Full-Time

Site Reliability Engineer

Citadel

Citadel

5,001-10,000 employees

Global hedge fund and alternatives manager

Compensation Overview

$105k - $300k/yr

+ Discretionary incentive compensation

Company Historically Provides H1B Sponsorship

London, UK + 1 more

More locations: New York, NY, USA

In Person

Bachelor's

Category
DevOps & Infrastructure (1)
Required Skills
Python
Git
DevOps

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Requirements
  • Minimum of a Bachelor’s degree in Computer Science, or a related STEM discipline, or equivalent experience
  • Strong background in computer science fundamentals, data structures, algorithms, distributed systems
  • Fully proficient in at least one modern structured programming language (Python preferred)
  • Comfortable with a range of current software development tools and practices (testing, source control, build systems, CI/CD, etc.)
Responsibilities
  • Understand the end-to-end flow across applications at a business level
  • Ensure the reliability, availability, and performance of applications in production
  • Own the automation of repetitive tasks and resolution of systematic issues
  • Investigate new ways to improve operations and define new solutions to solve technically complex systems issues
  • Identify and deliver green-field engineering solutions for issues based on root cause analyses
  • Own incident management and drive tactical and strategic solutions
  • Lead by evangelizing the SRE mindset to other teams
  • Learn from industry leaders, distinguished engineers and investment professionals
Desired Qualifications
  • SQL and database experience is a strong plus
  • Web UI experience (JavaScript, CSS, React) is a plus
  • Excellent written and verbal communication skills
  • Strong entrepreneurial spirit and the ability to adapt to changing requirements and technologies
  • A passion for learning and inventing novel approaches to hard problems

Citadel is an alternative investment manager and hedge fund that oversees capital for institutional clients like pension funds, endowments, and sovereign wealth funds. It uses a team of traders to invest in global financial markets, aiming to grow client assets through speculative opportunities and risk-taking. The firm earns money mainly through performance fees (a share of profits) and management fees (a share of assets under management). Citadel differentiates itself by its track record of profitability, large assets under management, and its focus on improving transparency and resiliency in markets such as the U.S. Treasury market, along with strong risk management and civic leadership. Its goal is to generate high returns for clients while helping maintain fair, efficient markets and expanding its client base and assets under management under leadership from Ken Griffin.

Company Size

5,001-10,000

Company Stage

Private

Total Funding

$15B

Headquarters

Miami, Florida

Founded

1990

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Simplify Jobs

Simplify's Take

What believers are saying

  • Citadel’s Wellington gained 5.9% in July 2026, lifting 2026 returns to 12%.
  • Tactical Trading and equities funds posted record July 2026 gains, both up 27% year-to-date.
  • Citadel Securities’ July 16, 2026 Crypto.com investment deepens crypto market-making relationships and deal flow.

What critics are saying

  • Citadel’s February 11, 2026 Shatz lawsuit signals costly talent theft battles and stricter recruiting scrutiny.
  • Citadel Securities’ second-quarter 2026 trading revenue slid 8.4% as volatility ebbed.
  • China licensing, Dubai expansion, and Miami’s $2.5 billion HQ create regulatory and execution risk through 2027.

What makes Citadel unique

  • Ken Griffin’s multistrategy platform produced July 2026 gains across Wellington, Tactical Trading, and equities.
  • Citadel Securities provides cross-asset liquidity; Reuters reported $12.2 billion trading revenue in 2025.
  • The firm moves fast on distressed opportunities, buying Situational Awareness’s portfolio in July 2026.

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Benefits

Health Insurance

Life Insurance

401(k) Retirement Plan

401(k) Company Match

Growth & Insights and Company News

Headcount

6 month growth

4%

1 year growth

4%

2 year growth

4%
Gizmodo
Aug 5th, 2026
AI-Powered 'vishing' attacks reportedly targeted top hedge funds.

