Cast AI is hiring a Senior Software Engineer for the Platform team to design, build, and operate CI/CD pipelines, observability tooling, and local development environments used by internal engineering teams. The role prefers production experience in Go, strong systems programming skills, and hands-on experience with Kubernetes, GitOps/CI tooling, Terraform, cloud platforms (AWS/GCP/Azure), and observability stacks. This remote-first, location-specific role accepts applicants residing in Bulgaria, Croatia, Estonia, Greece, Hungary, Latvia, Lithuania, Poland, Romania, Slovakia, Slovenia, and Ukraine.

Work on a 0→1 engineering team building AI-powered agent systems that interact with internal systems to automate workflows and decision paths. Responsibilities include designing and implementing inference pipelines, architecting backend services that integrate with multiple internal APIs and data sources, prototyping and productionizing agent behaviors, and defining patterns for safe, observable, and controllable agent execution. Role requires 5+ years building and shipping production software with strong backend fundamentals and hands-on experience with AI/ML or LLM-based systems.

Wikimedia Foundation seeks a Senior Software Engineer, iOS on a 3-month full-time contract to work on the App Growth team. Responsibilities include delivering medium-complexity initiatives end-to-end, system design, improving the iOS Wikipedia app, instrumentation for observability, and cross-functional collaboration. Requires a bachelor's degree and 5+ years professional experience building iOS apps with strong proficiency in Swift, SwiftUI, and UIKit. Role is fully remote but requires at least four hours of each workday between 14:00 and 21:00 UTC. Hiring is currently open in a specified list of countries.

MariaDB is hiring a Senior Java Software Engineer to design, implement and optimize a geo-distributed, high-performance database (replication, sharding, concurrency, HA). Role involves leading engineers, debugging and profiling Java applications, and working with on-premise and cloud environments. Location: hybrid/remote across specified European countries. Salary range €74,200–€90,000/year. MariaDB does not sponsor work visas or relocation.

Work on the Firefox DOM Core team to improve Session History test coverage and Gecko correctness. Responsibilities include writing Web-Platform Tests and Gecko mochitests, fixing failures, debugging in a large codebase, and collaborating via public bugs and code review. Required: substantial browser-engine experience (ideally Firefox/Gecko), strong C++ and JavaScript skills, and debugging/testing expertise.

MariaDB seeks a Senior Java Software Engineer to develop, optimize and lead development of a scalable, geo-distributed database solution. Responsibilities include working on replication, sharding, concurrency, performance tuning and high-availability algorithms; mentoring/managing engineers; and collaborating globally. Role requires 4+ years Java experience, deep concurrency and JVM knowledge, SQL/database experience, and familiarity with distributed systems concepts (MVCC, Raft, ACID).

MariaDB seeks a Senior Java Software Engineer to develop, test and lead work on a highly scalable, geo-distributed, high-performance database solution. Responsibilities include ensuring scalability, performance and reliability, debugging and profiling Java applications (JFR, JMC, async-profiler, VisualVM), implementing replication, sharding, consistency and high-availability algorithms, and collaborating across teams. Requires 4+ years Java experience, deep concurrency and JVM knowledge, SQL experience, and leadership ability. Role is remote with allowed locations listed; MariaDB does not sponsor visas or relocation.

Senior QA Automation Engineer (SDET) role on the GridGain Core QA Team responsible for designing, developing and maintaining automated functional and performance tests for a distributed database platform. Requires 5+ years in QA/test automation or software engineering, strong Java skills, experience with distributed/backend systems and familiarity with Docker/Kubernetes, NoSQL and databases (GridGain/Apache Ignite/MariaDB). MariaDB does not sponsor work visas or provide relocation.

Principal Software Engineer role on the globally distributed Elasticsearch Search Infra team based in Poland. The role provides technical vision and direction for core search infrastructure (indexing, retrieval, relevance), requires deep expertise in search internals (Elasticsearch/Lucene/Solr), strong Java skills, and experience with large-scale distributed systems. The position involves cross-team collaboration, mentoring senior engineers, and contributing to the evolution of Elasticsearch's search capabilities.

