Full-Time

Backend Engineer

DepthFirst

DepthFirst

51-200 employees

AI-native security platform detecting vulnerabilities

No salary listed

San Francisco, CA, USA

In Person

Bachelor's

Category
Software Engineering (1)
Required Skills
LLM
Python
React.js
Postgres
TypeScript
AWS
Redis
Next.js

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Requirements
  • At least 3 years of full-time experience in backend software engineering.
  • Experience building reliable and stable software products to solve user problems.
  • A bachelor's degree in Computer Science or Software Engineering, or equivalent industry experience.
  • Experience solving complex problems with simple, scalable solutions and making appropriate trade-offs.
  • Experience with backend engineering technologies including TypeScript, Python, Temporal, React, Next.js, PostgreSQL, Redis, large language models, and Amazon Web Services.
Responsibilities
  • Provide mentorship, set technical direction, and define best practices for backend engineering.
  • Architect and scale coding agent pipelines that scan and execute very large codebases to identify complex software vulnerabilities.
  • Build, maintain, and evolve evaluation benchmarks for artificial intelligence agents that reflect user problems.
  • Take ownership of the product by contributing to its architecture, performance, and long-term success.
Desired Qualifications
  • Familiarity with multiple programming languages is a plus.

DepthFirst (Patcherai) offers an AI-native security platform called General Security Intelligence (GSI) that analyzes a company’s code, infrastructure, and business logic to identify and remediate vulnerabilities. It uses AI-powered agents to build a deep contextual model of a system, enabling detection of complex issues such as business logic flaws and backdoors that traditional static tools might miss. The platform surfaces actionable fixes that can be merged directly into developers’ workflows, while reducing false positives and increasing true positives. Delivered as a SaaS to support DevSecOps, its goal is to secure software against automated and autonomous threats and improve security and developer efficiency; the company raised $40 million in Series A in January 2026 to scale R&D, go-to-market, and hiring.

Company Size

51-200

Company Stage

Series B

Total Funding

$140.8M

Headquarters

San Francisco, California

Founded

2024

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Simplify Jobs

Simplify's Take

What believers are saying

  • March 2026 Series B raised $80 million, bringing depthfirst to $120 million total.
  • June 2026 Dependency Firewall and July Open Defense credits expanded product surface and demand.
  • Depthfirst reported 20+ customers and 300% revenue growth over the last two quarters.

What critics are saying

  • Anthropic, GitHub, and Snyk can bundle similar scanning into broader developer suites in 2026.
  • Heavy dependence on dramatic research wins, like FFmpeg and NGINX, makes revenue story fragile.
  • A single failed high-profile exploit or missed zero-day would shatter trust and enterprise adoption.

What makes DepthFirst unique

  • Depthfirst pairs autonomous vulnerability discovery with ready-to-merge fixes, not just alerts.
  • Its Dependency Firewall blocks malicious packages before installation across the company.
  • The Open Defense Initiative embeds depthfirst inside critical open-source maintainers’ workflows.

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Benefits

Health Insurance

Vision Insurance

Dental Insurance

Meal Benefits

Company Equity

Growth & Insights and Company News

Headcount

6 month growth

-5%

1 year growth

-2%

2 year growth

-2%
Business Wire
Jun 1st, 2026
depthfirst launches Dependency Firewall to block malicious open-source packages before installation

San Francisco-based depthfirst has launched Dependency Firewall, a product that reviews and blocks malicious open-source packages before they're installed across a company. The system inspects every package download, regardless of who is installing it, and returns a verdict before installation, allowing approved packages through whilst quarantining suspicious ones and blocking malicious code. The firewall addresses growing security risks as attackers exploit open-source trust by publishing packages that mimic popular libraries. Verizon reported that 48% of data breaches in its 2026 DBIR involved ransomware, with malware attacks surging recently. Dependency Firewall uses depthfirst's agentic defence platform, which previously discovered NGINX Rift, an 18-year-old vulnerability. The company has raised $120 million from investors including Meritech Capital, Accel and Forerunner Ventures.

Business Wire
May 12th, 2026
depthfirst commits $5M in credits to help open source projects find and fix zero-day vulnerabilities

depthfirst, an applied AI security lab, has launched the Open Defense Initiative, committing up to $5 million in platform credits to help open source projects discover and fix vulnerabilities. The programme targets widely deployed infrastructure software where vulnerabilities would have significant downstream impact. The company disclosed it identified 12 previously unknown memory corruption vulnerabilities in FFmpeg using approximately $1,000 in compute, compared to Anthropic's reported $10,000 spend for similar scanning. Some vulnerabilities dated back to 2009, and patches were autonomously generated by depthfirst's platform. The initiative is currently partnering with maintainers of FFmpeg, Envoy and Kata Containers, whilst proactively analysing projects including Linux, OpenSSH and PostgreSQL. depthfirst has raised $120 million from investors including Meritech Capital, Accel and Forerunner Ventures. Maintainers can apply at opendefense.dev.

Business Wire
Apr 1st, 2026
Applied AI Lab depthfirst Announces $80 Million in Series B Funding

depthfirst, an applied AI lab on a mission to secure the world’s software, today announced its $80M Series B round, led by Meritech Capital, with participati...

Forbes
Mar 31st, 2026
Depthfirst raises $120M at $580M valuation to build AI defence against AI hackers

Depthfirst, an AI cybersecurity startup, has raised $80 million at a $580 million valuation, just two months after a $40 million Series A round. The company is developing "General Security Intelligence" to autonomously detect vulnerabilities and defend against malicious AI attacks. Founded in 2024 by former Google Deepmind researcher Andrea Michi, former Databricks security head Qasim Mithani, and ex-Block cybersecurity chief Daniele Perito, Depthfirst builds AI models from scratch using reinforcement learning rather than adapting existing large language models. The company has over 20 customers and claims 300% revenue growth over the past two quarters. Depthfirst is launching its first in-house model this week, targeting security weaknesses in cryptocurrency smart contracts. Meritech Capital led the Series B round, with total funding now exceeding $120 million.

Startup Weekly
Jan 16th, 2026
depthfirst raises $40M Series A to secure software with AI-powered threat detection

depthfirst, an applied AI lab focused on software security, has raised $40 million in a Series A round led by Accel. Alt Capital, BoxGroup, Liquid 2 Ventures, Mantis VC and SV Angel participated, alongside angel investors including Jeff Dean and Kirsten Green. Founded in 2024, depthfirst has developed a General Security Intelligence platform that detects, triages and remediates vulnerabilities across software and infrastructure. The company's AI agents uncover eight times more true-positive vulnerabilities than traditional static analysis tools whilst reducing false positives by 85 per cent. The founding team includes technical leaders from Google DeepMind, Databricks and Faire. The funding will support research and development, go-to-market efforts and hiring across applied research, engineering, product and sales.