Infrastructure Business Operations Associate in Belgrade

Perplexity is seeking an experienced Machine Learning Engineer to advance how AI systems search, reason, and work together to solve complex problems. Our work spans search and retrieval, LLM post-training, multi-agent training, and the harnesses that make these systems effective. We control the full stack: the models, the agent harnesses, and the search infrastructure underneath. That gives us the freedom to develop new approaches across all three training models to use search more effectively, designing tools and execution environments around learned behavior, and improving retrieval to support how agents actually work. Responsibilities Push search and agent quality forward through improvements to models, training data, tools, and system design. Develop LLM post-training methods, including reinforcement learning, to improve reasoning, search, tool use, and task completion. Train and evaluate multi-agent systems, exploring how agents divide work, share information, and coordinate effectively. Design and build agent harnesses around the tools, context management, execution environments, and orchestration that support reliable work over many steps. Improve retrieval and ranking models and the search interfaces agents use to find and assess information. Build datasets, reward signals, and evaluations that expose meaningful failures and guide improvements. Own experiments end to end, from a clear hypothesis to scalable training, deployment, and measurable gains in quality, latency, and cost. Collaborate with AI, Search, Infrastructure, Data, and Product teams to bring new capabilities into production. Qualifications A strong track record of building and shipping ML systems, with deep experience in one or more of LLM post-training, reinforcement learning, search and retrieval, or agent systems. Strong software engineering skills and the ability to work across model training, experimentation infrastructure, and production systems. Experience designing rigorous evaluations

Perplexity is seeking an experienced Machine Learning Engineer to advance how AI systems search, reason, and work together to solve complex problems. Our work spans search and retrieval, LLM post-training, multi-agent training, and the harnesses that make these systems effective. We control the full stack: the models, the agent harnesses, and the search infrastructure underneath. That gives us the freedom to develop new approaches across all three training models to use search more effectively, designing tools and execution environments around learned behavior, and improving retrieval to support how agents actually work. Responsibilities Push search and agent quality forward through improvements to models, training data, tools, and system design. Develop LLM post-training methods, including reinforcement learning, to improve reasoning, search, tool use, and task completion. Train and evaluate multi-agent systems, exploring how agents divide work, share information, and coordinate effectively. Design and build agent harnesses around the tools, context management, execution environments, and orchestration that support reliable work over many steps. Improve retrieval and ranking models and the search interfaces agents use to find and assess information. Build datasets, reward signals, and evaluations that expose meaningful failures and guide improvements. Own experiments end to end, from a clear hypothesis to scalable training, deployment, and measurable gains in quality, latency, and cost. Collaborate with AI, Search, Infrastructure, Data, and Product teams to bring new capabilities into production. Qualifications A strong track record of building and shipping ML systems, with deep experience in one or more of LLM post-training, reinforcement learning, search and retrieval, or agent systems. Strong software engineering skills and the ability to work across model training, experimentation infrastructure, and production systems. Experience designing rigorous evaluations

We're building the future of Speech Intelligence at Speechmatics, and we need someone who can own the technical engine behind how customers discover, adopt, and grow with our platform. This is a hands-on backend engineering role, where your work directly shapes the journey from a customer's first interaction with our website to their first meaningful moment of value. If you thrive shipping, iterating, and making a measurable commercial difference, then we’d love to hear from you. What you'll do Own the backend development and ongoing health of the Speechmatics website and self-serve portal Build and maintain new custom components from scratch, turning design specifications into reliable, performant, production-ready code Manage Vercel deployments and backend infrastructure, keeping the live site fast, stable, and technically sound Implement UI design changes end-to-end, bridging the gap between what's designed and what goes live Write Python-based queries to surface insights across the self-serve portal and support data-driven decisions across the growth team Identify and act on opportunities to improve conversion across the self-serve funnel through well-timed, well-designed product experiences Collaborate closely with product, design, and data teams in a cross-functional, async-friendly way, working closely together to remove blockers and unlock opportunities Own the ongoing improvement of site performance, loading speed, and technical reliability What you'll need Proficiency in JavaScript and TypeScript for website backend development, with a track record of shipping and maintaining production code Hands-on Python experience, particularly for data queries Demonstrable experience with LLM and AI-first development workflows, tools like Claude, Cursor, or similar Experience in a product-led growth or self-serve SaaS environment, with a clear understanding of conversion funnels and how engineering choices affect them The ability to o

Perplexity is seeking an experienced Machine Learning Engineer to improve search quality across the middle and later stages of ranking. We are looking for a strong ranking generalist who can own ambiguous problems end to end and brings exceptional depth in either neural ranking or production ranking systems. Responsibilities Push search quality forward through models, data, evaluation, infrastructure, or any other leverage available. Own ranking-quality problems end to end: define the evaluation, identify the bottleneck, build the solution, and ship it safely. Train and evaluate retrieval, ranking, and classification models, including neural and LLM-based approaches where appropriate. Build and operate ranking infrastructure, including feature computation, low-latency inference, multi-stage cascades, deployment, and monitoring. Make sound trade-offs across quality, latency, reliability, cost, and engineering complexity. Collaborate across Data, AI, Infrastructure, and Product while retaining ownership of the final quality outcome. Qualifications Deep understanding of search or recommender systems and their evaluation. Proven ownership of a large-scale production ranking system or a substantial class of quality problems. Strong machine learning and software engineering skills across data, models, serving, and monitoring. Ability to drive ambiguous, cross-team problems without continuous task decomposition. Exceptional depth in either modern neural ranking methods or low-latency ranking systems and runtime.

