> Markdown version of [/videos/world-congress-2021?page=5](https://www.wearedevelopers.com/videos/world-congress-2021?page=5). Every page supports `.md` or `Accept: text/markdown`. Links point to the HTML versions so they work for humans too. Agent guide: [/agents.md](https://www.wearedevelopers.com/agents.md). --- # Videos 2123 videos · 23049 moments · 1194.7 hours of content ## World Congress 2021 videos ### A journey of a long list in React Virtual scrolling builds a bridge just ahead of users and dismantles it behind them. Master this technique and intersection observers to flawlessly render massive lists in React. - **Speakers:** Adam Klein - **Event:** World Congress 2021 - **Published:** June 29, 2021 - **Duration:** 43:08 - [Watch](https://www.wearedevelopers.com/videos/203-a-journey-of-a-long-list-in-react) ### 40 Minutes to Build a Serverless COVID-19 REST and GraphQL APIs Tired of wrestling with messy CSVs and rigid database migrations? Learn how to build resilient, serverless REST and GraphQL APIs in just 40 minutes using MongoDB Atlas. - **Speakers:** Maxime Beugnet - **Event:** World Congress 2021 - **Published:** June 29, 2021 - **Duration:** 47:16 - [Watch](https://www.wearedevelopers.com/videos/208-40-minutes-to-build-a-serverless-covid-19-rest-and-graphql-apis) ### P2P networks in Blockchain How do unstructured P2P networks survive constant node churn and eclipse attacks? Discover how the Lisk SDK secures custom JavaScript blockchains using advanced peer management. - **Speakers:** Ishan Tiwari - **Event:** World Congress 2021 - **Published:** June 29, 2021 - **Duration:** 42:35 - [Watch](https://www.wearedevelopers.com/videos/209-p2p-networks-in-blockchain) ### pytest: Simple, rapid and fun testing with Python Ditch verbose unittest boilerplate for plain Python assertions. Pytest transforms your workflow with modular fixtures and a massive plugin ecosystem for scalable, maintainable test automation. - **Speakers:** Florian Bruhin - **Event:** World Congress 2021 - **Published:** June 29, 2021 - **Duration:** 47:19 - [Watch](https://www.wearedevelopers.com/videos/213-pytest-simple-rapid-and-fun-testing-with-python) ### Rapid GraphQL API Development with PostGraphile Stop manually writing repetitive GraphQL boilerplate. Learn how PostGraphile instantly turns your PostgreSQL schema into a lightning-fast, production-ready API while solving the dreaded N+1 query problem. - **Speakers:** Ruwan Xaviour Fernando - **Event:** World Congress 2021 - **Published:** June 29, 2021 - **Duration:** 46:47 - [Watch](https://www.wearedevelopers.com/videos/214-rapid-graphql-api-development-with-postgraphile) ### Rethinking web application design for fastest possible time to interactive Why download massive JavaScript bundles just to attach event listeners? Learn how Qwik's resumable architecture eliminates client-side hydration to achieve near-instant page interactivity. - **Speakers:** Misko Hevery - **Event:** World Congress 2021 - **Published:** June 29, 2021 - **Duration:** 44:35 - [Watch](https://www.wearedevelopers.com/videos/215-rethinking-web-application-design-for-fastest-possible-time-to-interactive) ### SEO in Angular? No big deal with SSR and Angular Universal Stop losing organic traffic to unreadable single-page applications. Master Angular Universal to serve pre-rendered, bot-friendly HTML that instantly boosts your SEO ranking and first contentful paint speeds. - **Speakers:** Martina Kraus - **Event:** World Congress 2021 - **Published:** June 29, 2021 - **Duration:** 44:00 - [Watch](https://www.wearedevelopers.com/videos/217-seo-in-angular-no-big-deal-with-ssr-and-angular-universal) ### Seven Myths, Three Reasons, One Goal Blindly layering a REST API over a legacy database creates a fragile distributed monolith. Learn to leverage use-case-driven architectures to modernize systems without triggering expensive, boil-the-ocean rewrites. - **Speakers:** Stefan Priebsch - **Event:** World Congress 2021 - **Published:** June 29, 2021 - **Duration:** 46:48 - [Watch](https://www.wearedevelopers.com/videos/218-seven-myths-three-reasons-one-goal) ### Software stack under and over the hood of the fastest accelerating car in the world How do you code the world's fastest electric hypercar? Dive into the Rimac Nevera's complex software stack, featuring 70 interconnected ECUs, bare-metal C, and high-performance Kafka pipelines. - **Speakers:** Denis Grahovac - **Event:** World Congress 2021 - **Published:** June 29, 2021 - **Duration:** 58:48 - [Watch](https://www.wearedevelopers.com/videos/221-software-stack-under-and-over-the-hood-of-the-fastest-accelerating-car-in-the-world) ### The Story of Games Brenda Romero exposes video games as profound therapeutic tools that can outperform morphine. Learn how diverse developers are coding the future of interactive storytelling. - **Speakers:** Brenda Romero - **Event:** World Congress 2021 - **Published:** June 29, 2021 - **Duration:** 56:37 - [Watch](https://www.wearedevelopers.com/videos/226-the-story-of-games) ### Developer’s Perspective: Overview of the Tezos Blockchain Ecosystem How do you build secure, upgradeable decentralized apps without risking a protocol fork? Master the Tezos ecosystem, from formal verification to developer-friendly tooling like SmartPy and Ligo. - **Speakers:** Arthur Breitman - **Event:** World Congress 2021 - **Published:** June 29, 2021 - **Duration:** 40:28 - [Watch](https://www.wearedevelopers.com/videos/237-developer-s-perspective-overview-of-the-tezos-blockchain-ecosystem) ### Deployed ML models need your feedback too Standard infrastructure tracking won't catch concept drift in your ML models. Learn how to build continuous feedback loops that directly link ground-truth performance to business OKRs. - **Speakers:** David Mosen - **Event:** World Congress 2021 - **Published:** June 28, 2021 - **Duration:** 37:24 - [Watch](https://www.wearedevelopers.com/videos/161-deployed-ml-models-need-your-feedback-too) [Next page](https://www.wearedevelopers.com/videos/world-congress-2021?page=6)