Logo
Weekday AI (YC W21)

Founding Software Engineer (Full-Stack)

Weekday AI (YC W21), San Francisco

Save Job

3 days ago Be among the first 25 applicants

Get AI-powered advice on this job and more exclusive features.

This role is for one of the Weekday's clients
Salary range: $150K - $190K / 2.00% - 3.00%
Experience: 3+ YoE
We are seeking a highly skilled Founding Software Engineer (Full-Stack) to join our team in San Francisco, CA. This role focuses on solving the challenge of automating all the time-consuming tasks developers face outside their code editor — from deployments to performance, incidents, and bug resolution — using agentic workflows and AI.
You will work directly with two experienced co-founders: one who has led engineering efforts at scale for internal developer platforms used by thousands of engineers, and another who has successfully founded, scaled, and sold a developer-focused startup.
Requirements
Key Responsibilities

  • Event-Driven Backend Development: Architect a Node.js / Next.js / TypeScript and Supabase stack. Design schemas, event flows, and ingest dev tools webhooks to power a real-time personalized engineering portal.
  • LLM Agentic Workflows: Build a system of AI agents, incorporating MCP, tool usage, memory, retry logic, context updates, and feedback loops.
  • Agent Experience (AX): Design intuitive human-agent interaction interfaces, collaborating closely with engineers to refine productivity-focused digital co-pilots.
  • System Design & Technical Strategy: Partner with leadership to define scalable technical paths, balancing rapid delivery with integration flexibility for diverse developer tools and open-source community support.
Ideal Candidate Profile
  • Full-stack 0-to-1 builder with production deployment experience, particularly in rapidly shipping Next.js applications and event-driven, serverless architectures.
  • Strong interest in agentic product experiences and the impact of AI on developer productivity.
  • Prior experience as a founder or founding engineer who has built products from scratch that gained real users or paying customers.
  • Problem-solver who thrives on tackling hard challenges with grit and persistence.
  • Comfortable navigating ambiguity, prioritizing effectively, and adapting to changing circumstances.
  • Excellent communication skills with a high degree of candor and openness.
  • Deep commitment to supporting engineers in overcoming operational inefficiencies.
This Role is Not a Fit If You
  • Are not based in the Bay Area (team will be co-located in San Francisco).
  • Are unwilling to work six days a week (Sundays off).
  • Are not excited about leveraging modern code-generation tools (e.g., Cursor, Windsurf, Claude Code).
  • Are uncomfortable with frequent deletion/refactoring of large portions of code.
  • Prefer rigid structures over dynamic, fast-changing environments.
  • Avoid direct and honest feedback exchanges.
The Opportunity
  • Work alongside two seasoned co-founders — one with deep experience scaling developer platforms, and another with proven success building and exiting a dev tools startup.
  • Gain end-to-end startup exposure, from customer support and user interviews to events and core development.
  • Become the first engineering hire at a company aiming to define the next category-leading developer platform used and paid for by leading tech companies

Seniority level

  • Seniority level

    Mid-Senior level

Employment type

  • Employment type

    Full-time

Job function

  • Job function

    Other
  • Industries

    IT Services and IT Consulting

Referrals increase your chances of interviewing at Weekday AI (YC W21) by 2x

Get notified about new Software Engineer jobs in San Francisco, CA .

San Francisco, CA $160,000.00-$180,000.00 2 weeks ago

San Francisco, CA $130,000.00-$238,000.00 2 weeks ago

San Francisco, CA $150,000.00-$250,000.00 2 weeks ago

Full-Stack Software Engineer (Jr/Mid level)

San Francisco, CA $120,000.00-$180,000.00 1 month ago

San Francisco, CA $150,000.00-$230,000.00 3 months ago

Software Development Engineer I - Frontend & Mobile

San Francisco, CA $150,000.00-$176,000.00 3 months ago

San Francisco, CA $120,000.00-$190,000.00 9 months ago

San Francisco, CA $57.00-$61.00 2 days ago

San Francisco, CA $57.00-$61.00 2 days ago

San Francisco, CA $125,000.00-$175,000.00 2 months ago

San Francisco, CA $163,200.00-$223,200.00 2 weeks ago

Software Engineer, Frontend (All Levels)

San Francisco, CA $150,000.00-$180,000.00 6 days ago

Software Engineer, AI Intern (Winter 2026)

San Francisco, CA $57.00-$61.00 2 days ago

Software Engineer, AI Intern (Summer 2026)

San Francisco, CA $57.00-$61.00 2 days ago

San Francisco, CA $165,000.00-$165,000.00 2 years ago

San Francisco, CA $120,000.00-$200,000.00 2 years ago

Alameda, CA $130,000.00-$160,000.00 2 months ago

San Francisco, CA $140,000.00-$280,000.00 8 months ago

We’re unlocking community knowledge in a new way. Experts add insights directly into each article, started with the help of AI.

#J-18808-Ljbffr