My response to the "compute is cheap" argument is always: Discord powers millions of concurrent live-chat and real-time-voice users from literally single (huge) VMs, using Elixir and Rust. Their revenue (relatively) sucks; its a powerhouse in communication because their revenue sucks (zero barrier to entry); and because their revenue sucks, they were forced to actually think critically about the technologies they use. They can't just throw more computers at the problem; and that limitation produced a far better product than, say, Slack.
Ok, smaller scale. You look at the latest Show HN SaaS product and wonder: "Why is there no free tier?" Free tiers are a classic in SaaS; it gets customers in the door, using your product, and you can upsell to higher tiers. Its all the same backend no matter the cost; but if your infrastructure & engineering costs are high, you may not be able to afford a generous free tier.
The days of the SaaS unicorn are behind us. Also; the days of Moore's Law (server-side at least) are quickly dwindling. This idea of "just throw more compute at the problem" needs to die a painful death. This week I consulted with a startup with something like $500k in ARR, spending $80k/year in cloud infrastructure. No free tier, all enterprise contracts, the most basic CRUD app you can imagine. A hundred NodeJS containers, every security service AWS offers enabled and logging terabytes of useless shit to an S3 bucket, autoscaling their database up to 100s of gigabytes in memory because "we don't have time to optimize". Sure; you also don't have time to not to. You're banking on some large enterprise contract to come through and buy another year; which will also add a few tens of thousands of more users to the platform, so you'll tweak the scale numbers up again, and again, and just keep praying one day you can cost optimize. Every day that goes by makes that harder, so you're also praying that maybe you can find more talent to do it, maybe we can grab some people from these layoffs, except what if we don't have the money to pay for talent just like the company that laid them off?
Python, JS, Big Cloud, had their time and were valuable during it; but today, startups need to think about cost optimization from day 1, and every cycle a CPU spends doing something is a cost. I'm not prescribing technologies; I'm just asking for more critical thinking, and not always operating with the "throw money at it" mindset. Maybe python makes sense; how can we deliver it with extremely low costs? Lambda? DigitalOcean? Can we integrate a more performance-oriented view into reviews? This part of the app experiences 10x the traffic the rest does; can we break that out into something far more efficient?
[1] https://discord.com/category/engineering