John Ndigirigi

Skills

Languages

• TypeScript
• JavaScript
• Python
• SQL
• C#

Front end and mobile

• React
• Next.js
• React Native
• Expo
• Capacitor
• Tauri
• Tailwind CSS
• React Aria

Back end and data

• Node.js
• Express
• FastAPI
• PostgreSQL (row-level security, pgvector)
• MongoDB
• Prisma
• Redis
• REST
• GraphQL

AI

• LLM applications
• AI agents and agentic workflows
• Document extraction
• RAG
• LangGraph
• OpenAI and Anthropic APIs
• Claude Code
• Cursor
• GitHub Copilot
• Model Context Protocol (MCP)

Testing and quality

• Vitest
• Playwright
• Jest
• fast-check (property-based testing)
• axe-core (accessibility)

Cloud and delivery

• AWS (ECS Fargate, RDS, CDK)
• GCP
• Docker
• GitHub Actions
• CI/CD
• Linux

Identity and Web3

• KERI
• ACDC
• W3C Verifiable Credentials
• DIDs
• Cardano smart contracts (Aiken)

Experience

1. Founder & Lead Engineer

   QuoteKamiliCurrent

   Sep 2026 – Present · Remote

   B2B SaaS for trade and industrial suppliers in the UK, Ireland and the US, from electrical, plumbing and HVAC to industrial and MRO, hardware, building materials and metals, turning requests for quotes into complete, priced quotes.

   • Built an AI pipeline that reads quote requests in any format (emails, PDFs, faxes, scans, spreadsheets, photos of handwritten lists, bills of quantities), matches each line to the supplier's catalogue and returns a complete quote in under a minute instead of hours of retyping.
   • Kept AI away from the money: it only reads the request, while prices, fees, totals and unit conversions run in tested code from the supplier's own price lists and fee rules, and supplier pricing is never sent to a model. Every quote line links to its place in the source document, and a rep approves each quote before it goes to a customer or the ERP.
   • Architected a multi-tenant platform on AWS (ECS Fargate, RDS PostgreSQL with pgvector, CDK) with row-level security in the database and idempotent background jobs, so retries never create duplicate quotes or charges.
   • Test pricing and credit rules with property-based tests (fast-check) and run UI tests in real Chromium, WebKit and Firefox with Vitest, Playwright and axe-core, and ship one React codebase to web, iOS and Android (Capacitor) and desktop (Tauri).

2. Full-stack & AI Engineer (Freelance)

   ToptalCurrent

   Jun 2026 – Present · Remote

   Accepted into Toptal's freelance network after its multi-stage technical screening.

   • Mobile Lead on a children's digital wellness app (Toptal client), Jul – Aug 2026: led mobile development in an 8-person team spanning backend, QA, DevOps and mobile, delivering separate iOS and Android experiences for parents, children and coaches in Expo React Native and TypeScript.
   • Built secure sign-in (one-time passcodes, Sign in with Apple, Sign in with Google) and in-app subscriptions with RevenueCat, gating paid features by entitlement.
   • Established the release pipeline: automated linting, type checks, tests and builds, with submission to TestFlight and Google Play through GitHub Actions and EAS.

3. Lead Developer

   Sociale

   Mar 2025 – May 2026 · Remote

   Multi-tenant platform for savings groups and credit unions across Africa (SACCOs, chamas, stokvels and ROSCAs).

   • Led a team and architected the platform: a Node.js REST API on PostgreSQL with row-level security, giving every cooperative fully isolated data without per-tenant infrastructure, plus a React admin dashboard and a React Native member app.
   • Integrated an AI credit-scoring engine and built LLM agents for board reporting, risk analysis and a multilingual member assistant, bringing agentic workflows into production financial software.
   • Built portable Financial Passports that turn a member's verified contribution and repayment history into credentials they can take between institutions, and an on-chain cooperative treasury with multi-signature withdrawals.

4. Identity Solutions Engineer

   DIGN

   Jan – May 2026 · Remote (contract)

   • Built integration and demo sites for enterprise partners on a KERI-based identity platform, covering supply chain provenance and onboarding scenarios against live AWS-hosted agents.
   • Wrote the partner integration documentation and researched interoperability with the vLEI and GLEIF ecosystem.

5. Lead Developer & Maintainer

   Notamperdata

   Mar 2024 – Feb 2026 · Remote (part-time) · Open source

   • Built and maintained an open-source Google Workspace add-on, published on the Workspace Marketplace, with a Next.js verification app that gives research data a tamper-evident audit trail.
   • Designed for privacy: only SHA-256 hashes leave Google's infrastructure, anchored on the Cardano blockchain.

6. Software Engineer

   Blocktrust

   Mar 2024 – Mar 2025 · Germany (Remote)

   • Built a no-code workflow platform in C# and .NET that lets organisations compose credential issuance, KYC verification and sign-in flows without writing code.
   • Delivered a fully client-side credential builder and an endorsement system whose credentials expire automatically, preventing misuse of stale endorsements.

7. Software Engineer

   DirectEd Development Foundation

   Dec 2022 – Mar 2024 · UK (Remote)

   • Built full-stack MERN (MongoDB, Express, React, Node.js) applications, the core of DirectEd's platform work, and maintained the Python FastAPI back end on AWS that powered the main platform API.
   • Built internal tools, including a student onboarding platform based on self-sovereign identity.
   • Guided interns as they implemented several client projects, from design through delivery.
   • Joined as a tutor and intern before moving into engineering contracts.

Teaching and community

Education and certifications

• BSc Computer ScienceDedan Kimathi University of Technology
• Startup School (2026)Y Combinator
• Full Stack Development with ReactHKUST (Coursera)
• Cardano Blockchain Certified AssociateCardano Foundation