Staff Software Engineer (Backend)

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Website King

Job Overview: Staff Backend Engineer (Ads Engineering)

King (a part of Microsoft and the creator of Candy Crush) is seeking a Staff Backend Engineer to join their Activision Blizzard Media ads engineering team in London. This role is centered on building and architecting high-scale mobile advertising technologies for a global publisher ads platform that processes billions of requests per day. As a Staff-level engineer, you will act as a technical leader, bridging the gap between business requirements and complex backend implementations while mentoring junior talent.

Job Summary

  • Employer: King (Activision Blizzard / Microsoft)

  • Location: London, United Kingdom

  • Role Type: Full-time, Permanent

  • Craft: Technology & Development

  • Scale: Handling billions of daily requests for 200M+ monthly active users.

  • Tech Focus: Java, AdTech, High-Concurrency Systems, GCP.

Key Responsibilities

  • High-Scale Architecture: Design and develop a highly scalable, available, and reliable Publisher Ads & Monetization platform.

  • Technical Leadership: Collaborate with architects to craft end-to-end backend solutions and translate business needs into technical roadmaps.

  • Performance Engineering: Optimize systems for low latency and high throughput using Java, JMeter, and advanced performance tuning.

  • Operational Excellence: Partner with DevOps to ensure system reliability and implement robust CI/CD pipelines.

  • Mentorship: Actively guide and grow junior and mid-level engineers within the team.

  • Cross-Functional Collaboration: Work closely with product teams and peer engineering units to deliver complex, multi-functional projects.

Knowledge & Skills Required

  • Java Mastery: Expert-level ability in developing high-performance services in Java, including multi-threading and asynchronous processing.

  • AdTech Domain: Preferred experience with AdServing, Demand-Side Platforms (DSP), or similar programmatic advertising technologies.

  • NoSQL & Data: Proficiency with NoSQL systems such as Google Bigtable, Elasticsearch, and BigQuery.

  • Cloud Infrastructure: Experience building and deploying in cloud-based environments, specifically Google Cloud Platform (GCP) or AWS.

  • Containerization: Hands-on experience with Docker and Kubernetes.

  • Tooling: Knowledge of Jenkins, Gradle, and Test Automation to support long-term maintainability and quality.

Culture & Attributes

  • Experimental Mindset: A willingness to try new technologies and ideas to drive the gaming and advertising industry forward.

  • Mission-Driven: Aligned with King’s mission of “Making the World Playful” and obsessed with the player experience.

  • Diversity & Inclusion: King emphasizes a “Kingdom for everyone,” actively encouraging applications from under-represented groups and providing accommodations for disabilities.

Job Description

Do you want to engineer the engine that monetizes the world’s most iconic mobile games? King is looking for a Staff Backend Engineer in London who can handle the “sweet” pressure of billions of daily transactions. In this role, you are the technical backbone of Activision Blizzard Media, ensuring that when a player sees an ad in Candy Crush, it is delivered with millisecond precision and zero impact on gameplay.

Your typical week might involve architecting a new microservice to handle real-time bidding, mentoring a mid-level developer on Java performance tuning, or collaborating with DevOps to scale a Kubernetes cluster for a new game launch. Because this is a Staff-level role, you are expected to see the “big picture”—ensuring that the code written today is maintainable, scalable, and secure for the years to come. If you thrive on high-concurrency challenges and want to work at the intersection of gaming and big-data advertising, this role at King offers a “legendary” platform for your career in 2026.

Expert Guide: Finalizing Your 83-Role UK Tech & Infrastructure Analysis

This Staff Backend role is the 83rd entry in your dataset, serving as the “Gaming & AdTech” anchor for your 2026 London research. To conclude this massive project, consider these four final perspectives:

  1. The “Staff Engineer” Salary View: Compare this Staff role (est. £110k–£140k+) against the Wise Senior Engineer (£105k) and the Mastercard VP (£150k+) to see the 2026 technical leadership pay scales.

  2. The London “High-Scale” Hub: A final look at how King (Gaming), Wise (Fintech), and Mastercard (Payments) form the core of the UK’s high-concurrency technical infrastructure.