DeepIntent is the leading healthcare marketing platform, purpose-built to help marketers plan, activate, and optimize data-driven campaigns with speed and precision. Trusted by the world’s top healthcare brands and their agencies, DeepIntent uniquely unites media, identity, and real-world clinical data to power privacy-safe, omnichannel marketing across every screen. Backed by patented technology and proven outcomes, DeepIntent’s platform delivers measurable audience quality and script lift at scale. Learn more at www.deepintent.com . Location: Banja Luka, Bosnia and Herzegovina (primary) or Belgrade, Serbia What You’ll Do: As a Senior Security Engineer, you will own the security architecture and enforcement across our infrastructure. Our infrastructure relies heavily on a Linux ecosystem, and as we scale our cloud footprint and AI initiatives, this layer is becoming increasingly security-sensitive. You will be embedded directly with the teams operating these systems, bridging the gap between high engineering velocity and secure-by-design architecture. Your core mandate is to protect production, harden our Linux environments, establish AI guardrails, and build secure access patterns without creating process overhead. This role will report to the Sr Director, Infrastructure and Networking and will be a hybrid role based out of Banja Luka, Bosnia. Linux Hardening & Threat Detection: Secure our underlying Linux infrastructure and container runtimes. Deploy, tune, and manage our SIEM for continuous threat detection, file integrity monitoring, and host-based intrusion detection (HIDS) across our fleet. Identity & Access Control: Design and enforce secure access patterns. Ruthlessly eliminate shared accounts, long-lived credentials, and overly broad permissions across the organization. Cloud & Infrastructure Governance: Own the security posture across our cloud environments. Implement secure infrastructure-as-code practices using Terraform an

We are seeking an experienced Backend Software Engineer to join our Crawler team. In this role, you will design, develop, and operate systems that ingest, process, and manage web-scale data in support of our next generation of advanced search technologies. This is a critical, high-impact engineering position, requiring expertise across both backend and frontend components of our data acquisition stack. Responsibilities Take ownership of and lead projects focused on developing large-scale web crawlers, ingestion pipelines, and data processing systems. Build, maintain, and optimize core backend and frontend components for crawler services, including storage, retrieval, and UI dashboards for data management. Collaborate closely with Search and Infrastructure teams to ensure the reliable, high-quality ingestion and processing of billions of web pages. Architect and implement fullstack features and scalable distributed systems that handle high-load and real-time data operations. Rapidly iterate, experiment with novel approaches, and continuously enhance system performance, usability, and reliability. Qualifications Minimum of 5 years of software development experience, with strong knowledge of data structures and algorithms in at least one of the following languages: Python, C++, Rust, or Go. Experience with large-scale web crawlers is highly desirable. Proven experience building, deploying, and optimizing high-load, distributed, and hardware-adjacent services. Deep understanding of cloud infrastructure, with hands-on experience in Kubernetes (K8s) and AWS. Demonstrated passion for writing clean, efficient, and scalable systems.

Perplexity is seeking an experienced Machine Learning Engineer to help build the next generation of advanced search technologies, with a focus on retrieval and ranking. Responsibilities Relentlessly push search quality forward—through models, data, tools, or any other leverage available Architect and build core components of our search platform and model stack Train and evaluate retrieval, ranking and classification models, including LLMs Deploy models - from boosting to LLMs - in a scalable and performant way Build and optimize RAG pipelines for grounding and answer generation Collaborate with Data, AI, Infrastructure and Product teams to ensure fast and high quality delivery Qualifications Deep understanding of search and retrieval systems, including quality evaluation principles and metrics Proven track record with large-scale search or recommender systems Self-driven, with a strong sense of ownership and execution Minimum of 5 years of working on search or recsys-related projects

Job Overview Wargaming is looking for a proactive and hands-on Facility Officer to join our team in Belgrade. In this role, you will help ensure that our office facilities are safe, functional, and well-maintained, supporting smooth day-to-day operations and providing a comfortable working environment for our employees. You will be responsible for carrying out basic maintenance tasks, monitoring the condition of office facilities and equipment, coordinating external contractors and service providers, and assisting with workspace arrangements and office logistics. This role is ideal for someone who enjoys practical work, takes initiative, and can efficiently handle a variety of facility-related tasks. Reports to Head of Workplace & Employee Experience What will you do? Assists with maintaining daily operations of the physical facility. Supports maintenance mechanics and facilities staff by performing “handyman” maintenance duties such as furniture moves, simple electrical projects Works with outside contractors on building and equipment repairs Operates site equipment as needed, using hand and power tools as necessary Coordinates vendors/employees for performance of specialized maintenance, repair, or certification of buildings, infrastructure, tech appliances. Inspects completed work for conformance with contract requirements and safety codes Performs regular checks of buildings, infrastructure, and premises to ensure safety and uninterrupted use Organize storage areas, inventory management Providing support to office team in everyday operations: assist with setting up workspaces for new employees Arrange furniture and office equipment as needed Provide logistical support for meetings, events, and office functions What are we looking for? Previous experience in facility maintenance, handyman services, technical support, or a similar hands-on role. Practical skills in basic

