Amazon's supply chain ambitions were well-documented before COVID-19 gripped the world, but the e-commerce giant turbocharged its logistics expansion this year to catch up with elevated demand brought on by the pandemic.

Amazon already surpassed FedEx and nipped at UPS' heels in 2020 in terms of U.S. parcel deliveries, according to Pitney Bowes, and the company's logistics empire has grown even stronger since. Among the results: Amazon nearly doubled the size of its fulfillment network over 18 months, grew its freighter fleet and even launched a local delivery option for businesses.

The company still has work to do heading into 2022. Its one-day delivery service for Prime customers hasn't adjusted to the demand spike, and recent labor constraints have limited the efficiency of the company's supply chain.

Still, 2021 was a strong year for Amazon in its bid for complete control over its logistics operations. Here's a look back on some of the year's biggest Amazon stories.