Work on designing, implementing, testing, and shipping security and hardening features for Firefox, improving security architecture (including cryptographic protocols and WebPKI), investigating and fixing security issues, and diagnosing stability, correctness, performance, and memory problems in a large, multithreaded, cross-platform codebase. Requires 3+ years of low-level systems programming experience, strong C/C++ proficiency, security knowledge, and familiarity with web technologies and Rust.

Work on DuckDuckGo's C++ Functional Team to design and implement high-performance browser features using modern C++ and Chromium. Lead complex end-to-end projects, focus on performance, concurrency, memory management, and metrics. Remote role across many countries; requires ~40 hours/week and occasional travel for all-hands and team retreats.

Remote (contract) Senior Software Engineer, Android to support App Experience and App Growth within Core Experiences. Responsibilities include delivering medium-complexity initiatives, system design, improving Android app experiences, ensuring quality/testing/observability, and cross-functional collaboration. Role requires at least four hours overlap between 15:00–21:00 UTC. Requires a bachelor's and 5+ years related experience; strong Kotlin, Jetpack Compose, XML and Android performance optimisation experience. Hiring is available in a specified list of countries (also multiple US states). A US compensation range is listed in the posting.

Join Elastic's Streams UI team to design and implement UI components and integrate front-end code with back-end services for Fleet and Streams (log ingestion/observability). Responsibilities include end-to-end ownership of complex problems, architecture and system design, coding standards, automated testing and deployment, code reviews, usability testing, and async collaboration across a distributed team. Compensation range provided: €67,000–€106,000 EUR (base salary).

Join Kraken’s Consumer Mobile team to design and ship production React Native features for a new app targeting Asian users. Responsibilities include end-to-end feature ownership, working with APIs and real-time data, collaborating closely with Product and Design, raising engineering standards through technical discussions and code reviews, and addressing regional UX, firewall, and connectivity challenges. English communication is required; experience in fintech/crypto and native mobile (Swift/Kotlin) is a plus.

Ownership of CI/CD roadmap and technical vision; design and enforce release gates for supply chain integrity; direct and mentor engineers on multi-quarter cross-org projects; serve as Incident Commander for high-severity supply chain or release incidents; remain hands-on with tooling such as Buildkite, GitHub Actions, GitOps/ArgoCD, and Kubernetes.

Role involves developing and implementing architectural and code-level performance improvements for Elasticsearch, building performance models and benchmarks, profiling and analyzing system behavior (logging, metrics, vector search, ES|QL), ensuring regression detection for stateful and serverless deployments, and contributing automation including AI-assisted optimization harnesses. Requires deep Java/JVM knowledge, concurrency and multithreaded programming, experience with benchmarking tools (e.g., JMH, Rally), and familiarity with distributed systems and large-scale data store internals.

Join the Elasticsearch inference team to maintain and develop the Inference API and plugin framework that integrates Elasticsearch with internal and external ML providers. Responsibilities include building provider integrations, protocol and API work (streaming/SSE), rate limiting, billing integration, writing tests (ESTestCase, YAML REST integration, rolling-upgrade), reviewing contributions, and participating in on-call rotations. Requires 5+ years production Java experience and familiarity with concurrency, API design, and Java build tools.

Join the Streams Backend team to design, build and operate core backend services and Logstash features. Work includes developing in Java, Golang and JRuby, contributing to the OpenTelemetry Collector, solving distributed systems problems at scale, maintaining code and tests, participating in on-call rotations, and engaging with public GitHub repositories and community forums.

Work on the Web Dependability Engineering team to identify why sites break with DuckDuckGo browsers, distinguish site/browser/privacy-caused issues, lead incident response for major site breakages, build durable cross-platform fixes and automation (including LLM agent pipelines), and reverse-engineer third-party code to produce minimal repro cases.

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.

Lead engineering role owning end-to-end improvement of agent behaviour, telemetry, evaluation and safe rollout of prompts/skills/automations for the Context Engine. Requires 10+ years of software engineering experience shipping AI-driven products in production, strong backend skills in TypeScript or Python, experience with agents, telemetry, evaluation, and familiarity with Elasticsearch and MCP.

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.

Join the Elasticsearch Search Infra team as a Principal Software Engineer to define and implement core search and indexing capabilities, drive technical vision, and collaborate across teams. The role requires deep expertise in search internals (Elasticsearch/Lucene/Solr), strong Java and data-structure skills, experience with large-scale distributed systems, and leadership/mentoring experience.

Sysdig is hiring a Technical Engineering Lead to manage and scale the team that builds the runtime agent. The role involves setting technical direction, reviewing designs and code, unblocking engineers, and collaborating with product and security teams to deliver features without regressing performance or stability. Required experience includes leading engineering teams, developing and operating low-level systems software (C/C++), deep knowledge of Linux internals and instrumentation (eBPF or kernel modules), and working with containerized/orchestrated systems (Kubernetes, containerd, cgroup).

Join the Prism team to design and ship scalable, correct, and performant systems that turn security data into a trustworthy picture of users, hosts, and services. Responsibilities include data modeling, background tasks, APIs, performance optimization, telemetry and tests. Required: several years building production software and strong TypeScript/JavaScript skills (React, Node.js). Familiarity with Kibana, Elasticsearch, SIEM/UEBA, and performance profiling are listed as bonuses.