Boost My Domain Authority Over 50

I'm looking to improve my website's domain authority to over 50. Currently, I've been focusing on backlink building and technical SEO, but I need an expert to take my efforts to the next level.

Key Techniques:
- Backlink Building: Primarily through guest posts, directory submissions and social media mentions.
- Technical SEO: Optimizing the site for better crawlability and indexability.

Ideal Skills:
- Proven experience with improving domain authority
- Expertise in backlink building strategies
- Proficient in Technical SEO
- Skilled in content creation for guest posts
- Knowledgeable in directory submission processes
- Experienced in leveraging social media for SEO purposes

Please provide your strategy and past success stories related to this project.