Senior Software Development Engineer L3 Jobs

Who we are At Twilio, we’re shaping the future of communications, all from the comfort of our homes. We deliver innovative solutions to hundreds of thousands of businesses and empower millions of developers worldwide to craft personalized customer experiences. Our dedication to remote-first work , and strong culture of connection and global inclusion means that no matter your location, you’re part of a vibrant team with diverse experiences making a global impact each day. As we continue to revolutionize how the world interacts, we’re acquiring new skills and experiences that make work feel truly rewarding. Your career at Twilio is in your hands. . Hiring and how we work We use Artificial Intelligence (AI) to help make our hiring process efficient. That said, every hiring decision is made by real Twilions! Also, while we are a remote-first company, you may be asked to report in person on an ad-hoc basis for team gatherings, functional off-sites or customer meetings. . See yourself at Twilio Join the team as Twilio’s next Senior Software Engineer. About the job This position is needed to design, build, and optimize the core signalling infrastructure that powers real-time video communications for our customers. You will play a key role in ensuring high performance, reliability, and scalability of our video platform, enabling seamless and secure video experiences. Responsibilities In this role, you’ll: Design, implement, and maintain video signalling protocols and server components for real-time video calls (e.g., WebRTC, SIP, RTCP/RTP) in a highly scalable distributed system. Collaborate with cross-functional distributed teams and various stakeholders to deliver high-performance, low-latency media experiences. Ensure secure transmission and compliance with industry best practices (e.g., end-to-end encryption, privacy standards). Contribute to architectural decisions and code reviews, mentoring junior engineers as needed. Stay current with

Every day, tens of millions of people come to Roblox to explore, create, play, learn, and connect with friends in 3D immersive digital experiences– all created by our global community of developers and creators. At Roblox, we’re building the tools and platform that empower our community to bring any experience that they can imagine to life. Our vision is to reimagine the way people come together, from anywhere in the world, and on any device. We’re on a mission to connect a billion people with optimism and civility, and looking for amazing talent to help us get there. A career at Roblox means you’ll be working to shape the future of human interaction, solving unique technical challenges at scale, and helping to create safer, more civil shared experiences for everyone. With Roblox’s daily active users growing at a record pace, we are seeking a senior data infrastructure engineer to join our new Data Insights team. Our team owns the data tooling that empowers Roblox builders to independently make informed and timely data-driven decisions. As an engineer on the team, you’ll work on the platforms behind tools like Superset, Hex, and Python notebooks, which provide critical insights into the health of our business to users at every level of the company. We tackle diverse challenges in data engineering, infrastructure, and analytics, to deliver the insights our customers need. You will collaborate closely with engineers across our data ecosystem to shape the future of product analytics at Roblox. This role offers the chance to be a founding team member and help define both the technical direction and the long-term shape of the product area from the ground up. This role is a great fit for you if you are proficient in designing and scale robust data infrastructure and applications and have a zeal for developing inspiring, easily maintainable, and reusable code. Join our team and make a significant impact at Roblox. You Will: Architect and deliver a high-pe

Who we are At Twilio, we’re shaping the future of communications, all from the comfort of our homes. We deliver innovative solutions to hundreds of thousands of businesses and empower millions of developers worldwide to craft personalized customer experiences. Our dedication to remote-first work , and strong culture of connection and global inclusion means that no matter your location, you’re part of a vibrant team with diverse experiences making a global impact each day. As we continue to revolutionize how the world interacts, we’re acquiring new skills and experiences that make work feel truly rewarding. Your career at Twilio is in your hands. . Hiring and how we work We use Artificial Intelligence (AI) to help make our hiring process efficient. That said, every hiring decision is made by real Twilions! Also, while we are a remote-first company, you may be asked to report in person on an ad-hoc basis for team gatherings, functional off-sites or customer meetings. . See yourself at Twilio Join the team as Twilio's next Staff Software Engineer on our Data Substrate team. Who we are & why we’re hiring Twilio powers real-time business communications and data solutions that help companies and developers worldwide build better applications and customer experiences. Although we're headquartered in San Francisco, we have presence throughout South America, Europe, Asia and Australia. We're on a journey to becoming a global company that actively opposes racism and all forms of oppression and bias. At Twilio, we support diversity, equity & inclusion wherever we do business. About the job We are seeking an experienced Staff Engineer to join our Data Substrate team. In this role, you will be responsible for architecting scalable and reliable data solutions, collaborating closely with cross-functional partners driving technical innovation, and mentoring a team of talented engineers. The ideal candidate will have deep expertise in data syste

