OpenAI

OpenAI

Develops safe AI models and tools

Applied AI Engineer - Codex

Full-Time
No salary listed
Mid
London, UK
Hybrid

Three days on-site per week required; relocation assistance is offered.

About the job

Requirements
  • Demonstrated experience designing, building, and delivering software or artificial intelligence systems in enterprise environments, including taking systems from prototype to production.
  • Substantial personal contributions in code, architecture, evaluation, debugging, integrations, or production engineering.
  • High proficiency in Python and comfort working across modern software development environments.
  • Active use of artificial intelligence coding tools and a strong point of view on improving developer productivity and software engineering workflows.
  • Understanding of systematic evaluation for artificial intelligence coding systems, including representative tasks, automated evaluations, production signals, and developer feedback mechanisms.
  • Experience navigating enterprise production requirements such as developer tooling integrations, reliability, observability, security, privacy, data governance, performance, and cost.
  • Ability to connect technical decisions to developer workflows, adoption, engineering productivity, and measurable business outcomes.
  • Ability to communicate clearly and credibly across hands-on engineers, engineering leaders, security teams, product leaders, and executives.
  • Ability to lead technical workshops and hands-on sessions that help engineering organizations adopt new development workflows and technologies.
  • Ability to speak English fluently.
Responsibilities
  • Partner directly with engineering leaders and hands-on developers to identify high-value opportunities for Codex and translate them into technical architectures, implementation plans, evaluation strategies, and measurable success criteria.
  • Design, build, and deploy artificial intelligence-powered software development workflows that improve how engineering teams plan, write, test, review, debug, and deliver software.
  • Build prototypes, evaluation harnesses, reference implementations, integrations, workflow automations, and production accelerators in code.
  • Help customers progress from experiments to reliable production workflows, sustained developer adoption, and scaled impact across engineering organizations.
  • Design systematic approaches for evaluating artificial intelligence coding systems using representative software engineering tasks, automated graders, production signals, and developer feedback.
  • Make technical decisions across models, agents, tools, developer environments, integrations, reliability, observability, latency, cost, safety, security, and operational readiness.
  • Diagnose complex implementation challenges, reproduce failures, test hypotheses, and drive technical blockers toward resolution.
  • Lead technical deep dives, workshops, and hands-on enablement for advanced artificial intelligence coding workflows.
  • Gather insights from Codex deployments and translate them into product proposals, model feedback, and technical requirements for Product, Research, and Engineering teams.
  • Create reusable architectures, tooling, examples, guides, and technical patterns, including contributions to resources such as the OpenAI Cookbook.
  • Influence customer engineering strategy by helping technical leaders understand how artificial intelligence coding systems can reshape software development lifecycles, engineering practices, and organizational workflows.
Desired Qualifications
  • Experience with JavaScript, TypeScript, or another relevant programming language.
  • Experience in applied artificial intelligence or machine learning engineering, forward-deployed engineering, software engineering, developer tooling, customer engineering, solutions architecture, or technical consulting.
  • Experience using Codex or other artificial intelligence coding tools.

About the company

OpenAI conducts AI research and deployment to build advanced AI models and tools that help people automate tasks, be more creative, and make better decisions. Its products include ChatGPT, a conversational AI that can write, code, tutor, and assist in interactive tasks, and Sora, which can generate videos from text prompts. OpenAI’s models typically run through cloud-based services and subscriptions, with licensing and partnerships for broader use. The company operates a capped-profit model to balance generating revenue with ensuring safety, ethics, and long-term societal benefits. Its approach emphasizes safety, responsible deployment, and collaboration with researchers, governments, and institutions. The goal is to ensure artificial general intelligence, when it arrives, benefits all of humanity and minimizes risks.

Company Size

10,001+

Company Stage

Private

Total Funding

$196.5B

Headquarters

San Francisco, California

Founded

2015

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Simplify Jobs

Simplify's Take

What believers are saying

  • OpenAI says revenue hit $2 billion monthly, with enterprise above 40%.
  • August 2026 ChatGPT for Teens and Images 2.5 expand monetizable product lines.
  • Nvidia’s August 2026 $105 billion Ohio backing secures OpenAI’s compute buildout.

What critics are saying

  • September 5, 2026 lawsuits from Seattle Times and Newsday target training datasets and models.
  • Apple and New York Times litigation threatens discovery, injunctions, and forced retraining.
  • A court loss on copyright or trade secrets would freeze releases and damage the 2027 IPO.

What makes OpenAI unique

  • March 31, 2026 funding gave OpenAI $122 billion and an $852 billion valuation.
  • OpenAI’s Jalapeño chip program with Broadcom cuts inference costs versus Nvidia GPUs.
  • ChatGPT’s consumer brand funnels directly into enterprise adoption and workflow expansion.

