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Best X BuildsBrowse ↓

Startups Jobs Posted on X (Twitter)

Early-stage companies that said so. Not every Series B that posted a Greenhouse link. 111 roles on this page.

111 roles · updated 2026-09-27

Founding Engineer

Tensol

AI agents that link requirements to test data for hardware teams. Send a recent project. Posted by the founder.

Sep 27, 2026

engineeringaifoundingstartup

Designer

Propaganda

Design on the same hiring tweet. Posted by someone on the team. DM.

Sep 27, 2026

designstartup

Product Marketer

Propaganda

Product marketing on the same hiring tweet. Posted by someone on the team. DM.

Sep 27, 2026

contentproductstartup

Lead Product Designer

Vaani

First product designer. Speech models and infra. Co-own flows with the founders. Posted by a founder.

India · Sep 27, 2026

designproductaifoundingstartup

Engineer

Pilgrim Labs

Hardware that engineers, manufactures, and deploys biology. Posted by founding team. Reach out.

United States · Sep 24, 2026

engineeringstartupfounding

Scientist

Pilgrim Labs

Scientists on the same hiring tweet. Posted by founding team. Reach out.

United States · Sep 24, 2026

researchstartup

Engineer

Kepler

Engineers at Kepler. Posted by someone on the team.

Sep 24, 2026

engineeringaistartup

Founding Marketer

Kepler

Founding marketer on the same hiring tweet. Posted by someone on the team.

Sep 24, 2026

contentfoundingstartup

GTM Engineer, Revenue Systems

Warp

Own Salesforce, Snowflake, Clay, Outreach, Gong as Warp goes from a handful of reps to 100+. NYC, in person. Posted by the CEO.

New York, United States · Sep 22, 2026

engineeringstartup

SEO Lead

TripleSpeed

SEO lead, 25-50 LPA, Bangalore, equity. Posted by the founder.

Bangalore, India · Sep 21, 2026

contentstartup

Head of Marketing

Showpo

Brand-led marketing lead for global growth and US expansion. Sydney, sponsorship available. Posted by the founder.

Sydney, Australia · Sep 20, 2026

contentstartup

Founder's Office / Chief of Staff

16VC

Fundraising, investing, founders, research. Bengaluru, London, or San Francisco. Email hr@16vc.co. Posted by the GP.

Bengaluru, India / London, UK / San Francisco, US · Sep 20, 2026

startupotherfounding

Socials

Soapbox

Run Twitter, LinkedIn, Instagram, and TikTok for a European VC newswire. Posted by the founder.

Europe · Sep 20, 2026

contentstartup

Chief of Staff

Corgi

Chief of staff in San Francisco. Email b@corgi.com with the role in the subject. Posted by the founder.

San Francisco, United States · Sep 20, 2026

otherstartup

Investor Relations

Corgi

Investor relations in San Francisco. Email b@corgi.com. Posted by the founder.

San Francisco, United States · Sep 20, 2026

otherstartup

Director of Marketing and GTM

True Markets

Director of marketing and GTM in Noho, NYC. Posted by the founder and CEO.

New York, United States · Sep 20, 2026

contentstartup

FRO Builder / Venture Studio Partner

Convergent Research

Launch focused research orgs for AI resilience: compute governance, biosecurity, formal verification. Posted by a teammate.

Remote, United States · Sep 20, 2026

researchaistartup

Sales Recruiter / GTM Talent

Audacious HQ

Recruiting, community, and platform for GTM in SF and NYC. Posted by the founding partner.

San Francisco / New York, United States · Sep 20, 2026

otherstartup

Head of Technical Investing

Apoorva Mehta

Source and evaluate personal investments in agents and data. 12-18 month tour. Email jobs@apoorvamehta.com. Posted by the Instacart founder.

Remote · Sep 20, 2026

otheraistartup

Founding Engineer

Shorebird

Founding engineer at a small Flutter tooling team. Posted by a teammate.

