Simon Willison’s Weblog

Reinforcement Learning with Prediction-Based Rewards (via) Fascinating result: by teaching a reinforcement learning agent that plays video games to optimize for “unfamiliar states”—states where it cannot predict what will happen next—the agent does a much better job of playing some games. “... for the first time exceeds average human performance on Montezuma’s Revenge. RND achieves state-of-the-art performance, periodically finds all 24 rooms and solves the first level without using demonstrations or having access to the underlying state of the game.” # 31st October 2018, 11:51 pm

October 21 post-incident analysis (via) Legitimately fascinating post-mortem by GitHub. They run database masters in multiple data centers with raft for leader election... but when they had an unexpected network split between east and west coast they ended up with several seconds of write that had not been correctly replicated. Cleaning up the resulting mess took the best part of 24 hours! Distributed systems are hard. # 31st October 2018, 8:50 pm

Making Sense of React Hooks (via) Dan Abramov provides the most comprehensive justification I’ve seen so far for the new React hooks API. # 31st October 2018, 4:26 am

This Is How We Radicalized The World (via) Don’t be put off by the click-baity title: this article by Ryan Broderick is absolutely worth your time. Ryan has been traveling the world covering the global rise of populism, which has been driven in a great part by new patterns of social media usage and distrust of the news media. Ryan ties together stories from a bunch of different countries over the last few years and make a compelling case that we need to come to terms with social media radicalization as a global problem and figure out how to respond to it and deal with the fallout. # 31st October 2018, 1:11 am

matthewp/haunted: React’s Hooks API implemented for web components (via) It’s been fascinating over the past few days watching various frontend web stacks start playing with the new ideas introduced by the proposed React hooks API. lit-html is one of my favourite React alternatives—it’s built on web components and makes really clever use of ES6 template literals (in place of React’s JSX, which requires an additional compilation step). With Haunted Matthew Phillips explores the combination of lit-html, web components and hooks-style state management. # 31st October 2018, 1:04 am

python-twitter/get_access_token.py. Creating an OAuth token for accessing a specific Twitter account is way harder than it needs to be. I was about to write my own command-line script for doing this using PIN-based authentication (where you pop open a browser showing the Twitter login flow, then get a PIN number at the end which you paste back into your script) when I discovered that the python-twitter library already ships with a script to do exactly that. Just run “python get_access_token.py”, paste in your app’s consumer key and secret, follow a link, enter the resulting PIN and the script will spit out the consumer_key / consumer_secret / access_token_key / access_token_secret combo you need to start using the Twitter API. # 28th October 2018, 5:25 pm

Introduction to Redis Streams. Redis 5.0 is out, introducing the first new Redis data type in several years: streams, a Kafka-like mechanism for implementing a replayable event stream that can be read by many different subscribers. # 18th October 2018, 8:35 am

github-debug.com (via) This is a neat trick: GitHub have a dedicated site for their support engineers to send you to if you can’t connect to them. The site tests download speeds from their various domains and then lets you click a button to have GitHub run a traceroute/ping from their servers to your detected IP address and output the results (use devtools to spy on their API method for doing this). Then you can paste the results into a message to their support team. Turns out fastly-debug.com and dropbox-debug.com implement a similar pattern for those services as well. # 10th October 2018, 7:32 pm