AI-Powered 'vishing' attacks reportedly targeted top hedge funds. Turns out rogue AI isn't the only cybersecurity threat to be worried about. By Webb Wright Published August 5, 2026, 3:39 pm ET Reading time 2 minutes Amid all the recent reports of AI systems autonomously going off the rails and hacking into third-party organizations, it's almost easy to forget that human hackers are still out there, experimenting with AI in all kinds of nefarious ways. A new report from Bloomberg, however, is a reminder of just how quickly AI-enabled cybercrime is evolving - and how unprepared the world is to deal with it. According to the report, a litany of high-profile hedge funds, including Citadel and Two Sigma, were targeted by recent voice phishing, or "vishing," attacks, in which AI is used to simulate the voices of actual humans in an attempt to skirt security systems. Several private equity firms were also reportedly targeted. Two Sigma told Bloomberg it caught the attack in time before any of its internal systems were compromised. Citadel declined Gizmodo's request for comment. Point72, another hedge fund included in the attack, did not immediately respond to a comment request. IT experts have been warning for years that the proliferation of cheap, easy-to-use AI tools that mimic human speech or generate other kinds of deepfake content will escalate both the severity of scam attempts and the rate at which they occur. The world got a taste of this in 2024, when an employee at the Hong Kong branch of a multinational company was duped into wiring more than $25.5 million to scammers who had instructed her to do so using AI-generated deepfakes of company employees, including its chief financial officer. AI scams are also being deployed to tip political scales. Last summer, for example, someone (or a group of people working together) used AI to recreate the voice of Secretary of State Marco Rubio and then sent voice messages to foreign diplomats and federal officials. OpenAI also said in a June report that a fleet of scammers, all of whom appear to have been backed by the Chinese government, had been illicitly using ChatGPT to generate inflammatory social media content aimed at fueling Americans' resentment towards data centers, the power cells of the United States' AI industry. All the while, the market pressures of the AI race - combined with a total lack of federal regulation - have been pushing tech developers to build increasingly capable models, including ones designed to imitate human speech. (Such tools are often promoted as "companions" that can alleviate loneliness, even though research has indicated they can sometimes have the opposite effect.) OpenAI's latest voice model, GPT-Live-1, is engineered to imitate subtle nuances of human speech, and, in theory, make interacting with AI feel less awkwardly mechanical. By design, OpenAI's model cannot imitate the voices of real people; that was a lesson OpenAI had to learn the hard way after it received earlier public blowback for releasing a voice model that, to many people's ears, sounded a lot like Scarlett Johansson. This is all to say: Nobody should be surprised that vishing attacks are on the rise. Technologically-enabled scam artistry is a tale as old as time, and AI is arguably the most enabling tool ever invented in that regard. The real mystery is why more isn't being done to build actually effective safeguards into AI systems to prevent them from happening in the first place.

Taipei Times
Aug 3rd, 2026
Citadel's Griffin buys Situational Awareness fund after 67% AI stock loss

Citadel founder Ken Griffin purchased a portion of Situational Awareness's portfolio after the California hedge fund suffered a 67% loss in February from soured AI stock bets. The fund was forced to unwind most of its $16 billion public equities book. Griffin assembled senior Citadel executives who worked through the night to analyse Situational Awareness's trading positions and liquidity. By Thursday, Citadel had acquired part of the portfolio. Leopold Aschenbrenner, Situational Awareness's founder and former OpenAI researcher, told investors he took "full responsibility" for the losses. He said positions moved against the fund whilst market liquidity dried up. The acquisition follows Griffin's pattern of identifying distressed opportunities. Forbes estimates his personal fortune at approximately $52 billion. Representatives for both firms declined to comment on the transaction's financial terms.