Who we are At Twilio, we’re shaping the future of communications, all from the comfort of our homes. We deliver innovative solutions to hundreds of thousands of businesses and empower millions of developers worldwide to craft personalized customer experiences. Our dedication to remote-first work , and strong culture of connection and global inclusion means that no matter your location, you’re part of a vibrant team with diverse experiences making a global impact each day. As we continue to revolutionize how the world interacts, we’re acquiring new skills and experiences that make work feel truly rewarding. Your career at Twilio is in your hands. . Hiring and how we work We use Artificial Intelligence (AI) to help make our hiring process efficient. That said, every hiring decision is made by real Twilions! Also, while we are a remote-first company, you may be asked to report in person on an ad-hoc basis for team gatherings, functional off-sites or customer meetings. . See yourself at Twilio Join the team as a Senior Software Engineer for Stytch, where you'll shape the next generation of fraud prevention products. About the job As a Senior Software Engineer you will help develop Stytch’s fraud detection and prevention products as we bring Stytch capabilities to Twilio’s full customer base, delivering secure, developer-first identity and fraud prevention experiences. You’ll primarily work on our Device Fingerprinting product that detects bots, manual abuse, and highly sophisticated reverse engineering to help protect our customers’ from fraud and abuse. You’ll partner closely with product and engineering leadership to evolve our detection techniques to continue to stay ahead of threats. This is a rare chance to operate like a startup within Twilio: you’ll work in a high-ownership environment with startup speed, backed by Twilio’s reach and scale. Responsibilities Build and own fraud detection capabilities for Stytch’s fraud platform

Who we are At Twilio, we’re shaping the future of communications, all from the comfort of our homes. We deliver innovative solutions to hundreds of thousands of businesses and empower millions of developers worldwide to craft personalized customer experiences. Our dedication to remote-first work , and strong culture of connection and global inclusion means that no matter your location, you’re part of a vibrant team with diverse experiences making a global impact each day. As we continue to revolutionize how the world interacts, we’re acquiring new skills and experiences that make work feel truly rewarding. Your career at Twilio is in your hands. . Hiring and how we work We use Artificial Intelligence (AI) to help make our hiring process efficient. That said, every hiring decision is made by real Twilions! Also, while we are a remote-first company, you may be asked to report in person on an ad-hoc basis for team gatherings, functional off-sites or customer meetings. . See yourself at Twilio Join the team as a Senior Software Engineer for Stytch, where you'll shape the next generation of identity products. About the job As a Senior Software Engineer you will help scale Stytch’s core product as we bring Stytch capabilities to Twilio’s full customer base, delivering secure, developer-first identity experiences. You’ll build backend APIs that power authentication, authorization, and emerging agentic and non-human identity use cases. You’ll partner closely with product and engineering leadership to design and deliver high-impact customer-facing features, and evolve our platform for Twilio’s scale. This is a rare chance to operate like a startup within Twilio: you’ll work in a high-ownership environment with startup speed, backed by Twilio’s reach and scale. Responsibilities Build and own backend product capabilities for Stytch’s identity platform on Twilio—shipping new API surfaces and core authentication flows, including agentic and non-huma

Every day, tens of millions of people come to Roblox to explore, create, play, learn, and connect with friends in 3D immersive digital experiences– all created by our global community of developers and creators. At Roblox, we’re building the tools and platform that empower our community to bring any experience that they can imagine to life. Our vision is to reimagine the way people come together, from anywhere in the world, and on any device. We’re on a mission to connect a billion people with optimism and civility, and looking for amazing talent to help us get there. A career at Roblox means you’ll be working to shape the future of human interaction, solving unique technical challenges at scale, and helping to create safer, more civil shared experiences for everyone. As a Senior Software Engineer on the Engine DataModel team, you will own and innovate on the foundational components that form the backbone of the Roblox platform. In the Roblox Engine, the DataModel is a tree-like structure that is analogous to a scenegraph in other 3D engines. This role will report to the engineering manager and will be based out of our HQ in San Mateo, CA in a hybrid model 3 days a week (Tuesdays to Thursdays). Our team owns: The core structures and systems are used to build the DataModel and interact with it. The C++ reflection bindings that form the Engine’s Luau API surface and let creators interact with the DataModel. We’ve built custom codegen tooling to generate the C++ for these reflection bindings and other related structures. DataModel serialization … and much more! You will: Develop engine code that performs well for all user-created games on the Roblox platform. Build the core systems and data structures used in the Roblox engine, working with other teams to find universal solutions. Take ownership of projects throughout their full lifecycles. Execute code that performs well on all the devices Roblox supports—from desktop clients to mobile phone clients to con

