Kotlin Jobs

At Affirm, we exist for the moments that matter—giving people a clear, predictable way to pay over time, with no hidden fees, no surprises, and no tradeoffs on what matters most. The Fraud Engineering organization builds the foundational and tactical software that enables Affirm to respond strategically to fraud - both in real time and after the transaction. Our mission is to support business growth while protecting Affirm, our buyers, and our merchants. We evaluate risk at critical decision points in the user journey, rapidly adapt to evolving fraud patterns, and equip operations teams with the tools needed to investigate and mitigate fraud at scale. We’re looking for a Senior Software Engineer to join our fully remote team based in Europe. You’ll collaborate closely with stakeholders across North America - including teams in Product, Compliance, Machine Learning, Fraud Operations, Fraud Strategy, and other Fraud Engineering teams. The Fraud Engineering organization builds the foundational and tactical software that enables Affirm to respond strategically to fraud - both in real time and after the transaction. Our mission is to support business growth while protecting Affirm, our customers, and our merchants. We evaluate risk at critical decision points in the user journey, rapidly adapt to evolving fraud patterns, and equip operations teams with the tools needed to investigate and mitigate fraud at scale. The Fraud International Team (FIT) leads the engineering effort to extend Affirm's Fraud Decisioning System into markets beyond the US - Canada, the UK, Australia, and growing rapidly. We own real-time fraud decisioning for these markets, integrate region-specific risk vendors, and are building the platform that lets Affirm stand up fraud protection in a new country quickly and safely. As Affirm expands globally, FIT scales with it. We're looking for a Senior Software Engineer to join our fully remote team based in Europe. You'll collaborate closely w

At Affirm, we exist for the moments that matter—giving people a clear, predictable way to pay over time, with no hidden fees, no surprises, and no tradeoffs on what matters most. The Fraud Engineering organization builds the foundational and tactical software that enables Affirm to respond strategically to fraud - both in real time and after the transaction. Our mission is to support business growth while protecting Affirm, our buyers, and our merchants. We evaluate risk at critical decision points in the user journey, rapidly adapt to evolving fraud patterns, and equip operations teams with the tools needed to investigate and mitigate fraud at scale. We’re looking for a Senior Software Engineer to join our fully remote team based in Europe. You’ll collaborate closely with stakeholders across North America - including teams in Product, Compliance, Machine Learning, Fraud Operations, Fraud Strategy, and other Fraud Engineering teams. The Fraud Engineering organization builds the foundational and tactical software that enables Affirm to respond strategically to fraud - both in real time and after the transaction. Our mission is to support business growth while protecting Affirm, our customers, and our merchants. We evaluate risk at critical decision points in the user journey, rapidly adapt to evolving fraud patterns, and equip operations teams with the tools needed to investigate and mitigate fraud at scale. The Fraud International Team (FIT) leads the engineering effort to extend Affirm's Fraud Decisioning System into markets beyond the US - Canada, the UK, Australia, and growing rapidly. We own real-time fraud decisioning for these markets, integrate region-specific risk vendors, and are building the platform that lets Affirm stand up fraud protection in a new country quickly and safely. As Affirm expands globally, FIT scales with it. We're looking for a Senior Software Engineer to join our fully remote team based in Europe. You'll collaborate closely w

Airbnb was born in 2007 when two hosts welcomed three guests to their San Francisco home, and has since grown to over 5 million hosts who have welcomed over 2 billion guest arrivals in almost every country across the globe. Every day, hosts offer unique stays and experiences that make it possible for guests to connect with communities in a more authentic way. The Community You Will Join The Quality Platform team is at the heart of Airbnb’s mission to deliver a seamless, high-quality experience for millions of hosts and guests. We don’t just find bugs — we build the systems that prevent them. Our team sits at the intersection of Quality Engineering, Infrastructure, and Applied AI. We are evolving how software quality is built by integrating LLMs, intelligent automation, and data-driven systems into the testing lifecycle. You will join a high-impact group of engineers focused on building AI-powered quality systems that scale across one of the world’s most complex codebases. The Difference You Will Make: As a Mobile Software Engineer, you will be a key contributor to the development of our Quality Platform across both native mobile stacks. You will help build the foundation for how quality is engineered across Airbnb's iOS and Android ecosystems, developing tools and frameworks that enable our mobile platform to scale while keeping developers productive and confident, regardless of which platform they build on. In this role, you will: Build AI-Driven Solutions: Contribute to AI-native agents that automate repetitive testing tasks and provide intelligent feedback to developers on both platforms.Deliver Scalable Infrastructure: Develop and maintain the high-scale platforms and testing environments used daily by the iOS and Android engineering organizations.Promote Engineering Craft: Implement best-in-class mobile patterns and modularity to improve testability and fault-tolerance across both native codebases.Contribute to Operational Excellence: Ensure our automated syste

