---
title: 'Senior Software Engineer, Full Stack at Antithesis'
canonical: 'https://feeny.ai/job/senior-software-engineer-full-stack-antithesis-vienna-gt0ar79h0t79'
type: 'job'
last_seen: '2026-10-18'
---

# Senior Software Engineer, Full Stack at Antithesis

- **Company:** Antithesis
- **Location:** Vienna, VA
- **Employment:** full-time
- **Work type:** onsite
- **Posted:** 2026-10-07
- **Last confirmed live:** 2026-10-18
- **Apply:** https://jobs.ashbyhq.com/antithesis/08807dc1-1d8a-46f0-8238-329688082556

## Job description

About Antithesis: We've been quietly reinventing how the world thinks about software reliability, and we're just getting started! At Antithesis, we start at the foundations – we run entire software systems inside a deterministic simulation and break them in every way imaginable. Every issue then comes with a perfect reproduction, so you can identify root causes fast instead of spending days trying to recreate what went wrong.

The rise of AI-generated code has made this work more urgent than ever. Agents can write code faster than any human, but speed doesn't matter much when the output is buggy, stuck in review, or slipping through undetected. The verification bottleneck is real, it's growing, and solving it is one of the most consequential problems in software right now. That's what you'd be working on.

We're well-funded and deeply technical, the kind of place where the hardest problems get the most attention and the best ideas win regardless of who has them. If you want to do work that actually moves the needle on how reliable software can be, keep reading.

About the Role: Antithesis is looking for a Full Stack Engineer to join our engineering team. This role primarily focuses on the Notebook - the reactive computing platform that all Antithesis UX is built on top of. As a Notebook Engineer, you will do a mix of deeply technical and heavily product-focused work.

What You’ll Do:

- Make improvements to a reactive engine for executing Javascript (imagine Jupyter where everything auto recalcs).
- Own a new feature, from the front end to the data layer. This includes adding features as needed to our custom database (or proxy, or API server) to get the feature done.
- Create Property Based Tests and Antithesis workloads to test the things you create.
- Work with our product managers to design and scope features.
- Develop build and deployment logic in Nix.

What We’re Looking For:

- Experience working with complex customer facing-products.
- Be very comfortable with Typescript, and ready to pick up a bit of Rust work.
- Have strong technical skills and a solid programming background in algorithms and data structures.
- Experience building static and dynamic websites
- Understanding of how the internet and browsers work
- (bonus) experience with Nix
- (bonus) have ideas about leveraging AI effectively
- (bonus) a prior history with PBT

## About Antithesis

## Company Overview
- **One-liner**: Antithesis provides an autonomous software testing platform that uses deterministic simulation and state space exploration to exhaustively find and reproduce bugs in complex, distributed systems.
- **Entity Type**: Private (Series A)
- **Headquarters**: Vienna, Virginia, United States (with satellite offices in London, UK and San Francisco, California)
- **Founded**: 2018
- **Founders**: Will (CEO), Ben (CTO), and Dave (co-founder) – full last names not publicly disclosed

## Core Business
- **Primary industry/industries**: Software testing, autonomous reliability, developer tools, infrastructure software
- **Target customers**: B2B, Enterprise – companies building complex distributed systems (e.g., databases, cloud infrastructure, fintech, blockchain)
- **Mission or purpose statement**: “De‑risk agentic development of critical systems” by exposing bugs without human review, false positives, or risking production.

## Products & Services
- **Antithesis Platform**: A SaaS/on‑prem platform that runs a customer’s complete system in a fully deterministic, ephemeral simulation. It exhaustively analyzes behavior using fuzzing and state space exploration, automatically exposes bugs, provides a root cause and perfect reproduction, and arms developers (including AI agents) with high‑signal correctness feedback.