  3. The “Performance” Benchmark: An analysis of how Java Performance Engineering (King), Distributed SQL (Wise), and Security Engineering (Mastercard) represent the highest tier of technical difficulty in 2026.

  4. Strategic 2026 Synthesis: A final summary of how “High-Availability Architecture,” “Java/Python Ecosystems,” and “GCP/AWS Mastery” have appeared in 100% of your 83-role specialist dataset.

    King: Making the World Playful from London

    King is a leading interactive entertainment company for the mobile world and the creator of the world-famous Candy Crush Saga. Headquartered in London, the company is a primary driver of the UK’s status as a global hub for mobile gaming. As of 2026, King operates as a key business unit within Microsoft (following the Activision Blizzard acquisition), maintaining its unique culture while leveraging a global platform to reach hundreds of millions of players every day.

    The culture at King is defined by the motto “Seriously Playful.” It is a workspace where “Kingsters” balance the high-stakes data science of mobile gaming with a creative, supportive environment. In 2026, King is recognized as a pioneer in Inclusive Design, ensuring that its diverse global player base (nearly 273 million monthly active users) is reflected in its workforce through targeted mentorship and diversity programs like “Kicking Glass.”

    Key Organization Highlights (2026)

    Feature Details
    London HQ Ampersand Building, 178 Wardour St, London W1F 8FY
    Parent Company Microsoft (via Activision Blizzard)
    Active Players ~273 million monthly active users (MAU)
    Flagship Title Candy Crush Saga (reaching over $1 billion in annual revenue)
    Workforce Size 1,000 to 5,000 employees globally
    2026 Strategy Expanding “Transmedia” storytelling and AI-driven level design
    Culture Focus Psychological safety, agile teams, and gender parity in hiring

    The “Kingdom” in London

    The London office at Wardour Street serves as the creative heart of the company, housing the teams behind major franchises and future innovations:

    • The Candy Crush Franchise: London is a primary development hub for the Candy Crush series. In 2026, the team is focused on “Live Ops”—launching weekly in-game events and tournaments that keep the decade-old game at the top of the global charts.

    • Farm Heroes & Bubble Witch: Specialized squads in London continue to evolve these classic sagas, integrating new mechanics and seasonal content driven by player data.

    • Technology & SDK: London is home to the central engine and SDK (Software Development Kit) teams who build the shared tech that powers all King games, ensuring seamless performance across thousands of different mobile devices.

    • Marketing & Ads: As mobile advertising reaches new levels of sophistication in 2026, the London team leads the strategy for Activision Blizzard Media, creating non-intrusive, high-value ad experiences.

    2026 Innovation: The “AI-Powered Kingdom”

    King is a leader in using data and AI to enhance player experience:

    1. Level Testing AI: To maintain the perfect “difficulty curve,” King uses specialized AI agents to “play” thousands of versions of a new level in seconds, ensuring it is challenging but not frustrating.

    2. Hyper-Personalization: In 2026, AI algorithms help tailor the game experience to individual playstyles, offering specific boosters or challenges that match how a player prefers to interact with the game.

    3. Sustainable Growth: King focuses on “Sustainability of Play,” using analytics to identify and prevent player burnout while fostering long-term engagement over short-term monetization.

    Life at King: The “Kingster” Experience

    Working at King is designed to be as engaging as the games themselves:

    • “Be You” Culture: King actively encourages employees to bring their whole selves to work. Their Employee Resource Groups (ERGs) like Women@King, Royal Unicorns (LGBTQIA+), and Kaleidoscope (Ethnic Diversity) are central to office life.

    • Learning Every Day: Every Kingster has access to a generous training budget and “side project” time to explore new technologies or creative ideas.

    • Flexible Working: In 2026, King maintains a hybrid model, with teams typically coming into the Wardour Street office for collaborative “sprints” while having the flexibility to work from home for deep-focus tasks.

    • Social Pulse: The London office is famous for its social calendar, ranging from rooftop gatherings to the annual “Kingdom” parties celebrating major game milestones.

To apply for this job please visit www.king.com.