At Lyft, our purpose is to serve and connect. We aim to achieve this by cultivating a work environment where all team members belong and have the opportunity to thrive. Lyft Urban Solutions powers the bike-sharing and scooter-sharing systems that move millions of people in over 60 cities worldwide. We built North America's first automated bike-share system and continue to lead the micromobility revolution. Our systems operate globally - from Citi Bike in New York to BIXI in Montreal, Divvy in Chicago, Capital Bikeshare in DC, and iconic systems in Austin, Barcelona, Bogota, Boston, Buenos Aires, Columbus, Detroit, Dubai, London, Madrid, Mexico City, Monaco, Pittsburgh, Portland, Rio de Janeiro, San Francisco, Toronto, and beyond. We're not just technology providers - we operate these systems, building the software, hardware, and operations that make urban micromobility work at scale. Ready to shape how millions of people move through their cities every day? We're looking for an Android Software Engineer to join the Rider Experience team within Lyft Urban Solutions. Your work will directly power the digital experiences behind our bike-share and scooter-share platforms. You'll build the backend systems that make membership programs, rider features, and real-time experiences feel seamless and fast. We're moving quickly on this hire; the team has ambitious goals for 2026 and needs strong engineers who are ready to ship. Our engineers are sharp, pragmatic problem-solvers who move fast and deploy to production continuously. Responsibilities: Engineering & Delivery Design, develop, deploy, monitor, operate, and maintain elements of our Rider experience, owning components end to end Write reliable, performant, and maintainable code, with comprehensive test coverage Reduce technical debt and contribute to ongoing improvements in tooling and code structure Analyze internal systems and processes to identify opportunities for improvement and automation Participate in code r

Who are we? Cohere is the leading security-first enterprise AI company. We build cutting-edge foundation AI models and end-to-end products that are designed to solve real-world business problems. We’re training and deploying frontier models for enterprises who are building AI systems. We believe that our work is instrumental to the widespread adoption of AI and we are looking for folks that want to be part of that. We obsess over what we build. Each one of us is responsible for contributing to increasing the capabilities of our models and the value they drive for our customers. Cohere is a team of researchers, engineers, designers, and more, who are all passionate about their craft. We are a global technology company headquartered in Toronto with key offices in London, New York City, San Francisco, Montreal, Paris, Berlin and Seoul. Join us! Why this role? North is Cohere's cutting-edge AI workspace platform, designed to transform how enterprises leverage AI. It provides a secure, customizable environment that enables organizations to deploy AI solutions while maintaining strict control over sensitive data. The North app is deployed directly to customers in highly regulated industries, delivering a seamless experience that empowers teams to work efficiently and securely at their best. We're seeking iOS and Android experts to join our close-knit team, where you'll drive exceptional impact on mission-critical projects. As a Senior Mobile Engineer, you will: Build and ship features for North, our AI workspace platform Collaborate with UI/UX designers to implement interface elements As security and privacy are paramount, you will sometimes need to re-invent the wheel, and won’t be able to use the most popular libraries or tooling Collaborate with researchers to productionize state-of-the-art models and techniques Research new technologies and best practices You may be a good fit if you: Have shipped (lots of) Android and iOS code (Kotlin, Swift) in production Built nati

GitLab is the intelligent orchestration platform for DevSecOps. GitLab enables organizations to increase developer productivity, improve operational efficiency, reduce security and compliance risk, and accelerate digital transformation. More than 50 million registered users and more than 50% of the Fortune 100* trust GitLab to ship better, more secure software faster. The same principles built into our products are reflected in how our team works: we embrace AI as a core productivity multiplier, with all team members expected to incorporate AI into their daily workflows to drive efficiency, innovation, and impact. GitLab is where careers accelerate, innovation flourishes, and every voice is valued. Our high-performance culture is driven by our values and continuous knowledge exchange, enabling our team members to reach their full potential while collaborating with industry leaders to solve complex problems. Co-create the future with us as we build technology that transforms how the world develops software. * Fortune 500® is a registered trademark of Fortune Media IP Limited, used under license. Claim based on GitLab data. Fortune 100 refers to the top 20% ranked companies in the 2025 Fortune 500 list, published in June 2025. Fortune and Fortune Media IP Limited are not affiliated with, and do not endorse products or services of GitLab. An overview of this role As a Senior Software Engineer on the Duo CLI functional team, part of the Developer Clients group within GitLab's AI Clients stage, you'll design and build tools that bring GitLab Duo into developers' daily terminal workflows. You'll shape AI-assisted experiences across GitLab Duo CLI and its supporting infrastructure, working mainly in TypeScript across the frontend and backend and making key architectural decisions about the CLI's future direction. You'll also have opportunities to contribute across Developer Clients, including our JetBrains plugin in Kotlin and our VS Code extension in TypeScript, when

