Software Engineer — Symbal

Type: Full-time | On-site (SF / Palo Alto; remote for truly exceptional candidates) | San Francisco, CA · Palo Alto, CA Compensation: $150,000–$175,000 base + 0–1% equity Hiring count: 1 Visa sponsorship: Yes — H-1B, OPT Reports to: CTO

Symbal builds RL training data and task-construction infrastructure for frontier AI labs, and works with enterprises and health systems to deploy custom AI agents. Founded by teams with deep experience in AI research and agent systems, the company is scaling both its task-generation pipeline and its agent-deployment business.

Founded: 2025 | Team size: 1–10 (Seed) | Backing: Founders Fund Industry: AI Tools Website: symbal.ai Office: San Francisco, CA · Palo Alto, CA

• Frontier AI at the source: Build the RL task infrastructure that trains and evaluates frontier models — a Founders Fund–backed seed company.
• Deep ownership, early: A specialist, high-ownership seat reporting directly to the CTO, owning a full division of engineering task-building work.
• Specialist leverage: Your single deepest domain (DevOps, MLE, systems, Rust, algorithms, or full-stack) is the point — depth drives real leverage here, not generalist breadth.

• Not available — no intake call transcript or notes were on the role page. (An intake video is posted but not transcribed.)

Accelerate task creation for Symbal's RL training pipeline — a specialist role at the intersection of engineering, task design, and system architecture.

• →Own task construction: design and build long-horizon, high-difficulty RL tasks that meet Symbal's specifications within time constraints
• →Build internal tools and infrastructure to help contractors create tasks faster and at higher quality
• →Contribute to custom agent implementations for enterprise customers and health systems
• →Own one core technical domain deeply (DevOps, MLE, systems design, Rust, algorithms, or full-stack) and lead that division of engineering tasks
• →Ship and iterate on systems that power Symbal's core task-generation pipeline

Tech stack: Not specified on role page.

• 1 to 5 years engineering experience, flexible for exceptional candidates
• Deep specialization in one domain (DevOps, MLE, system design, Rust, algorithms, or equivalent)
• Strong software engineering fundamentals alongside the specialization
• Palo Alto/SF in-person preferred; remote open for truly exceptional candidates
• Startup pace 9am–9pm, six days a week; high-ownership role reporting to CTO

• Rare depth in one engineering area
• Grit and execution velocity
• Specialist who can also lead a division

• No clear specialization or jack-of-all-trades only
• Cannot articulate their specialization clearly

Salary$150,000–$175,000Equity0%–1%Schedule9am–9pm, six days a week (non-negotiable)On-site policySF / Palo Alto in-person preferred; remote for truly exceptional candidatesVisa sponsorshipH-1B, OPTEmployment typeFull-timeLocationSan Francisco, CA · Palo Alto, CA

• None defined on the role page. The take-home assignment (Stage 3) is the primary evaluation instrument — see Interview Process.

Stage 1 — Pending Approval — Candidates awaiting initial approval. Stage 2 — Intro Call Stage 3 — Take-home assignment — Design a sample task based on something you find unique or interesting. Must be a long-horizon task with calibrated difficulty, completed within a time constraint you specify. Stage 4 — Take Home Review (45 min) — Review call to discuss your take-home, your specialization, and fit for the role. Stage 5 — Offer Extended Stage 6 — Candidate Hired — Candidate accepts and starts.