I've been helping local brick-and-mortar stores get found for years, but the same principles work for software if you adapt them. Social media is a time sink for a solo dev - better to invest in passive discovery through structured data and directories.
Alternative spaces that drive organic traffic - beyond general directories like Product Hunt or AlternativeTo, try niche marketplaces that accept SaaS listings. Also, claim your Google Business Profile if your product has a physical address (even a co-working space). For pure software, focus on listing in curated SaaS directories that allow backlinks - places like G2, Capterra, or even industry-specific hubs. Each listing is a mini landing page, and Google crawls them.
SEO or programmatic discovery - write one long-form guide that solves a specific problem your software addresses, then use schema markup (FAQPage, HowTo) to get rich snippets. pair that with a programmatic landing page strategy: generate unique pages for each combination of keyword + location (if applicable) or use JS to dynamically serve content. For a bootstrapped startup, a single pillar post with internal links to tool-specific pages can bring passive traffic for years.
The one high-impact channel - I'd pick Google Search with a focus on 'best [software type] for [specific use case]' queries. You don't need daily posting, just one well-structured article with an embedded screencast and clear calls-to-action can outperform months of Twitter threads. Local SEO taught me that intent-driven traffic converts better than awareness-driven traffic every time.
Someone in the thread mentioned directory backlinks - they're not as strong as editorial links, but for a new product they signal relevance quickly. Don't overlook site speed and mobile usability, Google treats that as a ranking factor even for software reviews