Airbnb was born in 2007 when two hosts welcomed three guests to their San Francisco home, and has since grown to over 5 million hosts who have welcomed over 2 billion guest arrivals in almost every country across the globe. Every day, hosts offer unique stays and experiences that make it possible for guests to connect with communities in a more authentic way. The Community You Will Join: Airbnb is a mission-driven company dedicated to helping create a world where anyone can belong anywhere. It takes a unified team committed to our core values to achieve this goal. Airbnb's various functions embody the company's innovative spirit and our fast-moving team is committed to leading as a 21st century company. The Difference You Will Make: The Service Tools team's mission is to enable Airbnb backend developers to develop, test, and maintain their code quickly and reliably. We own the standard development lifecycle for service owners — from AI-assisted development, through the build system, integration testing and code review, to how services get built for deployment. This represents Airbnb's largest cohort of developers, and you will ultimately be responsible for their productivity. As a Staff Engineer, you will set technical direction rather than only deliver against it. You will own a platform-spanning area of the developer lifecycle end to end — framing the problem, building the measurement that proves it matters, driving a roadmap with partner teams across the company, and growing the engineers who build it with you. The next 18–24 months of this platform are genuinely open: agentic development is changing what the inner loop looks like, and we want someone who wants to help decide what it should become. A Typical Day: Owning a multi-quarter, platform-spanning workstream — agentic developer workflows, intelligent build infrastructure, test excellence, codebase modernization, or developer observability — as the DRI other teams come to Advancing our AI-assisted developme

We're transforming the grocery industry At Instacart, we invite the world to share love through food because we believe everyone should have access to the food they love and more time to enjoy it together. Where others see a simple need for grocery delivery, we see exciting complexity and endless opportunity to serve the varied needs of our community. We work to deliver an essential service that customers rely on to get their groceries and household goods, while also offering safe and flexible earnings opportunities to Instacart Personal Shoppers. Instacart has become a lifeline for millions of people, and we’re building the team to help push our shopping cart forward. If you’re ready to do the best work of your life, come join our table. Instacart is a Flex First team There’s no one-size fits all approach to how we do our best work. Our employees have the flexibility to choose where they do their best work—whether it’s from home, an office, or your favorite coffee shop—while staying connected and building community through regular in-person events. Learn more about our flexible approach to where we work. Overview The Digital Twin Platform team at Instacart is on a mission to understand exactly what is on store shelves at any given moment. Inventory intelligence is foundational to some of Instacart's most critical products — from search and logistics to enterprise AI solutions for grocers of all sizes. Our team owns the end-to-end data supply chain, spanning ingestion and integration of partner data sources, collection of in-store inventory observations, model development, serving, and product integrations across the Instacart ecosystem. We're a growing team sitting at the intersection of physical retail and cutting-edge technology, working closely with Caper, Inventory Intelligence, and Fulfillment to bring real-time shelf intelligence to life. If you're curious about what that looks like in practice, you can read more about our work here: Instacart Enterprise AI S

We're transforming the grocery industry At Instacart, we invite the world to share love through food because we believe everyone should have access to the food they love and more time to enjoy it together. Where others see a simple need for grocery delivery, we see exciting complexity and endless opportunity to serve the varied needs of our community. We work to deliver an essential service that customers rely on to get their groceries and household goods, while also offering safe and flexible earnings opportunities to Instacart Personal Shoppers. Instacart has become a lifeline for millions of people, and we’re building the team to help push our shopping cart forward. If you’re ready to do the best work of your life, come join our table. Instacart is a Flex First team There’s no one-size fits all approach to how we do our best work. Our employees have the flexibility to choose where they do their best work—whether it’s from home, an office, or your favorite coffee shop—while staying connected and building community through regular in-person events. Learn more about our flexible approach to where we work. Overview The Digital Twin Platform team at Instacart is on a mission to understand exactly what is on store shelves at any given moment. Inventory intelligence is foundational to some of Instacart's most critical products — from search and logistics to enterprise AI solutions for grocers of all sizes. Our team owns the end-to-end data supply chain, spanning ingestion and integration of partner data sources, collection of in-store inventory observations, model development, serving, and product integrations across the Instacart ecosystem. We're a growing team sitting at the intersection of physical retail and cutting-edge technology, working closely with Caper, Inventory Intelligence, and Fulfillment to bring real-time shelf intelligence to life. If you're curious about what that looks like in practice, you can read more about our work here: Instacart Enterprise AI S