Remote, United States · Sep 18, 2026

engineeringfoundingstartup

Business Operations

Shorebird

Business operations at a small Flutter tooling team. Posted by a teammate.

Remote, United States · Sep 18, 2026

otherstartup

Lead Aerothermal Engineer

Hop Aero

Lead aerothermal for hypersonic rocket cargo. Orange, CA. Posted by the founder.

Orange, CA, United States · Sep 17, 2026

engineeringstartup

Lead GNC Engineer

Hop Aero

Lead GNC for hypersonic rocket cargo. Orange, CA. Posted by the founder.

Orange, CA, United States · Sep 17, 2026

engineeringstartup

Propulsion Mechanical Engineer

Hop Aero

Propulsion mechanical engineer for hypersonic rocket cargo. Orange, CA. Posted by the founder.

Orange, CA, United States · Sep 17, 2026

engineeringstartup

Designer

Doji

Designer for social fashion shopping. NYC. Taste required. Posted by the company and the CEO.

New York, NY · Aug 28, 2026

designstartup

Founding Engineer

Doji

Founding engineer, NYC. Same Doji careers post.

New York, NY · Aug 28, 2026

engineeringfoundingstartup

Research Engineer

Doji

Research engineer, NYC. Same Doji careers post.

New York, NY · Aug 28, 2026

engineeringresearchaistartup

Founding Engineer

BotBot

Founding engineer and founding design engineer. AI-native company building. Posted by the CEO.

Aug 27, 2026

engineeringfoundingaistartup

Founding Engineer

EarnKit

Founding engineer to make it simple for agents to earn onchain. DM the founder.

Aug 27, 2026

engineeringfoundingweb3startup

Engineer

aaru

Engineers, NYC in person. Same team that is already hiring designers. DMs open.

New York, NY · Aug 27, 2026

engineeringstartup

Design Engineer

Baro

Design, build, and maintain websites for consumer brands. Contract, NY preferred. a16z speedrun. DMs open.

New York, NY · Aug 27, 2026

designengineeringstartup

Designer

Winks

First designer. Static ads, email, web, bonus for video. AI tools required. Freelance. Posted by the cofounder.

Aug 27, 2026

designstartup

Founding Engineer

Sugar

Founding engineer in NYC. Equity plus competitive comp, $10k referral. Posted by the founder.

New York, NY · Aug 27, 2026

engineeringfoundingstartup

AI Engineer

Karwaan Labs

First engineer from India. Remote-first, high ownership. Posted by the team.

Remote (India) · Aug 27, 2026

engineeringaifoundingstartup

Founding GTM Lead

Worldline

0 to 1 enterprise and public-sector GTM in India. Mid to senior, remote. Posted by the founder.

Remote (India) · Aug 27, 2026

otherfoundingstartup

Marketing Lead

Gravityfast

Own marketing end to end. Bangalore-based startup, fully remote. DM resume and proof of work.

Remote (India) · Aug 27, 2026

contentstartup

Founding Growth Lead

Sixtyfour

Founding growth for agents that do enterprise research. SF in person. $120k to $150k plus equity. Posted by the CEO.

San Francisco, US · Aug 27, 2026

otherfoundingstartup

Robotics Engineer

Valstad

Engineers obsessed with robotics who want to change how America builds ships. Posted by the founder.

Aug 26, 2026

engineeringstartup

Lead Mechanical Engineer

Poseidon Aerospace

Lead mechanical engineer for safety-critical flight hardware and composite airframes. Posted by the company.

Aug 26, 2026

engineeringstartup

Software Engineer

Tross

Backend/platform SWE, 1 to 5 years. Reverse engineering, CTF, and cloud are pluses. 25 to 45 L (cash + ESOP). Bangalore in-office.

Bangalore, India · Aug 25, 2026

engineeringsecuritystartup

Designer

aaru

Designers who ship to code. NYC in person. Posted by a designer who just joined the team.

