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John Ndigirigi
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John Ndigirigi

Full-stack & AI Engineer · Nairobi, working remotely worldwide.

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© 2026 John Ndigirigi

Built with React + Vite + Tailwind

Available for remote roles and contracts

Portrait of John Ndigirigi

John Ndigirigi

Full-stack & AI Engineer

I ship production web, mobile and SaaS products end to end, and build AI features that are safe to put in front of customers.

Now building QuoteKamili, an AI quoting product for trade suppliers. Previously led engineering at Sociale and mobile development on a Toptal client team.

Book a 30-minute call (opens in a new tab)See my work

Nairobi, UTC+3 · Full overlap with UK and EU hours · 4+ hours with US Eastern

Shipped with

  • Toptal
  • QuoteKamili
  • Sociale
  • DirectEd (UK)
  • Blocktrust (Germany)
  • DIGN

Now building · Founder & Lead Engineer

QuoteKamili

AI quoting for trade and industrial suppliers, from electrical and plumbing to building materials and metals. It turns emails, PDFs, scans and photos of handwritten lists into priced quotes in under a minute.

  • The AI only reads the request. Prices, fees, totals and unit conversions run in tested code, and supplier pricing never goes to a model.
  • Every quote line links back to its place in the source document, and a rep approves each quote before it reaches a customer.
  • Multi-tenant on AWS (ECS Fargate, RDS PostgreSQL with pgvector, CDK), with one React codebase on web, iOS, Android and desktop.
Read the case studyquotekamili.com (opens in a new tab)
QuoteKamili: "Fast, accurate quotes from any customer request", with a faxed order turned into a priced quote and a delivery charge added.

Selected work

All projects →
Sociale's landing page beside a cooperative dashboard with members, deposits and recent transactions.

Lead Developer · 2025–2026

Sociale

Multi-tenant platform for savings groups and credit unions across Africa. I led the team and the architecture: PostgreSQL row-level security isolates every cooperative's data without per-tenant infrastructure. Shipped LLM agents for board reporting, risk analysis and a multilingual member assistant.

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iOS · Android

ParentsChildrenCoaches

Expo React Native · RevenueCat

Mobile Lead, Toptal client · 2026

Children's digital wellness app

iOS and Android app for parents, children and coaches. Led mobile in an 8-person team, built sign-in (one-time passcodes, Apple, Google) and RevenueCat subscriptions, and set up the release pipeline to TestFlight and Google Play.

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Notamperdata's landing page: verify research data with blockchain.

Lead Developer & Maintainer · 2024–2026

Notamperdata

Open-source Google Workspace add-on, published on the Marketplace, that gives research data a tamper-evident audit trail. Only SHA-256 hashes leave Google's infrastructure.

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How I build with AI

I use AI agents to ship faster, and I keep AI inside products on a short leash. Both follow one rule: nothing is trusted until it is checked.

  1. 01

    Spec first, small slices.

    Every feature starts as a written spec with acceptance criteria. Agents, mainly Claude Code and often several in parallel, build it in small, reviewable slices.

  2. 02

    Verified, not trusted.

    Agent-written code passes the same gates as mine: type checks, dependency boundaries, property-based tests, real-browser and accessibility tests.

  3. 03

    AI reads, code decides.

    In products, models read and suggest. Tested code handles money and data, and a person approves anything customer-facing.

  4. 04

    A maintained agent setup.

    A reusable configuration of conventions, checks and review rules, connected to tools over MCP and updated as models change.

Ways to work with me

  • Build your product

    What you get
    Spec to launch: web, mobile and back end on one TypeScript stack, deployed on AWS
    Good fit
    An MVP or v1 that has to be production-grade

  • Add AI to your product

    What you get
    Document extraction, agents or RAG, with human review and source tracing built in
    Good fit
    A SaaS that wants AI features without the risk

  • Join or lead your team

    What you get
    Full-time remote or long-term contract; I have led web and mobile teams and set up CI/CD
    Good fit
    A team that needs a senior full-stack or mobile lead

Hire me directly or through Toptal.

Experience

Full background →
  1. QuoteKamiliFounder & Lead EngineerSep 2026 – Present
  2. ToptalFull-stack & AI Engineer (Freelance)Jun 2026 – Present
  3. SocialeLead DeveloperMar 2025 – May 2026
  4. DIGNIdentity Solutions EngineerJan – May 2026
  5. Blocktrust (Germany)Software EngineerMar 2024 – Mar 2025
  6. DirectEd Development Foundation (UK)Software EngineerDec 2022 – Mar 2024

Writing

All posts →

Jul 2026 · 7 min read

Building Production AI Agent Workflows with LangGraph.js: Lessons from the Field

Building an AI agent that works in a demo is easy. Building one that handles edge cases, recovers from failures, and maintains state across sessions is not. Lessons from shipping LangGraph.js agent workflows across a cooperative finance platform and a WhatsApp-native farm operations system.

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Jun 2026 · 6 min read

AI Credit Scoring Without the Black Box: Explainable Loan Risk for Cooperative Finance

Standard credit scoring models fail for thin-file borrowers with no bureau history. How we built an interpretable AI credit scoring system for cooperative finance using domain-specific features, gradient boosting, and LLM-generated explanations: where the committee can always see why.

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May 2026 · 6 min read

WhatsApp as a Production API Surface: Building AI-Native Apps for Low-Bandwidth Markets

Most products assume the interface is a screen. In much of sub-Saharan Africa, the interface that reaches the most people is WhatsApp. What it means architecturally to build AI-native products with WhatsApp as the primary surface: not a notification channel, but the actual product.

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Have a product to build or a team to join?

Tell me what you're working on. I reply within one working day.

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Nairobi, UTC+3 · Full overlap with UK and EU hours · 4+ hours with US Eastern

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