At Lyft, our mission is to improve people’s lives with the world’s best transportation. To do this, we start with our own community by creating an open, inclusive, and diverse organization. As a Staff Android Engineer, on the Rider App group in the Rider org, you will work on one of Lyft’s most critical Rider flows. The Rider App group is responsible not only for the critical flows in the app but also the app platform and quality. We build and iterate on rider facing products that not only ensure a seamless experience for our riders, but also aim to build and deepen Rider-Lyft relationships. As an experienced app developer you will be solving complex problems, delivering significant impact and ensuring excellence for the Rider Android team. This means excellent development practices, scalable and reliable code architecture, and safe, rapid releases. You will not only influence the architecture, platform, processes but also influence the culture and coach, guide engineers across the group. Responsibilities: Work across our product teams to design, build, and release exciting features and products in the Lyft Rider application, used by millions of people every day Define long term roadmap and architecture based on technology and our needs Oversee major changes to our Android architecture Work with Product Managers, Designers, and other Engineers to deliver best in class user experience and collaborate closely with local and global colleagues Continuously discover, evaluate and implement new technologies to maximize developer efficiency Mentor and support other developers on your team with code reviews, design feedback, and advice and guidance Solve complex real-time data transfer and synchronization issues Implement pixel perfect designs with advanced interactions, which are a joy to use Experience: 6+ years of experience as an Android developer Experience with leading a technical team is a bonus Advanced knowledge of Java and Kotlin Familiarity with RxJav

Airbnb was born in 2007 when two hosts welcomed three guests to their San Francisco home, and has since grown to over 5 million hosts who have welcomed over 2 billion guest arrivals in almost every country across the globe. Every day, hosts offer unique stays and experiences that make it possible for guests to connect with communities in a more authentic way. The Community You Will Join: Everyone at Airbnb thinks about trust, but our team obsesses over it daily. At the core of trust is safety, and thus we spend a significant amount of our time and energy keeping the community safe. The Trust team is responsible for developing the technology that helps protect our community and platform from fraud while also ensuring our hosts, guests, homes, and experiences meet our high standards. We constantly work to fight against online fraud (such as monetary loss, compromised accounts, spam and scam in messages, fake inventory, etc.) as well as offline fraud (theft, property damage, personal safety, etc.). We also work on onboarding and screening of users, and think about complex topics like identity and reputation to ensure that every interaction with Airbnb helps build trust in us and our community. Trust Engineering is responsible for the technology vision and development of a complex stack that runs on every key interaction on the platform. The Difference You Will Make: As a senior technical individual contributor, you will partner closely with our leaders across the broader technical organization helping design, execute and deliver in a complex and collaborative roadmap of Trust engineering efforts that will require collaboration across many parts of the organization and many parts of Airbnb. Although you will be at one of our highest levels of seniority, all individual contributors at Airbnb are Software Engineers which means we expect you to be hands on and contribute code. A Typical day: Define and execute the long-term vision and strategy for the Trust Platform, drivi

Airbnb was born in 2007 when two hosts welcomed three guests to their San Francisco home, and has since grown to over 5 million hosts who have welcomed over 2 billion guest arrivals in almost every country across the globe. Every day, hosts offer unique stays and experiences that make it possible for guests to connect with communities in a more authentic way. Location This position needs to be based in the Beijing, China office 3 days a week. No Relocation and Visa Support The Community You Will Join The Notifications team at Airbnb is dedicated to designing and building the core notification systems that deliver seamless and effective notification experiences to our guests and hosts globally. We collaborate with product teams across the company to understand notification needs and empower them through scalable solutions. By leveraging modern technology and thoughtful governance, we strive to enhance guest and host engagement, minimize user fatigue, and drive meaningful business outcomes. The Difference You Will Make We are looking for backend engineers who are passionate about building reliable systems and delivering user impact through their work. You will work in a global collaboration environment to turn product and engineering ideas into production systems. You will contribute to the development and evolution of our notification platform, help improve delivery timing and channel selection, and build scalable solutions that support

