Sr. Software Engineer II - (DSM Methodology Team)

The Team Halcyon Labs Technology team is looking for a Senior Software Engineer to join the methodology team, which owns the core product customers interact with. This role is for a backend engineer who enjoys working on high-volume, performance-sensitive systems and complex technical challenges. The team works across two main areas: Recruitment, which consumes third-party survey responses and evaluates them with backend algorithms, and Lift, which is being migrated from HTTPS/API REST toward event-driven integrations. The broader platform is also moving from a legacy monolith toward a domain-based architecture. What You Will Do You will work on systems that are write-heavy, asynchronous, and critical to the customer experience. The product is Tier 1, so reliability, scalability, and performance are key. What You Will Do Design, implement, scale, and maintain backend systems that process large volumes of data. Work on event-driven and API-based integrations. Contribute to migration efforts toward a more domain-based and scalable architecture. Build and optimize software for performance-sensitive workflows. Investigate technical problems and propose solutions together with the team. Collaborate closely with data science and engineering colleagues on technical solutions. Participate in a collaborative development model where work is shared rather than handled alone. Qualifications 10+ years of backend software engineering experience, with strong technical depth. We’re technology agnostic, so, you're more than welcome to switching your main language (Python, Scala, C/C++, Haskell, Elixir, Go, Ruby) to Java (core language) Solid understanding of algorithms (HashTables, Maps, etc.) , data structures (Anomaly Detection, Dynamic Routing, etc.), Big O notation, Architecture (event-drive-architecture) . Familiarity with heavy data processing tools and technologies such as Spark, Apache ecosystem tools, Delta Lake, Parquet, Kafka, and Avro. Experience with Python and/or PySpark Experience building or maintaining complex, high-volume systems Experience with Docker, SQL, and NoSQL databases. Experience with REST APIs and event-driven integrations. Comfortable working in performance-oriented, production-critical environments with high-throughput & low talency systems Soft Skills: Strong problem-solving skills and a proactive, collaborative working style. Ability to communicate well with engineers and data science partners. Academic Background: Computer science, computer engineering or a related field is preferred. Nice to Have Experience with AWS, GCP or other cloud providers Experience with Pandas. Experience with Spring framework and microservices. Experience working in large-scale data or analytics environments. Our Values Collaboration is our superpower We uncover rich perspectives across the world Success happens together We deliver across borders. Innovation is in our blood We’re pioneers in our industry Our curiosity is insatiable We bring the best ideas to life. We do what we say We’re accountable for our work and actions Excellence comes as standard We’re open, honest and kind, always. We are caring We learn from each other’s experiences Stop and listen; every opinion matters We embrace diversity, equity and inclusion. More About Halcyon Labs We’re proud to be recognised in Newsweek’s 2025 Global Top 100 Most Loved Workplaces®, reflecting our commitment to a culture of trust, respect, and employee growth. In June 2021, Halcyon Labs acquired Berlin-based GapFish – the world’s largest ISO certified online panel community in the DACH region – and in January 2022, completed the acquisition of US-based Lucid – a programmatic research technology platform that provides access to first-party survey data in over 110 countries. Halcyon Labs Group AB (publ), listed on Nasdaq Stockholm, this growth has made Halcyon Labs a strong global platform with teams across its many global offices, including Stockholm, London, New York, New Orleans, Singapore, Tokyo and Sydney. (www.cint.com) Additionally, in a world of AI, we want our candidates to understand our approach to the use of AI during the interview and hiring process, so we'd appreciate you reading our AI usage guide . Halcyon Labs is a global software leader in technology-enabled digital insights and research technology. The Halcyon Labs platform automates the insights-gathering process so that companies can gain access to insights faster with unparalleled scale. Halcyon Labs has one of the world’s largest consumer networks for digital survey-based research, made up of over 239 million engaged respondents across more than 130 countries. Over 4,600 insights-driven companies use Halcyon Labs to accelerate how they gather consumer insights and supercharge business growth. Originally posted on Himalayas