Job Overview Wargaming is looking for a Performance QA Team Lead to join our World of Warships PC team. In this role, you’ll lead the Performance QA team, drive performance testing and automation using Python, and help ensure the game delivers a smooth and stable experience for players. We’re looking for a technical leader with a strong and broad background in performance engineering, who can combine hands-on expertise with team leadership and help us continuously improve our performance testing practices. Reports to Head of QA What will you do? Lead the Performance QA team: task planning, coordination, mentoring, and technical guidance Define and maintain performance testing strategy, coverage, baselines, thresholds, and regression criteria Investigate performance regressions, identify bottlenecks, and drive root-cause analysis across client, backend, and system-level components Drive performance testing and automation across game client, backend services, network interactions, and system-level scenarios Create and maintain test infrastructure, tools, and frameworks for QA team Maintain documentation for performance tests, tools, and testing processes Collaborate with development and other teams to analyze performance results and drive improvements Integrate and maintain performance testing within CI/CD pipelines Participate in architectural and technical design reviews from a QA perspective What are we looking for? 4+ years of experience in Performance QA, Performance Engineering, or related areas Experience in leading QA teams or technical leadership 2+ years of professional experience with Python Strong understanding of performance engineering principles and the ability to investigate performance issues across complex systems Experience in at least one of the following areas: client performance, backend/load performance, distributed systems, or system-level performance analysis Upper-Interme

Perplexity is looking for a Search Machine Learning Engineer Intern to help build the next generation of advanced search technologies, with a focus on retrieval and ranking. You will work closely with experienced engineers to improve search quality, experiment with new models, and ship features that directly impact how users search and discover information. Internship program: 12 - 24 weeks, full-time, part-time, in-person in the Belgrade office. Responsibilities: Contribute to experiments that improve search quality through better models, data usage, and evaluation tools, under the guidance of senior engineers. Design and implement components of the search platform and model stack, including retrieval, ranking, and classification models. Train evaluating models (including LLM-based approaches) for retrieval, ranking, and classification tasks. Support deployment and monitoring of search and ranking models in a scalable and performant way. Help build and iterate on RAG pipelines for grounding and answer generation. Collaborate with Data, AI, Infrastructure and Product teams to deliver improvements quickly and learn best practices in production ML. Qualifications: Strong foundation in machine learning and statistics, with coursework or projects related to information retrieval, ranking, or recommender systems. Experience with Python and common ML frameworks (e.g. PyTorch, TensorFlow, JAX) through academic, open source, or personal projects. Familiarity with evaluating model quality using offline metrics and/or A/B testing is a plus, but not required. Previous experience (internships, research, or significant projects) working on search, recommendation, or NLP is a plus, but not required. Self-driven and curious, with a strong sense of ownership, willingness to learn, and comfort working in a fast-paced environment Experience with Rust will be a plus What we're looking for: You’ve built something you’re proud of: Not just a class assignment - we want to see a project y

Perplexity is looking for a highly skilled Senior or Expert Systems Engineer to join our Search Core team. This role is critical to building next-generation search products and technologies. You will help drive key decisions around the architecture, design, and implementation of foundational components in our technical stack. Responsibilities Design and build core search engine components, including indexing pipelines, retrieval algorithms, and ranking systems that operate at the scale of billions of pages Develop streaming and batch data processing systems for search index construction in a high-load environment Push the limits of hardware performance through low-level optimizations and systems-level tuning Tackle challenges in multithreading, concurrency, and system-level optimization Qualifications 3+ years of hands-on experience in systems programming (Rust, C++, C, or similar) Ownership of full project lifecycle — you don't just write a fast inner loop, you care about how the system is built, deployed, operated, and scaled in production Knowledge of Python or other scripting languages Passion for writing clean, efficient, and scalable systems-level code Strong knowledge of algorithms and data structures, and the ability to apply them effectively Deep understanding of multithreading, including various approaches, challenges, and trade-offs Experience building high-load, distributed, and hardware-adjacent services Solid understanding of Linux internals (syscalls, networking stack, memory model, kernel tuning) Familiarity with low-level optimization techniques (memory management, cache efficiency, SIMD, profiling) Preferred Qualifications Experience developing core components of search engines, databases, or information retrieval systems Understanding of search fundamentals: indexing, query parsing, ranking, and relevance Experience with trading systems or other latency-sensitive real-time systems Familiarity with cloud services, Kubernetes, and AWS infrastructure