About Stripe Stripe is a financial infrastructure platform for businesses. Millions of companies—from the world’s largest enterprises to the most ambitious startups—use Stripe to accept payments, grow their revenue, and accelerate new business opportunities. Our mission is to increase the GDP of the internet, and we have a staggering amount of work ahead. That means you have an unprecedented opportunity to put the global economy within everyone’s reach while doing the most important work of your career. About the team Stripe Terminal helps Stripe users extend their online presence into the physical world. The Terminal team’s mission is to make it as easy for businesses to accept in-person payments as the Stripe API has done for online payments. With Terminal, businesses can unlock in-person payments use cases that are right for their business model—whether it’s creating a flagship retail experience, extending their website to a pop-up store, or enabling a mobile point-of-sale at their next event. What we are looking for: As an Android BSP Engineer, you will be responsible for the kernel and driver level system development, which includes building, troubleshooting, and writing automated tests for the Android system on our embedded payments platforms. This team works closely with partner teams throughout the hardware and software product lifecycle, from hardware manufacturing to Android app teams. We also work with external vendors on part selection and initial hardware bring-up. What you’ll do: Bring up new devices and lead debugging and performance tuning exercises that span multiple hardware/firmware/software teams. Design, implement, and maintain drivers and Android services that operate efficiently in a constrained environment and meet the reliability and security requirements of the industry. Own the definition of one or more work streams focused on hardware bring-up, peripheral drivers and communication, and power and performance management and opti

Software Developer in Test Description - This role is responsible for ensuring quality, reliability and performance of software applications throughout the development lifecycle primary through software test automation. The role designs, codes, and implements software test automation using appropriate programming languages, frameworks, and tools. The role works closely with cross-functional teams to gather requirements, provide technical insights, and ensure the successful execution of test automation with the main goal of improve quality of the solution. The role also creates and executes comprehensive test plans, test cases, and test scripts based on project specifications. The role sets and provides design guidance to other developers and SQA engineers regarding test automation and the test framework. *Onsite in Ft Collins 4-days a week Responsibilities • Designs quality assurance and test processes for portions of end-user video conferencing/collaboration application, systems software running on android hardware, local, networked, and Internet-based platforms. • Analyzes design and determines test scripts, coding, automation, and integration activities required based on specific objectives and established project guidelines. • Designs and maintains Test automation framework • Executes and writes portions of testing plans, protocols, and documentation for assigned portion of application; identifies and debugs issues with code and suggests changes or improvements. • Identifies opportunities for performance improvements and optimizes code and application performance. • Utilizes latest AI tools and technologies in speeding up test automation • Executes test cases depending on the needs of the project • Provides valuable input into the development of user stories and acceptance criteria, shaping a quality-oriented d

About the Team DoorDash is building the world’s most reliable on-demand logistics engine for delivery! We’re looking for machine learning engineer interns to join our fast-growing engineering team to help us develop a 24x7 global infrastructure system that powers DoorDash’s three-sided marketplace of consumers, merchants, and dashers. About the Role As a Machine Learning Engineer intern at Doordash, you’ll work on tackling new challenges in machine learning and artificial intelligence. You’ll conduct research that can be applied across Doordash engineering teams and engage in external collaborations and mentoring, while also performing research in any of the following areas: Auction, Game theory, Recommender systems, Ranking, AdTech, Computer Vision, Causal Inference, and Big data analytics. We offer a 12-week summer internship program in our San Francisco, Sunnyvale, New York, or Seattle offices. You’re excited about this opportunity because you will… Use cutting-edge research in ML/AI, NLP, RecSys, Ranking, Computer Vision, Causal Inference, Ad Tech, Graph analysis to solve real-world problems across discovery, ads,forecasting, fulfillment and search experiences at Doordash. Contribute and execute on research ideas that can be applied and used to improve product experience at Doordash. Collect, analyze, and synthesize findings from data and use these insights to build relevant ML models. Write clean, efficient, and sustainable code We’re excited about you because you… Are working towards a Masters degree in Computer Science, ML, NLP, Statistics, Information Sciences or related field and are graduating between Fall 2027 & Summer 2028 Have a mastery of at least one systems languages (Java, C++, Python, Kotlin, GoLang) or one ML framework (Tensorflow, Pytorch, MLFlow) Have experience in research and in solving analytical problems Are a strong communicator and team player. Have a passion for applied ML and the Doordash product Ideally have