Python or any equivalent Job Posting Crawler

I need a small-footprint script that periodically scans the HR/Careers pages of a set of IT-sector companies that run their own data centres. Whenever a fresh vacancy mentioning “Linux administration” (or close variants such as “Linux admin”, “Systems Administrator – Linux” etc.) appears, the program should recognise that it has not been seen in any earlier run, capture the full job description, and send it to me by email.

Key requirements
• Language: Python is preferred, but another easily maintained language is acceptable if it delivers the same automation and accuracy.
• Input flexibility: I will pass the list of company URLs in a simple text or CSV file, so adding or removing a target site never needs code edits.
• Content capture: Crawl only the HR/Careers section of each site, follow any pagination there, and ignore news, press releases, or other areas.
• Keyword logic: Trigger only when the posting clearly relates to Linux administration; avoid false positives from generic IT or Windows roles.
• Change tracking: Maintain a lightweight local store (JSON, SQLite, or similar) so that previously found jobs are not emailed again.
• Email alert: Send a concise message containing the job title, URL, posting date (if available), and the extracted description. A simple SMTP configuration file is enough—no need for a full mail server build.
• Scheduling: It should be runnable via cron / Task Scheduler; a 10-15 minute crawl cycle is fine as long as no single run overlaps the next.

Deliverables
1. Clean, well-commented source code.
2. A short README describing dependencies (e.g., requests, BeautifulSoup, Selenium if needed for JavaScript sites) and setup steps.
3. Example configuration files for the site list and SMTP settings.
4. A brief video or screenshot walkthrough proving the alert fires on a test posting.

I will consider the task complete once I can plug in three live company URLs, run the script unattended for a day, and consistently receive email whenever their careers page publishes a Linux administration role while ignoring everything else.