The Edge Media Group
Jul 31st, 2026
Citadel buys most of Situational's stock holdings after AI share rout - Reuters

Citadel buys most of Situational's stock holdings after AI share rout - Reuters. 31 Jul 2026, 03:09 pm Citadel founder and CEO Ken Griffin. NEW YORK (July 30): Situational Awareness, an AI-focused hedge fund run by former OpenAI researcher Leopold Aschenbrenner, sold the bulk of its stock portfolio to Ken Griffin's Citadel after being battered by heavy losses in its tech holdings, two sources familiar with the matter told Reuters on Thursday. Situational was forced to unwind most of its public equities portfolio, which included sizable holdings in several prominent AI names that have been rocked by the recent market selloff, the sources said, requesting anonymity as the discussions are confidential. The fund was under pressure to either raise fresh capital from investors or offload its entire book, and eventually chose the latter option, the sources added. Situational held positions in several prominent tech names including Broadcom, Intel, and CoreWeave, according to its most recent regulatory filings. Since the fund's launch in 2024, Aschenbrenner has garnered a cult-like following among investors for his prescient bets on the AI sector that propelled his fund to a lofty 439% return from the start of the year until the end of June. The fund was down around 67% so far in July after incurring heavy losses on AI stocks, the Wall Street Journal reported on Thursday, citing a source who saw a letter the firm sent to investors. Aschenbrenner blamed short sellers who targeted the firm's positions for exacerbating losses, the report said. The firm did not immediately respond to Reuters request for comment outside business hours. A number of top Wall Street prime brokers, including Goldman Sachs, JPMorgan Chase, Bank of America, and Citigroup, helped facilitate the deal between Citadel and Aschenbrenner's fund, the sources told Reuters. Griffin's Citadel, which has about US$71 billion of assets under management, is one of the world's most profitable and largest hedge funds. As part of the deal, Citadel is picking up the portion of Situational's public portfolio that was financed by leverage from brokers, the sources said. They said Situational will hold a book of roughly US$10 billion after the deal comprised of stocks as well as private investments in companies like Anthropic. Situational has not sold its stake in Anthropic, the sources said. AI meltdown. Global hedge funds are grappling with their biggest monthly drawdown on record as AI stocks have been routed across the board, erasing much of the gains from crowded bets in the sector. Asia-focused fundamental long-short funds are down 18.6% on average this month through July 28, Goldman Sachs said in a prime brokerage note sent to clients this week. Stock-picking hedge funds have been rushing to unwind their positions in AI names, as they covered short positions and sold long positions in relatively equal amounts, according to a note from Morgan Stanley's prime brokerage unit sent to clients on Wednesday. Hedge funds typically take on large amounts of leverage from lenders to take bigger swings at the markets in order to amplify their returns. However, such leveraged bets can backfire when the markets move against positions taken by funds, forcing margin calls from prime brokers. That can result in a vicious cycle, where the margin calls trigger sales, extending market downturns that beget more selling. It is not clear whether Aschenbrenner's fund faced margin calls from its lenders before striking the deal with Citadel. The hedge fund, which earlier managed about US$20 billion of assets and currently has about 20 employees, has used leverage to boost its positions in the past - much like its peers. Aschenbrenner's success attracted big-name backers like secretive trading giant Jane Street. Other investors include Stripe co-founders Patrick and John Collison, as well as Meta Platforms executives Daniel Gross and Nat Friedman. The Wall Street Journal reported the deal between Citadel and Situational earlier on Thursday. Uploaded by Liza Shireen Koshy

Divito Real Estate Group
Jul 22nd, 2026
South Florida's top deals Palm Island home sells for $19M.