New York, NY · Aug 25, 2026

designstartup

Founding Engineer

Cluster

Founding engineer at Cluster (a16z speedrun). Infra between agents and markets. DM the cofounder.

Aug 25, 2026

engineeringaifoundingstartup

Founding Engineer

Loura

Founding engineer in Riyadh. Ambient AI for complex orgs. Cash plus equity. DM the cofounder.

Riyadh, Saudi Arabia · Aug 25, 2026

engineeringaifoundingstartup

Network Engineer

HypeProxies

Network engineer. $1.5M to $5.4M ARR in 20 months. Posted by the founder.

Aug 25, 2026

engineeringstartup

Platform Engineer

HypeProxies

Platform engineer. Same founder thread as the network role.

Aug 25, 2026

engineeringstartup

Design Lead

HypeProxies

Design lead. Same founder thread.

Aug 25, 2026

designstartup

Founding Business Generalist

Neosigma

Founding generalist across product, GTM, strategy, and partnerships. Former founders and early operators. Posted by the CEO.

Aug 25, 2026

foundingproductstartup

Engineer

Magic Patterns

Engineer at the AI design tool. Number one goal: having fun.

Aug 20, 2026

engineeringdesignstartupai

Founding Engineer

Polar Browser

Founding engineer for an AI browser that automates hours of work. Email hiring@polarbrowser.com with 2–3 extraordinary things you've done.

Aug 20, 2026

engineeringfoundingstartupai

Founding Designer

Polar Browser

Founding designer for an AI browser a billion knowledge workers could use every day.

Aug 20, 2026

designfoundingstartupai

Full-Stack Engineer

VeryAI

Scale the biometric system that stops spam, blocks bots, and verifies real people and their agents.

Aug 19, 2026

engineeringaistartup

Research Engineer, Lab Automation

Periodic Labs

Turn scientists' experiments into hardware setups and instrument workflows. Up to $250k. a16z Build list, Aug 17.

Menlo Park, US · Aug 18, 2026

engineeringresearchaistartup

Lead Software Engineer

Northwood Space

Lead the Cloud team: antenna scheduling, booking, network orchestration. Up to $260k. a16z Build list.

Torrance / Los Angeles, US · Aug 18, 2026

engineeringstartup

Head of Engineering

Inferact

Head of Engineering on the vLLM inference stack. Up to $280k, SF. a16z Build list.

San Francisco, US · Aug 18, 2026

engineeringaistartup

Chief Engineer, Defense

Astro Mechanica

Top technical authority for the military aircraft program. Propulsion, avionics, flight controls. Up to $300k. Secret clearance. a16z Build list.

San Francisco, US · Aug 18, 2026

engineeringstartup

Product Manager

favorited

Own notifications, sharing, and core mobile flows. Up to $168k. a16z Build list.

Santa Monica, US · Aug 18, 2026

productstartup

AI Engineer

Taste Labs

Research and design-engineer roles to train models on taste and creative judgment. Posted on the a16z Build list.

Aug 18, 2026

aiengineeringresearchdesignstartup

Product Manager, Consumer

General Medicine

PillPack founders. Own finding, pricing, booking, and follow-up for consumer healthcare. a16z Build list.

San Francisco, US · Aug 18, 2026

productstartup

Founding Engineer

Munari

a16z Speedrun. Reliability infra so robots work in the real world, not just the lab. On-site SF.

San Francisco, US · Aug 18, 2026

engineeringaifoundingstartup

Founding Engineer

Discovered Materials

$9M to build AI scientists that discover semiconductor materials. a16z Build list.

Aug 18, 2026

engineeringaifoundingstartup

Product Designer

Boltz

MIT Jameel Clinic spinout, $28M seed. Design how scientists use AI models for drug discovery. a16z Build list.

