Founding Engineer — Brokerage Core Execution Engine (Remote/Hybrid)

Prediction markets are having their breakout moment — but the ecosystem is badly fragmented. Liquidity, prices, and positions are scattered across venues like Polymarket, Kalshi, Limitless, and Predict.fun, and none of them talk to each other. A serious trader has to open an account on each one, fund each separately, watch prices across multiple tabs, and still has no single view of their true exposure or PnL. There's no Interactive Brokers, no Robinhood, no unified account for this entire asset class. Senal is building that layer: one account to trade, track, and follow positions across every major prediction market. Deposit once, and we route your orders to the best venue, unify your positions into a single portfolio, and let you follow and copy the best forecasters. We're an early-stage, AI-native team, and we're building the system that makes all of this possible right now — V2. The Role You'll be the founding engineer for V2's brokerage core — the most critical and highest-stakes engineering hire we'll make. You'll architect and build the execution engine, smart order router, OMS, ledger, and the systems around them, working directly with our CTO and founders from a blank page. This is a deep-ownership role. Early on, you may be the single person responsible for the entire money path. As we grow, you'll shape the architecture, the standards, and the team around this core. We're hiring at the senior-to-staff level. What You'll Build and Own Execution engine & smart order router — best-execution routing across venues; clean handling of partial fills, slippage, retries, and venue failures Ledger, custody accounting & reconciliation — per-user balances, double-entry bookkeeping, idempotent money movement, continuous reconciliation Venue connectors — robust integrations with on-chain (Polymarket/Polygon/USDC) and off-chain (Kalshi) venues Cross-venue position unification — single PnL model spanning binary, multi-outcome, and scalar markets CopyTrade execution — reliable real-time trade mirroring Reliability, correctness & observability — monitoring, alerting, and reconciliation tooling Hard Requirements You've built trading systems in production — at an exchange, brokerage, prop/HFT shop, or trading-infrastructure company. You've personally shipped execution, OMS, order-routing, or settlement systems where real money was on the line. This is the requirement we will not flex on.

• Deep understanding of order lifecycle, concurrency, and money correctness — partial fills, race conditions, idempotency, reconciliation
• 5+ years of production backend engineering
• Strong with real-time, event-driven, concurrent systems — queues, streaming, state machines

Strongly Preferred Smart order routing or multi-venue execution experience Custodial systems, ledgers, or settlement infrastructure - Security mindset — you design against how systems break and lose money Nice to Have Crypto/web3 familiarity — EVM, wallets, on-chain settlement, USDC Experience with regulated financial products You actively trade or follow prediction markets Backend: TypeScript / Go / Rust (etc.) — we care about your systems judgment, not the specific language On-chain: EVM, viem/ethers, Polygon/Base Compensation & Logistics Competitive salary + meaningful founding-team equity - Location: SF Bay Area, Hybrid or Remote #J-18808-Ljbffr Senal