SAN FRANCISCO \u2013 Facebook has a long list of challenges to address Tuesday when it kicks off its annual gathering for developers and partners to see the latest changes to its arsenal of hit apps. By most measures the company is almost invincible \u2013 each month at least 1.59 billion people use Facebook, more than a billion people use WhatsApp, 900 million use Messenger and 400 million are on Instagram. But the bigger Facebook becomes, the more it has to tackle nagging symptoms that could grow into full-blown diseases if left to fester.\u00a0\nThe social media juggernaut faces issues that very few companies have to endure. And let\u2019s face it: The bigger they are, the harder they fall. With that in mind, these are three of the biggest threats and tests facing the company this year.\u00a0\n1. Fuel social sharing\nContent is never in short supply on Facebook with 1.04 billion people using it every day. However, surfacing meaningful content for users and encouraging them to share those posts with others is an increasingly tall order. Users are posting more news and information from other sites on Facebook, but they haven\u2019t been as eager to share personal updates, according to The Information.\u00a0\n[Related: Facebook, Snapchat and the future of live video]\u00a0\nFirst-person story sharing declined 21 percent year over year as of mid-2015, according to the report. Facebook insists the level of sharing on its network remains strong and is on par with previous amounts, but it doesn\u2019t differentiate between someone sharing a post from The Onion or a personal recap of their weekend with photos, for example.\u00a0\nThe company has consistently added and tweaked features to increase sharing but it\u2019s taking on a new sense of purpose this year with its efforts in live video. Facebook might have a few other ideas up its sleeve this week to ward off the threat of today\u2019s more personal social platforms like Snapchat and other messaging apps.\u00a0\n2. Take humans out of customer care\u00a0\nFacebook Messenger is slated to be a central figure at F8. The company is expected to introduce chatbots and a live chat API for business to incorporate automated machine learning into sales and customer service, according to TechCrunch.\u00a0\nFacebook wants to help businesses take humans out of the business-to-consumer equation whenever it possibly can. By adding chatbots and artificial intelligence to Messenger, Facebook is introducing new modes of business for retailers and more reasons for users and businesses to regularly use the app.\u00a0\n3. Build a global case for live video at scale\u00a0\nFollowing a major overhaul of its live video service last week, Facebook is expected to showcase what it\u2019s been building and to continue carving out its place in the future of video. Some of the celebrities and public figures that Facebook is paying to use Facebook Live might even make an appearance at the event.\u00a0\n[Related: Facebook Live revamp hints at what\u2019s to come at F8]\u00a0\nGlitz and glamor will only go so far, however, because the true test comes when every user has the option to stream live video. If most of Facebook users take up the opportunity, the company will have its next hit feature in play and a huge stake in the next phase of social sharing.\u00a0\nFacebook has many challenges, but they aren\u2019t mutually exclusive. Facebook Live and artificial intelligence in Messenger could help the company dramatically reverse the decline in personal sharing while reinventing its namesake platform for another period of sustained growth. These milestones and others are expected to dominate the conversation and activity at F8.