South Florida's top deals Palm Island home sells for $19M. From an eight-figure Palm Island waterfront sale to a billionaire moving a century-old Brickell landmark - South Florida's top end stays busy. South Florida's high end doesn't take the summer off. In the latest roundup of the region's most notable transactions, a Palm Island waterfront home traded for $19 million, and one of the world's wealthiest people made a bold move on a piece of Miami history. Here's a look at the headline deals - and what they say about the market. Palm Island waterfront sale Age of Brickell's Dr. Jackson building South Florida still in demand Palm Island home sells for $19 million. According to The Real Deal, a waterfront property at 288 South Coconut Lane on Palm Island - one of Miami Beach's exclusive guard-gated island enclaves - sold for $19 million. The home has been publicly linked to boxing champion Floyd Mayweather Jr. An eight-figure sale on a private island underscores how much appetite remains for trophy waterfront in South Florida, even as the broader market normalizes. Ken Griffin's plan for a century-old Brickell landmark. In Brickell, billionaire Ken Griffin - founder of Citadel, which is building a major new headquarters in the neighborhood - aims to relocate the historic Dr. Jackson building, a structure that has stood in Brickell for nearly 110 years, according to the South Florida Business Journal. Rather than demolish it, the plan would move the landmark to another part of Miami, a rare and expensive way to preserve history amid one of the country's most active development corridors. Free · No Obligation Curious about South Florida's luxury market? Leave your info and a Divito Real Estate agent will send current listings and an honest read on values in your target neighborhood - free. What these deals tell Divito Real Estate Group about the market. * Ultra-prime demand is intact. A $19M private-island sale signals that the very top of the South Florida market - waterfront, gated, irreplaceable land - still commands premium prices. * Capital keeps flowing into Miami. Griffin's continued Brickell investment (and willingness to move a landmark to build) is a vote of confidence in the market's long-term trajectory. * Trophy assets behave differently. While everyday buyers weigh 6.5% mortgage rates, the top of the market runs largely on cash and conviction - which is why luxury headlines keep coming. What it means for buyers and sellers. You don't need $19 million to take a lesson from these deals. South Florida's enduring demand - from relocators, second-home buyers, and international capital - is exactly what supports values across price points, from Brickell condos to Treasure Coast single-family homes. If you're buying, understand what's driving your specific neighborhood; if you're selling, know that the right pricing and positioning still win, at every level. The bottom line. Blockbuster deals like a $19M Palm Island sale and a billionaire relocating a Brickell landmark are more than gossip - they're signals that South Florida remains a magnet for people and capital. That demand is the foundation under the whole market. Whatever your price range, a local agent who tracks these moves can tell you what they mean for your street. Divito Real Estate Group South Florida & Treasure Coast Real Estate - Editorial Team Divito Real Estate Group serves buyers, sellers, and investors from Miami to the Treasure Coast. Divito Real Estate Group track the Florida market so its clients can make confident, fully-informed decisions. Thinking about a South Florida move? Get a free, no-obligation read on luxury and waterfront values in your target area. Frequently asked Questions. What sold for $19 million in South Florida? A waterfront home at 288 South Coconut Lane on Palm Island in Miami Beach sold for $19 million, according to The Real Deal. The property has been publicly linked to Floyd Mayweather Jr. What is Ken Griffin planning in Brickell? Per the South Florida Business Journal, Griffin aims to relocate the historic Dr. Jackson building - nearly 110 years old - to another part of Miami rather than demolish it, as Citadel builds a major Brickell headquarters. Is South Florida's luxury market still strong? High-profile trophy sales suggest the top end remains in demand, driven largely by cash buyers and international capital that are less sensitive to mortgage rates than the broader market. How do luxury deals affect regular buyers and sellers? They reflect the deep, durable demand that supports South Florida values across price points. Local pricing and positioning still determine outcomes at every level. Related reading. Free Florida Real Estate Calculators Run your numbers before you tour a single home - free, instant, no signup. Free · No Obligation Talk to a Divito Real Estate agent. Questions about buying or selling in Florida? Leave your info and Divito Real Estate Group'll reach out - free, no pressure.

Associated Press
Jul 17th, 2026
FreeCast's SEC filing reveals institutional backing from Citadel, Davidson Kempner and Weiss

Parallax Trust has highlighted FreeCast's recent SEC filing, which reveals participation by several institutional investors including Citadel CEMF Investments Ltd, Davidson Kempner, and Weiss. The filing identifies these firms in connection with FreeCast's disclosed financing transactions. FreeCast, which trades on Nasdaq under ticker CAST, has developed a streaming television Platform-as-a-Service ecosystem over the past decade. The company's platform spans consumer streaming, telecommunications, broadband providers, and digital advertising. Parallax Trust notes that whilst the filing shouldn't be interpreted as an institutional endorsement, the presence of recognised institutional participants in a public company's capital structure is often viewed as noteworthy by the investment community. Parallax Trust is an early-stage investor in FreeCast.