Hacker News on 31 January 2019

• Apple blocks Google from running its internal iOS apps
• Facebook Referred to Kids as Young as Five as “Whales” for Its Monetized Games
• U.S. Changes Visa Process for High-Skilled Workers
• Interactive SICP
• Product-building articles by PMs at major tech companies
• The UAE’s secret hacking team of U.S. mercenaries
• Write tests. Not too many. Mostly integration (2017)
• Skirting U.S. sanctions, Europeans launch trade mechanism for Iran
• Apple leaves Facebook offices in disarray after revoking app permissions
• Ask HN: Top three questions for a startup before accepting a job offer?