Principal Engineer

PeopleFun is an award-winning creator of mobile games for players across the globe. PeopleFun is a Dallas-based game studio founded and led by game industry veterans, where game developers thrive on collaboration, creativity, teamwork, and fun. Our games are played by over 25 million players each month, and we have a number of exciting mobile games in development to fuel the future growth of PeopleFun. We believe in bringing People together through Fun by creating the best in class social features and communities in our games that enables our players to engage deeply with other players. Secondly we endeavor to bring our studio teammates together by creating the very best game teams that foster healthy collaboration, incredible productivity, and life-long professional relationships. Candidates who reside or will reside in the following locations are eligible for this role: California, Colorado, Florida, Georgia, Illinois, Maryland, Massachusetts, Minnesota, Nevada, New Hampshire, New Jersey, Oregon, Rhode Island, Texas, and Washington State. Job Summary PeopleFun is actively seeking a highly skilled and innovative Principal Engineer to lead the development of our pioneering dynamic difficulty system, WordAlgo. This critical role involves optimizing the player experience by dynamically adjusting game difficulty in real-time, leveraging initial rule-based algorithms, and subsequently integrating advanced Machine Learning and Large Language Models. The impact of this work will extend across multiple mobile word puzzle games within our portfolio, significantly enhancing player engagement and retention. Reporting to a General Manager with a strong engineering background, the successful candidate will operate within a collaborative, agile team comprising a data scientist and a data engineer. This environment emphasizes iterative development, A/B testing, and continuous evaluation of innovative solutions. We are looking for a professional with a proven track record in challenging technical domains, a proactive approach to problem-solving, and a passion for creating highly engaging mobile game experiences. This position offers a unique opportunity to contribute to a transformative initiative within a fast-paced and forward-thinking organization. Responsibilities Design, develop, and implement the core Word Algorithm (WordAlgo) system, initially focusing on rule-based logic and evolving into ML and LLM-driven solutions using unit tests Create tools to convert and generate optimized data for use in mobile games. Collaborate closely with data engineers and data scientists to integrate data pipelines and leverage player data for difficulty detection and adjustment. Work hand-in-hand with game development teams to seamlessly integrate WordAlgo into existing and new mobile games, ensuring a clean and well-documented API for game logic to consume. Design and document technical specifications for WordAlgo components, including algorithm logic, data flow, and API contracts. Participate actively in an Agile development environment, contributing to iterative design, implementation, and testing cycles. Continuously monitor and analyze game performance data to identify opportunities for algorithm optimization and player experience improvement. Articulate technical concepts, challenges, and solutions clearly and concisely to both technical and non-technical stakeholders through verbal and written communication. Champion PeopleFun's culture of trust, humility, and team-focused results in all aspects of work. Requirements 7+ years of experience in mobile game development, with a strong understanding of game architecture and systems. Demonstrated experience successfully launching and operating at least one commercial mobile game title. Expert-level proficiency with Unity game engine, including a deep understanding of its architecture, scripting (C#), and best practices. Proven ability to design and implement robust, scalable, and well-documented APIs. Excellent verbal and written communication skills, with the ability to articulate complex technical ideas and engage in productive discussions. Experience writing comprehensive technical design documents. Familiarity with Agile development methodologies and a track record of delivering iteratively. Preferred Qualifications Experience with or a strong understanding of Machine Learning concepts and applications. Familiarity with Unity Sentis or similar on-device ML inference engines. Experience working with large datasets and data-driven systems. Knowledge of Natural Language Processing (NLP) or Large Language Models (LLMs). PeopleFun provides a competitive total compensation package with a pay-for-performance rewards approach. The expected base pay range for this [CA-based or North America-based] position is $120,000–$206,250. Compensation is based on factors including market location and individual qualifications. Depending on the position offered, equity, sign-on bonuses, and other compensation may be included as part of the total package. Benefits Medical/Dental/Vision Insurance Performance Bonuses 401K Match Policy Flexible PTO Policy Wellness Stipend Free Lunch each Friday Generous ParentalLeave & Family-Friendly Culture Annual Credits for Professional Development & In-App Purchases PeopleFun is proud to be an equal opportunity employer that is committed to inclusion and diversity. All applicants will be considered for employment without attention to race, color, religion, sex, sexual orientation, gender identity, national origin, veteran or disability status, or other legally protected characteristics. Learn more about EEO rights as an applicant here .