Fin is the AI Customer Agent company on a mission to help businesses provide perfect customer experiences. Our AI Agent Fin is the highest-performing AI Customer Agent on the market today, enabling businesses to deliver impeccable, always-on customer support across the customer journey – from service, to sales, to ecommerce. Powered by our own AI models, Fin resolves complex customer issues end-to-end across every channel, with minimal set-up and integration. Fin can also be combined with our natively integrated Intercom help desk for one single system that is designed to meet the needs of modern day support teams. Founded in 2011, Fin became one of the fastest growing companies and remains one of the largest private software companies in the world with nearly 30,000 global businesses using our products to transform their customer support. Driven by our core values, we push boundaries, build with speed and intensity, and relentlessly deliver incredible value to our customers. What's the opportunity? At Fin, you will be a Senior Software Engineer - someone who solves real customer problems through a smart and efficient application of your technical knowledge and your tools. You’ll be part of one of our multidisciplinary product teams, where you will build both back-end and front-end systems, and work closely with designers, product managers, researchers, and data analysts. We’re facing many exciting scaling challenges and we’re building a robust platform where your expertise can be applied to areas such as building a beautiful messenger composer, rule matching, deliverability, security, app availability and machine learning, to name a few. What will I be doing? As an experienced engineer you will: Develop technical plans and contribute to our technical architecture as we scale our products to serve tens of millions of people every day. Write Ruby code, which knits together a lot of AWS, infrastructure, platform and SaaS technologies that form the core of Fin's

The AI Retrieval team powers the intelligence behind Asana's AI features by finding relevant work graph content and delivering it to LLM context windows. Our work enables AI features that truly understand your work—both within and outside of Asana—and use that understanding to take action. We also own Asana's traditional search experience. As a Senior Software Engineer on the AI Retrieval team, you'll build the systems that make Asana's AI smart and responsive. You'll tackle challenging problems in search and retrieval, working to improve the speed, cost-efficiency, and quality of our systems while expanding their capabilities to new data sources. This role is based in our New York City office with an office-centric hybrid schedule. The standard in-office days are Monday, Tuesday, and Thursday. Most Asanas have the option to work from home on Wednesdays. Working from home on Fridays depends on the type of work you do, and your recruiter can share more about the in-office requirements. What you'll achieve Reduce the latency and cost of our retrieval system, making Asana's AI features faster and more efficient Improve the quality and relevance of search results to help users find exactly what they need Expand the retrieval system's capabilities to query new Asana objects and third-party data sources Build and optimize search infrastructure using OpenSearch/ElasticSearch Contribute to ML-powered features like embeddings-based retrieval and semantic search Collaborate with cross-functional partners in New York City while building strong relationships with your Warsaw-based peers About you 6+ years of experience writing code in a production environment Curiosity about how AI and technology can solve problems and a desire to use it regularly in your work Hands-on experience in search engineering, including with OpenSearch or ElasticSearch Experience with embeddings and machine learning approaches to search and retrieval Experience in an Applied AI role is a plus Dem

Asana’s rapid growth brings new challenges in keeping our systems fast, reliable, and resilient. As our product evolves, we’re making a major investment in reliability – and building a brand new SRE team in Warsaw is a key part of that strategy. This is your chance to help shape it from day one. This isn’t a traditional “ops” role – we’re looking for strong software engineers who are passionate about building reliable, distributed systems. You’ll work closely with a small SRE team in San Francisco, infrastructure engineers in Reykjavik, and an established infrastructure team in Warsaw. Warsaw will be a significant hub for our future infrastructure engineering and operations. As one of the first engineers here, you’ll have a real say in how we build reliable infrastructure, manage incidents, and support the rest of the company. This role is based in our Warsaw office with an office-centric hybrid schedule. The standard in-office days are Monday, Tuesday, and Thursday. Most Asanas have the option to work from home on Wednesdays. Working from home on Fridays depends on the type of work you do, and your recruiter can share more about the in-office requirements. We offer a Contract of Employment (UoP) for our employees in Poland. What you’ll achieve Influence the future of Asana’s SRE practice, especially as we grow the Warsaw team. Lead reliability-focused projects across our stack – from infrastructure to tooling to incident response. Define and implement Asana’s incident management process – we’re investing here, and you’ll help shape how it works. Build internal platforms and frameworks that help other teams improve the reliability of their services. Be part of (and help shape) a sustainable on-call rotation – shared across teams in Warsaw, San Francisco, and Reykjavik. On average, we handle ~1 page per day, but it’s not constant, and we care about keeping things sane. Work with our stack: AWS, Kubernetes (EKS), Datadog, MySQL (RDS), ElasticSearch (OpenSearch), Redis

