TEEI in Practice

TEEI in Practice

Impact, Partnerships & Technology

Research & Engineering

Research and engineering in learning, language and impact measurement. Explore architectures, language technology, benchmarks, evaluation methods and experiments, including how TEEI develops and tests its tools and what others can learn from the work.

Cloudflare Workers

Start here

How TEEI Runs Its Platforms on Cloudflare Workers

TEEI's website, TEEI Language, TEEI Mentorship and Evenhall run on Cloudflare Workers. This is how, with what broke and what we measured.

Read the article

Diagram of one Cloudflare account running the TEEI website, TEEI Language, TEEI Mentorship and Skills Academy, Evenhall and admin as Workers, with the services each one binds
  1. Durable Objects for Rings, SQL for Outcomes
  2. Durable Object alarms: stale decisions, moving deadlines
  3. We Mask Country Pairs Before Storing Live Events
  4. Cloudflare Workers: Shorter Trips, Fewer Trips
  5. Why We Freeze Email Payloads on Cloudflare Queues
  6. What We Bypass with Cloudflare Service Bindings
  7. One Cron Owner, Still Duplicate Ticks
  8. Why We Keep libSQL Clients Inside Each Worker Request
  9. How We Compare Builds and Verify a Worker Release
  10. Counting to 128 Before We Add One Worker Secret
  11. Pages to Workers: The Defaults We Had to Rebuild
  12. Why our certificate repairs need a new R2 address
  13. How We Join React Router Errors Across Browser and Worker

React Router 8

Engineering note

Two Workers, One React Router 8 App: Decide at the Boundary

We build two Workers from one React Router app, pass programme identity through typed context, and use stored rows for scheduled work.

  1. How We Share One Session Lookup Across React Router Loaders
  2. One Nonce, Two Inputs: Fixing React Router Streaming
  3. Typed Pings and Failure as Data in React Router
  4. Why We Broke a React Router Build With an Unused Export
  5. Old Tabs, New Workers: A Guarded Reload

Astro on Workers

Engineering note

Building a Live Homepage with Astro and Cloudflare Workers

A local browser experiment found two ordering bugs in our activity line. We follow the handoffs between Astro, Workers and the visible text.

  1. Astro Server Islands: Cache Age Is Not Data Age
  2. Why We Still Handle WebSockets Before Astro
  3. Worker First Is Not Middleware First: Astro on Cloudflare
  4. We Pruned 12,115 Astro Redirect Pages from Our Build
  5. Astro on Workers: the bugs between build and runtime
  6. Keeping Astro Content, Sitemaps and Search in Sync

AWS

Engineering note

What TEEI Runs on AWS

The AWS services that carry TEEI's free programmes, measured: Chime video, Bedrock checks and who decides, monitoring, and how releases are verified.

Diagram of the TEEI programmes on one Amazon Chime SDK layer, with meeting events flowing on to programme history and, nightly, to Evenhall
  1. How TEEI Turns Amazon Chime SDK Events into Verified Hours

Algolia

Engineering note

How Algolia Powers Multilingual Search at TEEI

With support from Algolia for Open Source, TEEI helps people find help answers and job titles in four languages, even when the spelling is imperfect.

Two phones showing TEEI Mentorship in Ukrainian: the job picker, where програміст lists software developer first, and the help centre, where не працює камера finds the answer about a camera that is not working.

ElevenLabs

Engineering note

How Practice Companion Uses ElevenLabs

How we run Say it live on the ElevenLabs Speech Engine, with our own rules deciding each reply, and voice each Listen dialogue once for streaming from R2.

Dark band with the TEEI and ElevenLabs marks, the headline Real-life conversations, rehearsed out loud, and the line Both rooms use ElevenLabs, in two different ways. Beside it, two Practice Companion phone screens: the Say it room in the scenario The doctor, mid-conversation with a clinic receptionist and a You could say prompt, labelled Say it, live, and the Listen room in Calling the clinic, with a recorded caller and the first comprehension question, labelled Listen, recorded once.
  1. Inside Practice Companion: Rooms, Evidence and Level
  2. How Learners Get Sentence Feedback in Practice Companion

Take part

Teach what you know. Bring your team.

