Companies keeping their job boards up to date

Many job boards show a timestamp indicating when the job was posted (including jobs on Taro). Use this to find jobs in the last 2-3 days. Anything above a week is quite old and will already have had tons of applicants.

The quality of the job board also matters a lot. For larger platforms, you'll come across recruiting agencies who are further removed from the actual job, and you'll have "ghost" jobs from larger companies that are not being monitored.

It is almost impossible to keep jobs up to date. Often times the recruiter/hiring manager will forget to take down a job posting after it's been filled. Sometimes the position is 90% of the way to being filled (i.e. an offer has been extended), but they're leaving up the job posting just in case the candidate rejects. Sometimes the recruiter behind the job posting literally got laid off, and the headcount was also shut down (this unfortunately happens quite a lot in the current market).

As Rahul mentioned, heavily prioritize the fresh jobs, those posted within the last 3 days. For top companies (e.g. FAANG), you want to apply within the first 24 hours as those companies can easily get 500+ applicants within the 1st day - I remember a Netflix SW1 position got 2,500+ applicants within 24 hours!

After you go through the jobs that are younger than 3 days, you can apply to others if you have time. If a job has been up for 1 month+, it's almost certainly dead.

I hope this helps as well: "What are the best websites for applying for tech jobs?"