In 2019, how do you validate your ideas before writing code?

A few days ago, one Silicon Valley founder I follow on Twitter (Suhail) posted a million-dollar question:

“What is the best test you've heard of to gauge how much people will care about a product before writing a single line of code?”

If you’ve ever worked at a startup or ventured to build one, I am sure this exact question must have crossed your mind: How do you know people will buy your product? There’s no one golden hack but below are some interesting responses from other founders:

1) “We used Dropbox Paper to MVP. It helped validate some assumptions and inspired ideas before we started building.” — Ryan Hoover, Product Hunt

2) “Pretend it's a real thing, take payment. Say "oops you're early but secured X price. Will refund if you want but would love your feedback" — Ben Tossell, MakerPad & NewCo

3) “For b2b/enterprise the best indicator is that potential customers have already built a partial version of the solution out of duct tape, baling wire, and Excel. Which they are desperate to replace.” — Richard Tibbetts

4) “Create a landing page / explainer video and sell it, then refund. No amount of “would you buy this” compares to someone pulling out their wallet and actually going through the motions to pay you for that thing. “ — Austin Mullins

5) Process that’s worked for us on various products (b2b and b2c):

a) Build a small email list of 500+ around the topic

b) Presale to focus groups

c) Stop and build once 10%+ buy — Bryan Harris

6) “High fidelity mockups + trying to sign a paid contract (need both together) “ —Zach Weinberg

7) “Deep frustration (almost anger) toward reliability and ease of use of existing offering (e.g., web conferencing, enterprise chat) - Ability for suggested offering to be able to quantify ROI of Board-tracked KPI (revenue, usage, churn)” — Nimesh

8) “Give customers a contract and see if they will sign (don’t let them actually sign tho) “ — Kevin Gibbon

9) “2 good pre-code MVPs are Buffer (SEM only) & Dropbox (video only). I like to ask pre-PMF startups to talk to N prospects & M industry people before embarking on risky journeys. In B2C: N=40, M=10. In B2B: N=20, M=5. Pre or post code isn't relevant. Removing risk is removing risk. “ — Itai Damti

What do you think? What is a method that works for you?

Check out the full thread here, it is definitely worth reflecting on.