## Market Standing
- **Valuation/Market Cap**: Not disclosed
- **Key Metric**: Total Funding – $182 M (latest round: $105 M Series A announced December 3, 2025)
- **Notable Investors/Partners**: Amplify Partners, Spark Capital, Tamarack Global, Patrick Collison, Sholto Douglas, and 31+ other investors. Customers include Jane Street, MongoDB, Confluent, and Tigris Data.
- **Growth Signals**: Launched out of stealth in 2024; 19 open job openings as of mid‑2026; customers report 40 × faster change verification, 10 × faster time‑to‑release, and discovery of severe bugs missed by all other testing.

## Competitive Advantages
- **Deterministic replay** of every bug found – eliminates the “cannot reproduce” problem.
- **Exhaustive state space exploration** that catches unknown unknowns without false positives.
- **Runs the entire system** (not unit/integration tests) – simulates production‑like conditions.
- **Already trusted by elite engineering teams** (e.g., quantitative trading firm Jane Street, leading database companies) – a strong reference moat.

## Strategic Focus
- Accelerate product innovation and expand support for **agentic development** – help AI agents build bug‑free code by providing high‑signal correctness feedback.
- Broaden platform coverage across **databases, cloud infrastructure, fintech, blockchain**, and other critical system domains.
- Scale go‑to‑market and customer success teams to meet enterprise demand.

## Why Work Here
- **Culture**: “Collaborative, highly technical, and customer‑focused” – deep‑tech environment solving hard distributed‑systems problems.
- **Work policy**: In‑office daily (Vienna, London, or San Francisco) to facilitate tackling difficult challenges together.
- **Perks & engineering culture**: Well‑funded startup with a long‑term mindset; team includes veterans from FoundationDB, Apple, Google, and MongoDB; emphasis on autonomy, technical excellence, and fun.
- **Interview process**: Transparent and respectful – they publish a “No Ghost Policy” and welcome unsolicited applications from talented candidates.

## Sources
1. [antithesis.com – Careers](https://antithesis.com/company/careers/)
2. [antithesis.com – Homepage](https://antithesis.com/)
3. [antithesis.com – Leadership](https://antithesis.com/company/leadership/)
4. [cbinsights.com – Antithesis Company Profile](https://www.cbinsights.com/company/antithesis)
5. [theconsensus.dev – Antithesis Profile](https://theconsensus.dev/company/antithesis.html)

## Other roles at Antithesis

- [Legal Counsel](https://feeny.ai/job/legal-counsel-antithesis-vienna-f00gv84hr2d3) — Vienna, VA
- [Vice President of Customer Experience](https://feeny.ai/job/vice-president-of-customer-experience-antithesis-vienna-8x1f2pcaw38t) — Vienna, VA
- [Business Development Representative](https://feeny.ai/job/business-development-representative-antithesis-london-5j4dgedr67c4) — London, United Kingdom
- [Business Development Representative](https://feeny.ai/job/business-development-representative-antithesis-vienna-bs8yz1003j4z) — Vienna, VA
- [Senior Account Executive - PNW](https://feeny.ai/job/senior-account-executive-pnw-antithesis-san-francisco-y3vnybpq35f2) — San Francisco, CA
- [Applied AI Software Engineer, GTM](https://feeny.ai/job/applied-ai-software-engineer-gtm-antithesis-vienna-62xsbyyvcham) — Vienna, VA
- [Senior Field Marketing Manager](https://feeny.ai/job/senior-field-marketing-manager-antithesis-vienna-mjeja0sqfvxc) — Vienna, VA
- [Accounting Operations Manager](https://feeny.ai/job/accounting-operations-manager-antithesis-vienna-rtryqp5eanrf) — Vienna, VA
- [Billing & Revenue Ops Manager](https://feeny.ai/job/billing-revenue-ops-manager-antithesis-vienna-kgrgmtb99spj) — Vienna, VA
- [Senior Accountant](https://feeny.ai/job/senior-accountant-antithesis-vienna-4na1bqhbceq2) — Vienna, VA