires shipping in their first week. At
Atlassian, built 24/7 on-call and incident management practices.
Full Product Build
From
napkin sketch to revenue. Not just code — positioning, operations, team. At
Scout Fuel, I partnered with co-founders from PMF discovery through production: built the MVP, automated fuel pricing ingestion across North America, set up customer reporting. They now distribute 5M+ gallons/month.
Team Building
Build and lead the engineering team as your business grows. At
Atlassian, led 10 engineers on the Experimentation Platform (P99 5ms, 24/7 on-call). At
New Relic, built a team of 8 driving
$1MM quarterly self-serve revenue. At
Apple, scaled from 3 to 80 web instances + 94 background workers. At
Scout Fuel, hired and coached the team that built the first marketable version.
The Writing
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We've built systems that can't explain themselves. The problem isn't accuracy. It's auditability. When it's wrong — and it will be wrong — can you explain what happened?
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Turns out my body has been keeping receipts. Sleep quality predicts next-day stress with uncomfortable accuracy. When restorative sleep drops below 30%, average stress jumps to 38. Above 45%? It's 24.
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My feed is full of Takes™ about when AI will replace us. I'm more interested in when it replaces dashboards. The charts are fine. However, a clear explanation would be better.
See all posts →
The Rates
A typical contract is for 1 month of work. I am normally booked 1 to 3 months in advance.
I am open to shorter contracts, but prefer longer ones. For shorter contracts, we will divide my monthly rate by the number of days you want, and add a small amount of overhead.