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Benefits

Health insurance

Dental and vision insurance

Flexible spending account for healthcare and dependent care

Mental healthcare service

Fertility treatment coverage

401(k) with generous matching

20-week paid parental leave

Life insurance (complimentary)

AD&D insurance (complimentary)

Short-term/long-term disability insurance (complimentary)

Optional buy-up life insurance

Flexible work hours and unlimited paid time off (we encourage 4+ weeks per year)

Annual learning & development stipend

Regular team happy hours and outings

Daily catered lunch and dinner

Travel to domestic conferences

Growth & Insights and Company News

Headcount

6 month growth

5%

1 year growth

0%

2 year growth

4%
PR Newswire
Sep 21st, 2026
Quartile partners with OpenAI to bring AI-powered ad optimisation to ChatGPT's 1B weekly users

Quartile has become a technology partner supporting advertising in ChatGPT, expanding its retail media optimisation capabilities into conversational AI. The partnership allows participating advertisers to access ChatGPT advertising through Quartile's existing tools and workflows. ChatGPT features clearly labelled ads that are visually distinct from responses, which remain uninfluenced by advertisements. The platform has more than one billion weekly active users. The expansion reflects Quartile's "experts + AI approach", combining automation and data with strategic expertise from advertising professionals. CEO Daniel Knijnik stated that whilst AI creates new product discovery methods, technology alone doesn't create successful advertising strategies. Quartile supports thousands of brands and manages billions of dollars in annual advertising spend across major commerce and digital advertising channels.

Yahoo Finance
Sep 18th, 2026
OpenAI launches sponsored agents in ChatGPT ads with HubSpot and Shopify integrations

OpenAI launched Sponsored Agents this week, enabling users to start conversations with business-sponsored agents after clicking ChatGPT ads. HubSpot joined as the first CRM integration, allowing sales teams to follow up after conversations end, whilst Shopify became the first e-commerce partner. The development represents a shift towards automated ad systems that operate as background infrastructure, monitoring business KPIs and adjusting ad pipelines in real time rather than through dashboards. This is driving marketers to migrate spending towards highly automated platforms like Google Performance Max and Meta Advantage+. Amazon, Google, and Meta now control 58% of the US advertising market, up from 56% a year earlier, according to Madison & Wall estimates. These three companies captured disproportionate market growth, whilst other companies combined fell from 47% to 43%.

Yahoo Finance
Sep 18th, 2026
AI labs must hit $180B revenue run rate by year-end to justify trillion-dollar capex buildout, says Nvidia investor

Brad Gerstner, founder of Altimeter Capital, says leading AI labs must increase their combined annual revenue from roughly $100 billion to at least $180 billion by year-end to sustain the AI trade. Speaking at the All-In Summit, he called AI lab revenue "the single most important data point in the market today." Gerstner estimates that Anthropic, OpenAI, and xAI had a combined run rate of approximately $100 billion in July. The revenue growth is needed to support massive infrastructure spending by Microsoft and Alphabet, who are building computing capacity that AI labs rent. Altimeter held 9.41 million Nvidia shares worth $1.88 billion at 30 June, representing about 19% of its US equity portfolio. The firm also holds stakes in Anthropic and OpenAI.

Yahoo Finance
Sep 18th, 2026
OpenAI's $1.2T valuation signals AI boom still has legs, says Macquarie

Microsoft-backed OpenAI is reportedly raising funds at a valuation of up to $1.2 trillion, according to Macquarie analysts. This would place it above rival Anthropic, recently valued at roughly $965 billion. The funding discussions follow a rebound in OpenAI's commercial momentum, with annual recurring revenue reportedly doubling to $40 billion earlier this year. Macquarie analysts Paul Golding and Alex Luthringer said the GPT-5.6 and Astra releases demonstrate that improved model performance continues driving enterprise and consumer adoption. Macquarie views this development as supportive for SoftBank, which holds significant exposure to OpenAI and controls chip designer Arm. The bank maintains an Outperform rating on SoftBank, citing validation of its broader AI strategy spanning infrastructure, data centres, and robotics.

The Information
Sep 17th, 2026
Cooley and OpenAI launch GO Public tool to draft S-1 SEC filings

Law firm Cooley has partnered with OpenAI to launch GO Public, a tool designed to draft S-1 filings — documents companies must submit to the Securities and Exchange Commission before going public. The announcement was made on Thursday. Cooley lawyers can use prompts to operate GO Public, which has access to the firm's resources. The tool aims to streamline the preparation of regulatory filings required for initial public offerings.