We're looking for a Senior Platform Reliability Engineer who brings strong software engineering skills and a deep understanding of system behavior under load and stress. This role is a good fit for someone who wants to own reliability as a first-class concern – building the foundational systems that protect Asana's platform, not just responding when things go wrong. You'll build core platform systems like load shedding, rate limiting, circuit breakers, and traffic controls that protect Asana under real-world load. This is deep, cross-cutting work that shapes stability and performance of our entire infrastructure – and you'll partner closely with other platform teams to make reliability something that's built in, not bolted on. Our tech stack includes: AWS, Kubernetes (EKS), CloudFront, Istio, Cilium, MySQL (RDS), OpenSearch, DynamoDB, Redis, Terraform, Datadog, TypeScript, Scala, Go, and Python. (Yeah, we know this sounds like buzzword bingo – but we want this post to actually show up in your searches.) Why this role? Reliability as a first-class feature : You won't be patching things up after the fact. You'll build the systems that make Asana resilient by design. Foundational work : Load shedding, traffic management, ingress/egress – these are the building blocks that protect everything else. You'll own them. Strong collaboration, reasonable hours : You'll work closely with infrastructure teams in Warsaw and Reykjavik, making deep collaboration practical without constant timezone gymnastics. Room to grow : This is a new team, and you'll help shape what Platform Reliability Engineering looks like at Asana – whether that means leading projects, mentoring others, or defining our technical direction. In this role, success means shipping systems that other teams rely on by default – because they make the platform safer, not because they're mandatory. We're especially interested in people who think like backend engineers but obsess over failure modes, capacity plan

The AI Retrieval team powers the intelligence behind Asana's AI features by finding relevant work graph content and delivering it to LLM context windows. Our work enables AI features that truly understand your work—both within and outside of Asana—and use that understanding to take action. We also own Asana's traditional search experience. As a Senior Software Engineer on the AI Retrieval team, you'll build the systems that make Asana's AI smart and responsive. You'll tackle challenging problems in search and retrieval, working to improve the speed, cost-efficiency, and quality of our systems while expanding their capabilities to new data sources. This role is based in our Warsaw office with an office-centric hybrid schedule. The standard in-office days are Monday, Tuesday, and Thursday. Most Asanas have the option to work from home on Wednesdays. Working from home on Fridays depends on the type of work you do, and your recruiter can share more about the in-office requirements. We offer a Contract of Employment (UoP) for our employees in Poland. What you'll achieve Reduce the latency and cost of our retrieval system, making Asana's AI features faster and more efficient Improve the quality and relevance of search results to help users find exactly what they need Expand the retrieval system's capabilities to query new Asana objects and third-party data sources Build and optimize search infrastructure using OpenSearch/ElasticSearch Contribute to ML-powered features like embeddings-based retrieval and semantic search Collaborate with cross-functional partners in New York City while building strong relationships with your Warsaw-based peers About you 6+ years of experience writing code in a production environment Demonstrates curiosity about AI tools and emerging technologies, with a willingness to learn and leverage them to enhance productivity, collaboration, or decision-making Hands-on experience in search engineering, including with OpenSearch or ElasticSearch

The Incident Insights & Readiness SRE team at Datadog fosters a resilient culture by using incidents as learning opportunities and catalysts for growth. Our users are Datadog engineers, and we build the software, tooling, and operational frameworks that help them prepare for, respond to, and learn from incidents. We work closely with engineering teams across Datadog to analyze incidents and turn those insights into better tools, stronger incident response, and organizational learning. Our efforts empower Datadog to navigate unexpected failures confidently, efficiently, and with a commitment to continuous learning and systems improvement. At Datadog, we place value in our office culture - the relationships and collaboration it builds and the creativity it brings to the table. We operate as a hybrid workplace to ensure our Datadogs can create a work-life harmony that best fits them. The Incident Insights & Readiness SRE team at Datadog fosters a resilient culture by using incidents as learning opportunities and catalysts for growth. Our users are Datadog engineers, and we build the software, tooling, and operational frameworks that help them prepare for, respond to, and learn from incidents. We work closely with engineering teams across Datadog to analyze incidents and turn those insights into better tools, stronger incident response, and organizational learning. Our efforts empower Datadog to navigate unexpected failures confidently, efficiently, and with a commitment to continuous learning and systems improvement. At Datadog, we place value in our office culture - the relationships and collaboration it builds and the creativity it brings to the table. We operate as a hybrid workplace to ensure our Datadogs can create a work-life harmony that best fits them. What You’ll Do: Own and improve the on-call experience for the company by establishing best practices and building platforms to support on-call rotations and compensation