Sample sessions.

Skills Academy

Teach your technology in Skills Academy

Your engineers, educators and specialists teach the tools and methods they know. Teaching your own product is welcome when the session helps people learn to use it well.

  • An hour at a time, on TEEI’s own platform, to people retraining toward your field.
  • No lesson plans, no grading: the format carries the structure.
  • Participants’ details are never shared with your employer.

Teach in Skills Academy Explore Skills Academy

Sample data.

Corporate volunteering

Your employees become the volunteers in programmes TEEI already runs.

Organise participation. Leave programme delivery to TEEI. It is free, with no licence and no limit on people: we are a nonprofit, and we would rather have your people in the programmes than in a procurement cycle.

  • TEEI Language An hour of conversation with one adult learner, in a language your colleague already speaks.
  • TEEI Mentorship Professional experience brought to one person’s next career decision: a CV, an interview, a project, what to learn next.
  • Skills Academy A live class, workshop, clinic or expert Q&A on a skill your team uses, leading into courses and learning paths.

Explore corporate volunteering Start the conversation

The work behind this Build with TEEIRead about TEEI research

All articles in Research & Engineering

Cloudflare Workers

  1. How TEEI Runs Its Platforms on Cloudflare Workers Start here
  2. Durable Objects for Rings, SQL for Outcomes
  3. Durable Object alarms: stale decisions, moving deadlines
  4. We Mask Country Pairs Before Storing Live Events
  5. Cloudflare Workers: Shorter Trips, Fewer Trips
  6. Why We Freeze Email Payloads on Cloudflare Queues
  7. What We Bypass with Cloudflare Service Bindings
  8. One Cron Owner, Still Duplicate Ticks
  9. Why We Keep libSQL Clients Inside Each Worker Request
  10. How We Compare Builds and Verify a Worker Release
  11. Counting to 128 Before We Add One Worker Secret
  12. Pages to Workers: The Defaults We Had to Rebuild
  13. Why our certificate repairs need a new R2 address
  14. How We Join React Router Errors Across Browser and Worker

React Router 8

  1. Two Workers, One React Router 8 App: Decide at the Boundary
  2. How We Share One Session Lookup Across React Router Loaders
  3. One Nonce, Two Inputs: Fixing React Router Streaming
  4. Typed Pings and Failure as Data in React Router
  5. Why We Broke a React Router Build With an Unused Export
  6. Old Tabs, New Workers: A Guarded Reload

Astro on Workers

  1. Building a Live Homepage with Astro and Cloudflare Workers
  2. Astro Server Islands: Cache Age Is Not Data Age
  3. Why We Still Handle WebSockets Before Astro
  4. Worker First Is Not Middleware First: Astro on Cloudflare
  5. We Pruned 12,115 Astro Redirect Pages from Our Build
  6. Astro on Workers: the bugs between build and runtime
  7. Keeping Astro Content, Sitemaps and Search in Sync

AWS

  1. What TEEI Runs on AWS
  2. How TEEI Turns Amazon Chime SDK Events into Verified Hours

Algolia

  1. How Algolia Powers Multilingual Search at TEEI

ElevenLabs

  1. How Practice Companion Uses ElevenLabs
  2. Inside Practice Companion: Rooms, Evidence and Level
  3. How Learners Get Sentence Feedback in Practice Companion

Engineering note

  1. From an Email to a Real Conversation: How TEEI Builds on Resend
  2. How Project Galileo Protects TEEI’s Platforms
  3. How Evenhall Drafts Company Reports with the Vercel AI SDK
  4. When the Website Is Up but the Signup Flow Is Broken

Research

  1. AI Writing-Level Estimate: What TEEI Tested and Learned

Guide

  1. How TEEI Works: One Platform, Many Programmes

Impact, Partnerships & Technology

For people volunteering, building partnerships and reporting their work