Of the ten postings, Synthetic Minds (YC S18) is by far the most revealing — not because of what it says, but because of what it doesn't. There's no stack listed. No "React/Node/AWS." No perks section. Just: "we are building program synthesizers... a compiler that takes code and translates it to theorem proving." That is a deliberate filter.

The tech stack (inferred): Program synthesis via theorem proving points to a very specific toolchain — likely Coq, Lean, Isabelle, or Z3/SMT solvers, with a functional host language (OCaml, Haskell, or increasingly Rust). The link to their 2019 conference program confirms the crowd: PL researchers, formal methods people, SMT hackers. This isn't a stack you learn from a bootcamp; it's a stack you learn in a PhD program.

What the posting reveals about stage and direction:

• YC S18 + still hiring "all engineering" in 2020 — nearly two years in and the team is still small enough that every hire is generalist. Research-heavy startups burn slowly; this is consistent with a Series A runway funding deep R&D, not a growth-mode play.
• "$120k+" as a floor — modest for the Bay Area, aggressive for a remote-considered role, which suggests they're competing on problem rather than comp. That works when the candidate pool is PhDs who care more about the substrate than the salary.
• "Compiler that translates code to theorem proving" — this framing is the giveaway. They're betting that LLM-style statistical code generation has a ceiling, and that verified/synthesized code is the long-term winner in high-assurance domains (security, finance, critical infra).

Skills and trends highlighted: Formal verification is quietly having a moment — AWS's use of TLA+, Microsoft's Dafny, the growing Lean 4 community. Synthetic Minds is a bet that program synthesis becomes commercially viable as compute gets cheaper.

Green flags: Technical honesty (they describe the actual problem, not buzzwords), remote-friendly for a research shop, transparent salary floor.

Red flags: The posting is truncated mid-sentence — small operational sloppiness. No mention of customers, revenue, or applied domains suggests they may still be pre-product-market-fit two years post-YC. "All engineering team" with "including PhDs" can mean brilliant, but also can mean allergic to shipping.