The eBPF APM team is building a zero-instrumentation observability solution that automatically discovers services on every host, supports both plaintext and TLS-encrypted traffic, classifies Layer 7 protocols, decodes service-level traffic, and reports RED (requests, errors, duration) metrics. Leveraging deep expertise in eBPF, the team operates across a wide range of Linux kernel versions, distributions, and complex customer environments. In addition to low-level networking, the team solves challenges related to protocol versioning, TLS detection across diverse languages and runtimes, and resilient performance in production systems We’re looking for a senior engineer with strong systems-level thinking and a good understanding of Linux. You should be comfortable working close to the kernel, ideally with experience in eBPF, or with a strong desire to dive into it. Proficiency in C/C++/ Go is essential, and familiarity with networking protocols, TLS internals, or distributed tracing is a strong advantage. You’ll join a high-impact team tackling ambitious technical challenges—like decoding traffic across multiple protocols, and ensuring high-fidelity metrics in complex, real-world environments. You’ll be expected to lead design and implementation efforts, contribute to roadmap planning, and collaborate across teams to ensure our solution remains robust, scalable, and frictionless for our users. This role is a great fit for engineers who thrive on low-level, performance-sensitive problems, and want to shape the future of observability through cutting-edge kernel technology. At Datadog, we place value in our office culture - the relationships that it builds, the creativity it brings to the table, and the collaboration of being together. We operate as a hybrid workplace to ensure our employees can create a work-life harmony that best fits them. What You’ll Do: Design and build core components of our zero-instrumentation APM product using eBPF and Go Develop systems to aut

Senior Software Engineer - Streaming Platform Client Data streams are mission-critical at Datadog, powering near real-time communication across the vast majority of our services. Our Streaming Platform group builds the core infrastructure and abstractions that ensure Datadog remains a trusted partner for engineers worldwide. See our blog post . The Streaming Platform Client team sits at the heart of this ecosystem. We own the Rust client library (producers and consumers) with language bindings for Java, Go, and Python. We focus on building intuitive APIs and abstractions that make a powerful distributed system easy to adopt and operate for the hundreds of internal users of our library. Our library runs on critical data paths that handle hundreds of millions of messages per second making performance, observability, and reliability paramount. We also develop and operate the service that bridges the clients fleet with the platform's control plane, handling complex balancing, scaling, and static stability challenges. We are seeking a Senior Software Engineer to help us evolve these features. You will collaborate directly with our users, tackle performance-critical code, and solve complex distributed systems challenges across the control plane, client libraries, and data plane. At Datadog, we place value in our office culture - the relationships and collaboration it builds and the creativity it brings to the table. We operate as a hybrid workplace to ensure our Datadogs can create a work-life harmony that best fits them. What You’ll Do: Work within a distributed, high-impact team spanning Europe and the US, building critical technologies that power data pipelines for dozens of internal teams and hundreds of services. Architect and implement resilient interactions between our client libraries and the control plane. Optimize our high-throughput, low-level streaming library to push the boundaries of performance and efficiency. Champion the developer experience by providing

About Datadog: We're on a mission to build the best platform in the world for engineers to understand and scale their systems, applications, and teams. We operate at high scale—trillions of data points per day—providing always-on alerting, metrics visualization, logs, and application tracing for tens of thousands of companies. Our engineering culture values pragmatism, honesty, and simplicity to solve hard problems the right way. You will: Solve a scaling bottleneck in a critical service Deploy a new feature to production, progressively rolling it out with feature flags Investigate and fix a production issue from a service your team owns Design a way to scale up a service for more traffic With your team, plan the most important projects to work on next Who You Are: You have significant experience in one or more languages You value code simplicity and performance You can design architecture to solve problems at high scale You have a BS/MS/PhD in a scientific field or equivalent experience You want to work in a fast, high-growth startup environment that respects its engineers and customers You have demonstrated ability to use AI coding tools in day-to-day workflows and build, validate, and refine AI-generated output in products You can design AI Backend systems, with awareness of quality, cost, and latency tradeoffs 6+ years of experience Bonus points: You've worked at high scale with systems like Redis, Cassandra, Kafka You wrote your own data pipelines once or twice before You have a strong background in statistics You have significant experience with Go, C, or Python You’re excited about leveraging AI tools to enhance how you code, solve problems, and build – or eager to learn how You’re motivated to push the boundaries of how AI can improve software engineering best practices and contribute to building AI-enabled products Datadog values people from all walks of life. We understand not everyone will meet all the above qualificat