Responsible for driving customer issue resolution for InfiniBand/NVLink switch deployments, developing features and tools for enterprise networking services, and collaborating with engineering to reproduce and solve issues. Requires a BSc (or equivalent), 10+ years of system software development and troubleshooting experience, C development (kernel/application/embedded), and hands-on experience with datacenter networking protocols such as LACP, OSPF, BGP, EVPN, and VXLAN; familiarity with RDMA/RoCE, DPUs, and HPC (MPI/UCX) is a plus.

Lead the architecture and implementation of LLM‑friendly math library APIs and documentation, collaborate with stakeholders to deliver LLM‑enhanced releases, build metrics and tooling to measure code‑generation impact, and prototype solutions to represent math library APIs for codegen and agent tooling. Preferred background includes MSc/PhD (or equivalent), 3+ years' experience, and familiarity with LLMs, API design, and CUDA‑X libraries.

Work primarily in React Native to build responsive, reliable financial mobile experiences for Kraken's consumer app. Responsibilities include shaping solutions with Product and Design, implementing features end-to-end, working with APIs and real-time data, addressing state management, rendering, performance and architecture, using metrics and experimentation to measure impact, participating in code reviews, and using AI tools to increase productivity. Native Swift or Kotlin experience and fintech/crypto knowledge are desirable.

Role to design and implement Rust services and foundational libraries for Kraken's core infrastructure, emphasizing correctness, security, observability, and long-term maintainability. Requires 7+ years of software engineering experience, experience with distributed systems (RPC, Kafka, event-driven), asynchronous/network service development in Rust, and strong operational ownership and debugging skills.

Lead technical direction for the Duo Agent Platform across multiple teams, design and implement agent orchestration (session lifecycle, tool invocation, concurrency, retries), ensure multi-tenant and self-hosted compatibility, define evaluation frameworks and governance/safety practices, participate in on-call incident management, and mentor senior engineers. Requires 8+ years engineering experience and hands-on production experience with large language models.

Lead technical direction for verification services on Kraken's Pro platform: design and build KYC/KYB flows, abstract vendor integrations, implement fail-closed behavior and audit trails, and eliminate recurring failures. Role expects ~8 years of production experience, deep Rust expertise, familiarity with TypeScript/React, distributed systems, and tools such as gRPC, Temporal, Docker, Kubernetes, Terraform, MySQL/MariaDB, Redis, and GitLab CI.

Remote role based in Poland for GitLab's Pipeline Authoring group. Work includes developing and maintaining backend functionality for CI/CD and the CI/CD Catalog with focus on reliability, performance, scalability, security, and usability. Requires proficiency in Ruby and Ruby on Rails, experience with relational databases (PostgreSQL noted), and collaboration in an asynchronous, cross‑functional environment. Includes participation in Tier 2 on-call rotations.

Join Elastic’s Security EDR Workflows team to implement user-facing workflows and management features for Elastic Defend, build response-actions and OSquery forensics, and develop scalable, high-performance systems. The role involves writing production-grade code (TypeScript/Node.js), collaborating with cross-functional and distributed teams, and using AI to improve development and engineering processes.

Role focuses on enhancing Elasticsearch's vector similarity search (design, implement, and fix features), contributing to Lucene where relevant, working with a globally distributed engineering team, and writing idiomatic modern Java. Requires professional experience with vector similarity/vector databases (experience with HNSW, IVF, or similar), strong core Java skills, familiarity with data storage technologies, and experience collaborating on open source and distributed teams.

Principal Software Engineer role on the Elasticsearch Search team focused on designing and implementing vector similarity search features, improving existing vector search functionality, resolving bugs, and collaborating with a globally distributed engineering and open source community. The role emphasizes Java development, search algorithms (e.g., HNSW, IVF), data structures, concurrency, and performance at scale.

Join the globally distributed Elasticsearch Search Relevance team to design and implement search features, improve vector search (HNSW, IVF and similar algorithms), contribute to Lucene and Elasticsearch codebase, write idiomatic modern Java, collaborate on open source issues and pull requests, and drive technical direction for search relevance.