AngelList works almost as you'd expect from a dating app. You can click "Interested" in a position or company. If the company does the same with you, an introduction email will be sent to both parties.
This helps save time applying for jobs as you know who's interested.
Every job post must include a salary range for the position, which saves you from wasting time applying to positions that aren't offering the salary you're looking for.
Currently there are a couple hundred remote jobs listed (in total, not specific to devops). While that is still a good number to look through, it's nothing compared to many of the remote-specific job boards.
Some job boards will allow a position to be tagged with "remote" if the job only includes some work from home days. Stack Overflow requires that candidates be allowed to work entirely remote for the remote tag to be added.
There is usually around a couple hundred remote positions listed at any given time (all jobs, not specific to just one type), which isn't a lot compared to many remote-specific boards.
Where many of the current remote job boards are specifically for employees looking to apply to positions, reddit is a good place to post "for hire" ads and allow the employers to contact you.
The cost to post a job on We Work Remotely is $200/30 days. Being such an investment for the company insures that all job posts are from serious employers.
We Work Remotely is fairly quiet, with often only one or two new job posts a day. This is likely due to the $200/month cost for employers to post the job ad. There is usually no more than 10 jobs listed under the "Devops and Sysadmin" category.
The payment of remote developers is very high. If you want only quality work then only go with codersera. Because they charge a good amount for a quality product.