Call: 20-min preliminary screen with James Page (Chief Product Officer) via Google Meet Role: Senior Software Engineer (React, Full-stack) Not a coding interview — this is a fit/interest conversation
River is a Bitcoin-only financial platform (~45 people, $70M raised). They deliberately reject being a "crypto exchange" — no altcoins, no memecoins, just Bitcoin. Founded 2019 in SF by Alex Leishman (ex-Airbnb security, Stanford CS).
Why they matter: In April 2025 they became the first Bitcoin-only exchange to publicly release financial statements as a private company. They hold 20,002 BTC against 19,660 BTC in client liabilities (>100% reserve). This transparency play is their moat — it's a direct post-FTX trust signal.
Key products:
- Zero-fee recurring Bitcoin purchases (DCA)
- 3.3% interest on cash (FDIC insured via Lead Bank), paid out in Bitcoin
- River Link — send Bitcoin via a shareable URL (no wallet address needed)
- Self-custody wallet
- River Lightning Services (RLS) — developer API for Lightning Network payments
- Managed mining service
- Private client ($100K+) and business accounts
Tech stack: React, Elixir, Postgres, Kubernetes. All custody and trading infrastructure built in-house (no third-party custodians). SOC 1 & 2 Type II certified.
- Title: Chief Product Officer
- Background: Product manager at Pinterest and Meta, both in AdTech
- Education: BA, American University
- Style: Data-driven product thinker coming from growth/monetization world, now applying that to consumer Bitcoin products
- He leads product strategy, product management, and design
- He also writes about cryptocurrency (jamespagewrites.com)
Read: He's the CPO doing a preliminary screen — he's evaluating whether you get the product and the mission, not quizzing you on Elixir. This is a vibes-and-fit call.
- 4+ years experience (you have 15+)
- Design and maintain production services at scale
- High-quality, tested code with ownership mentality
- Web security fundamentals — they specifically call this out
- Interest in Bitcoin and River's mission
- Nice-to-haves: fintech, React, Elixir, Postgres, K8s, scaling experience
- Product engineer identity — you care about the whole product end-to-end, not just tickets. James is a product leader, this resonates.
- Security awareness — your cover letter already flagged interest in threat modeling for auth, funding, withdrawals. This is genuinely important at a company custodying $800M+ in Bitcoin.
- React depth + willingness to learn Elixir — be honest, you haven't used Elixir in production but you pick up languages fast.
- Modernization experience — leading legacy-to-React at Vermont Mutual maps to building and evolving products.
- Small team, high leverage — 45 people holding $800M+. Your experience driving work across 10-20 person teams fits.
- You genuinely like what they're building — transparency, proof of reserves, Bitcoin-only conviction. Don't fake this, but don't undersell it either.
- "River Link is a really clever UX for Bitcoin transfers — what's the adoption been like? Do you see it as a growth/acquisition channel or more of a retention feature?"
- "The proof of reserves and publishing financials feels like a genuine differentiator post-FTX. How does that transparency commitment show up in day-to-day product decisions?"
- "How do you think about the balance between the DCA/savings users and the more active traders? Is there a primary persona the product is built around?"
- "How do you split concerns between React and Elixir in the codebase? Is it a classic API-backend/SPA-frontend split or something more interleaved?"
- "With custody built in-house rather than using a third party, how does the security review process work for changes that touch funds or transactions?"
- "What does the deploy cycle look like — how often does code ship to production?"
- "How big is the engineering team right now, and how are squads or teams organized?"
- "What's the collaboration model between product and engineering? Are engineers involved in scoping and discovery, or does product hand off specs?"
- "I saw you're also hiring for a Staff ML/AI full-stack role — what's the AI investment about? Fraud detection, personalization, something else?"
- "Who's the typical River customer today — mostly individual long-term holders, or are you seeing growth in business accounts and private clients?"
- "What do customers love most? What's the biggest pain point you're trying to solve right now?"
- "Alex has talked about being 'laser-focused' on the US Bitcoin market. Is international on the roadmap at all, or is that a deliberate constraint?"
- "What drew you personally from AdTech at Pinterest/Meta to Bitcoin financial services?"
- Don't overstate Bitcoin expertise — you're enthusiastic, not a maximalist veteran
- Don't pretend you know Elixir — honest curiosity is better
- Don't bring up salary (it's a preliminary screen, let them raise it)
- Don't badmouth other companies in the space
| Company | River (river.com) |
| Founded | 2019, San Francisco |
| CEO | Alex Leishman (ex-Airbnb security, Stanford CS) |
| Your interviewer | James Page, CPO (ex-Pinterest, ex-Meta) |
| Team size | ~45 people |
| Funding | $70M (Series B $35M, May 2023) |
| AUM | $800M+ in Bitcoin custody |
| Stack | React, Elixir, Postgres, K8s |
| Salary range | $150K-$220K (you asked $160K) |
| Offices | SF, NYC, Columbus (remote OK) |
| Call time | 4:00-4:20 PM EDT, Google Meet |