London / Remote · Aug 18, 2026

designaistartup

Full Stack Engineer

Airbase

Rebuild US radio spectrum infrastructure. Up to $225k, NYC. a16z Build list.

New York, US · Aug 18, 2026

engineeringstartup

Structures Engineer

Galadyne

Ex-SpaceX propulsion lead. Design primary and secondary structures for flight vehicles. a16z Build list.

Austin, US · Aug 18, 2026

engineeringstartup

Senior Product Engineer

a16z New Media

Build tools that help founders grow faster. Work with the a16z New Media team in SF.

San Francisco, US · Aug 17, 2026

engineeringproductstartup

Member of Technical Staff

OpenEvidence

Elite engineer on special projects with the founders. Sequoia partner Shaun Maguire posting. Medical AI used by most US doctors.

San Francisco / Miami, US · Aug 17, 2026

engineeringaistartup

Founding Product Designer

Inferact

Define how vLLM and Inferact look and feel. Posted on the a16z Build list.

San Francisco, US · Aug 17, 2026

designstartup

Founding Engineer

Tenera

a16z Speedrun-backed. Predict how users react to software before you ship. Own agent infra, backend, and frontend.

San Francisco, US · Aug 17, 2026

engineeringaifoundingstartup

AI Product Engineer

Town

Personal AI assistant after a $55M Series A. Rethink email, calendar, and contacts. Posted by a16z New Media.

San Francisco / New York, US · Aug 17, 2026

engineeringaiproductstartup

Design Leader

Gravity

Invent the design language for human and agentic care. Clinician and patient interfaces. a16z Build list.

New York, US · Aug 17, 2026

designfoundingstartup

Software Engineer

Uplift

Ex-SpaceX/Tesla founders, $7M out of stealth. Hiring software, mechanical, electrical, manufacturing. Posted by a16z New Media.

United States · Aug 17, 2026

engineeringstartup

Product Engineer

Runta

Safer execution environment for agents. $20M seed. SDK, CLI, APIs, DX. Up to $200k. a16z Build list.

San Francisco, US · Aug 17, 2026

engineeringproductaistartup

Full Stack, Android, Mechanical and Hardware Engineer

Flyby Robotics

Build the aerial intelligence platform in person in LA. Full stack (React/TypeScript/Go/Python), Android (Kotlin/Compose), senior mechanical and senior hardware (PCB/firmware). US citizen or permanent resident.

Los Angeles, CA · Aug 15, 2026

engineeringstartup

FDE, Full Stack and ML Engineer

Alloy Robotics

Just raised $8M at an $80M valuation to build agents over robotics data. Hiring FDE, Full Stack Software Engineer, ML Engineer, plus AE, Chief of Staff and Growth. Usage up 51% MoM.

Remote (US) · Aug 14, 2026

engineeringaistartup

Lead Engineer, Senior PM and Designer

Elfina Health

Building India’s next therapy, psychiatry and coaching journey. Lead Engineer (6–7+ years) owns tech and infra; Senior PM shapes clinical + tech + ops; Designer owns visual language and web.

India · Aug 14, 2026

engineeringproductdesignstartup

Product Designer

Convallax

Product designer for options on prediction markets. Trading, DeFi, perps or prediction-market UI experience.

Aug 14, 2026

designweb3startup

Product Manager

Skydo

Three PM roles. 2–4 years PM experience. Cross-border B2B payments.

Bangalore, India · Aug 13, 2026

productstartup

Engineers (Rust, Actors, OSS)

Rivet (YC W23)

Open-source infra for AI, built on Rivet Actors and agentOS. For engineers who love Rust, actors, OSS and self-hosting. All time zones.

Remote (Worldwide) · Aug 12, 2026

engineeringaiopen-sourcestartup

AI Engineer

Agent Integrator

Build and deploy AI agents into production. Full ownership plus equity and revenue share.

Remote · Aug 9, 2026

aiengineeringstartup