J/SJohn SandovalSolutions architect & builder

Solutions architect. Self-taught builder.

I went from answering support tickets to building the software behind them. These days I’m a Solutions Architect at Extend, and I’m building Fleet on the side.

See what I’m building The backstory
Sacramento, California38.58° N / 121.49° W
THE WAY I BUILDFLEET / 03
Follow the work through.Fleet follows pull requests through checks and review feedback. The agent’s session can end. The work keeps its context.
The route hereIT operationsCustomer supportAI engineeringSolutions architecture
Products. Tools. Things I wanted to try.Explore the collection

01 In the works

Built because
I wanted to use it.

Independent work
From idea to implementation
A workspace for coding agents
fleet↗
YOUR IDEAAGENTS AT WORKYOUR REVIEW
Claude Code + CodexBuilt in Rust

Creator / Product + architecture

The session ends.
The work doesn’t.

I built Fleet to keep coding-agent work from turning into a second job of managing terminals, branches, and review comments.

It runs Claude Code and Codex across repositories, gives each contribution its own worktree, and follows pull requests through checks and feedback. You still decide what gets merged.

I wrote it in Rust.
I didn’t know Rust when I started.

Visit Fleet Read about the build

Before Fleet

No More Work AI

Co-founded an AI Chrome extension used by 10,000+ professionals for writing, support, and everyday web workflows.

2023All 10 projects

From the public repos

More things I’ve built.

Browse all projects
Open source / Library + CLI2026

Meaning Assert

Natural-language assertions for AI outputs. Checks the meaning against a requirement and supplied evidence, with pass, fail, or inconclusive results.

Separates the model’s judgment from the assertion policy. Includes TypeScript declarations and test-runner examples.

  • JavaScript
  • Node.js
  • Jev
Source Recorded demo
Open source / Code review2026

Meaning Diff

Reviews Git diffs for weakened assertions, hidden failures, and implementations replaced with placeholders. Findings stay attached to the exact before-and-after hunk.

A Node.js CLI and library with Jev-backed judgments, limited local rules, and inspectable HTML reports.

  • JavaScript
  • Git
  • Semantic review
Source Recorded demo
Open source / Starter kit2023

Next.js + LangChain Starter Kit

69 stars / 8 forksGitHub · Oct 2026

A chatbot starting point built to be easier to understand and reuse. Includes chat windows, message inputs, assistant cards, and API-key input components.

Started because existing templates felt too complicated. Reusable components were the point.

  • TypeScript
  • Next.js
  • LangChain
Source
Open source / Testing sample2026

AI Extraction Regression Check

An offline Python checker that compares saved JSON extraction outputs and shows which cases improved, stayed broken, or regressed.

Synthetic fixtures demonstrate why a higher aggregate score can still hide a newly broken field. No model API or third-party packages required.

  • Python
  • Regression testing
  • JSON
Source

02 The experience

From support
to system design.

Full resume

I’ve been the person answering the ticket, writing the workaround, building the integration, and designing the system. Here’s how that happened.

2026ExtendSolutions ArchitectMay 2026 — PresentCURRENT

I build AI-powered products and enterprise tools, from the initial idea through architecture, implementation, and adoption.

  • Connect AI capabilities to existing business systems and the workflows people already use.
  • Combine hands-on development with product direction and architectural thinking.
2024XurrentSolutions EngineerSep 2024 — May 2026

Joined as an AI Engineer in September 2024, moved into Solutions Engineering a year later, and left in May 2026 to join Extend.

Solutions EngineerSep 2025 — May 2026
AI EngineerSep 2024 — Sep 2025
    2022UserTestingAI EngineerMay 2022 — Sep 2024

    Started in customer support and moved into engineering. A lot of my work began with a customer problem that the product didn’t have a straightforward answer for.

    AI EngineerApr 2024 — Sep 2024
    Technical Support EngineerJul 2023 — Apr 2024
    Customer Support SpecialistMay 2022 — Jul 2023
    • Built product demos and custom solutions with Chrome extensions, Figma plugins, Slack integrations, and server-based proofs of concept.
    • Worked with cross-functional teams on product limitations, technical workarounds, and customer-facing explanations.
    • Progressed through customer support, technical support, and AI engineering.
    2020Berkshire Hathaway HomeServicesElite Real EstateSenior IT AdministratorJun 2020 — May 2022

    Supported the technology behind a real estate office of more than 350 agents, and built tools to take repetitive work off their plates.

    Senior IT AdministratorDec 2020 — May 2022
    Assistant IT AdministratorJun 2020 — Dec 2020
    • Built a tool for creating marketing posters from templates and sending them to email lists.
    • Handled agent support and worked with the corporate team on systems security.
    2020Pacific Wholesale MortgageSenior IT AdministratorJun 2020 — May 2022

    Helped support a growing mortgage business as it reached 750 active loan officers and more than 3,000 registered users.

    Senior IT AdministratorDec 2020 — May 2022
    Assistant IT AdministratorJun 2020 — Dec 2020
    • Built a backend loan payment tracker and payout system with React and the Stripe API.
    • Built an onboarding flow that let new users create their own accounts.
    • Provided technical support and coordinated technology integrations.
    Open a role for the details.Projects, skills, and the full story

    03 On my mind

    A place to
    work things out.

    All writing
    AI & architectureOctober 30, 2026 / 4 min

    I built Fleet without knowing Rust.

    The language wasn’t the hard part. Deciding how the system should work was.

    John Sandoval outdoors, holding a baby with a pumpkin sticker covering their face
    Away from the keyboard.↗
    OFFLINE
    FOR A
    MINUTE.

    04 The person behind it

    I’ve been taking
    things apart since
    I was a kid.

    I started programming at ten, on my first laptop, trying to figure out a game I’d seen on YouTube. That habit stuck.

    My career didn’t start with a software engineering title. It started with helping people get their technology to work. Eventually, I started building the tools I kept wishing were there.

    I’m still doing that. Sometimes it’s an enterprise integration. Sometimes it’s a product of my own. I like understanding the problem well enough to make something useful.

    More about my background
    Have something in mind?

    LET’S TALK.

    About a problem, a product, or something you’re building.

    Find me on LinkedIn ↗