Technical difficulties at J. Crew and Lowe’s Companies kept IT and marketing teams busy on one of the most important shopping weekends of the year, especially as frustrated shoppers took to social media to complain about their experiences.

Lowe’s announced Friday afternoon via social media that its website was “down for maintenance.” These outages continued throughout the weekend, including on Cyber Monday, Nov. 26, according to the company’s Twitter feed.

Lowe’s tweeted at 1:58 pm on Nov. 23, “We apologize our website is down for maintenance. It will be available soon. If you need assistance with an order, please contact Lowe’s Customer Care at 1-800-445-6937 (Monday – Saturday, 7:00 a.m. – 2:00 a.m. Sunday 8:00 a.m. – 9:00 p.m.)”

Once the site was restored, the company followed up with a tweet that blamed increased customer traffic due to “our great Black Friday deals” for causing intermittent outages. It also said teams were “working diligently to restore the website to full functionality.”

When Cyber Monday shoppers didn’t fare much better, Lowe’s sent out a similar tweet, this time blaming outages on the high volume of customer traffic taking advantage “of our great Cyber Monday deals.”

Despite the updates, unhappy holiday shoppers fired back on Twitter.

For example, @nycjokerUS tweeted “@Lowes When do you expect to resolve Internal Server Error (500) on your website? Unable to access purchase history and track orders. Looks like the main page and placing orders issues were resolved on Black Friday. #outage”

J. Crew also suffered a technical snafu on Friday, one that kept shoppers from signing into the site and completing orders, according to CNBC. The specialty retailer also kept shoppers abreast via Twitter, posting…