Senior Platform Engineer Jobs

Synthesia is the world’s leading AI video platform for business, used by over 90% of the Fortune 100. Founded in 2017, the company is headquartered in London, with offices and teams across Europe and the US. As AI continues to shape the way we live and work, Synthesia develops products to enhance visual communication and enterprise skill development, helping people work better and stay at the center of successful organizations. Following our recent Series E funding round, where we raised $200 million, our valuation stands at $4 billion. Our total funding exceeds $530 million from premier investors including Accel, NVentures (Nvidia's VC arm), Kleiner Perkins, GV, and Evantic Capital, alongside the founders and operators of Stripe, Datadog, Miro, and Webflow. About the role As an Applied Research Engineer in our Video team, you will help build the next generation of production-grade foundation models for human-centric video generation. You will join a highly focused team working at the intersection of large-scale generative modeling, distributed systems, and production engineering. Our mission is to develop and optimize video base models that power realistic, controllable, and emotionally expressive synthetic humans at scale. This is not pure research. This is applied research with direct product impact. You will work on advancing training recipes, scaling distributed systems, improving evaluation frameworks, and optimizing inference to ensure our models are high quality, stable, and efficient enough for real-world deployment. Your work will directly influence models used by tens of thousands of businesses worldwide. What you’ll do You will own and execute end-to-end research and engineering projects, from hypothesis to production impact. This includes: Developing and scaling latent video diffusion models tailored for human-centric video generation Designing conditioning mechanisms to improve control (pose, emotion, script, camera) without sacrificing fidelity Advanc

Synthesia is the world’s leading AI video platform for business, used by over 90% of the Fortune 100. Founded in 2017, the company is headquartered in London, with offices and teams across Europe and the US. As AI continues to shape the way we live and work, Synthesia develops products to enhance visual communication and enterprise skill development, helping people work better and stay at the center of successful organizations. Following our recent Series E funding round, where we raised $200 million, our valuation stands at $4 billion. Our total funding exceeds $530 million from premier investors including Accel, NVentures (Nvidia's VC arm), Kleiner Perkins, GV, and Evantic Capital, alongside the founders and operators of Stripe, Datadog, Miro, and Webflow. About the role As a Research Engineer in our Video team, you will help build the next generation of production-grade foundation models for human-centric video generation. You will join a highly focused team working at the intersection of large-scale generative modeling, distributed systems, and production engineering. Our mission is to develop and optimize video base models that power realistic, controllable, and emotionally expressive synthetic humans at scale. This is not pure research. This is applied research with direct product impact. You will work on advancing training recipes, scaling distributed systems, improving evaluation frameworks, and optimizing inference to ensure our models are high quality, stable, and efficient enough for real-world deployment. Your work will directly influence models used by tens of thousands of businesses worldwide. What you’ll do You will own and execute end-to-end research and engineering projects, from hypothesis to production impact. This includes: Developing and scaling latent video diffusion models tailored for human-centric video generation Designing conditioning mechanisms to improve control (pose, emotion, script, camera) without sacrificing fidelity Advancing distr

Synthesia is the world’s leading AI video platform for business, used by over 90% of the Fortune 100. Founded in 2017, the company is headquartered in London, with offices and teams across Europe and the US. As AI continues to shape the way we live and work, Synthesia develops products to enhance visual communication and enterprise skill development, helping people work better and stay at the center of successful organizations. Following our recent Series E funding round, where we raised $200 million, our valuation stands at $4 billion. Our total funding exceeds $530 million from premier investors including Accel, NVentures (Nvidia's VC arm), Kleiner Perkins, GV, and Evantic Capital, alongside the founders and operators of Stripe, Datadog, Miro, and Webflow. About the role Lead the delivery of complex engineering projects focused on driving user acquisition, activation, and revenue growth. Break down initiatives into manageable stages with predictable timelines, making clear trade-offs between speed, experimentation, and long-term scalability. Partner closely with product and data to prioritize high-impact work and maximize business outcomes. Understand engineering levelling and scale the team by identifying and filling skill gaps, particularly in areas like experimentation, performance, and conversion optimization. Collaborate with recruiting to attract and retain top talent aligned with Growth’s fast-paced, outcome-driven environment. Monitor team performance proactively, ensuring strong execution and continuous improvement. Support engineers in delivering measurable impact and developing their careers through ownership of key growth metrics. Navigate difficult conversations with clarity and empathy, especially when balancing business urgency with technical quality. Foster a collaborative, high-velocity team culture aligned with company goals. Team you would be leading – Growth The Growth team is dedicated to driving high NDR and sustainable revenue growth through

ABOUT THE TEAM The Canvas Core team builds and maintains the foundational platform that powers Mural’s visual thinking experience. This includes the infinite canvas, key editor components, document editing behaviors, asset management, real-time collaboration, and the systems that enable fast, reliable, and intuitive interaction on the canvas. We’re also responsible for the Mural UI, the real-time message protocol that enables seamless remote collaboration, and the developer-friendly APIs that internal teams use to build features like diagramming, workshops, presentations, integrations, and AI-enabled product capabilities. Our mission is to ensure the Mural editor is fast, reliable, intuitive, and easy to build on. We prioritize performance, simplicity, developer experience, and platform quality, enabling teams across the company to ship quickly and safely on top of Canvas Core. YOUR MISSION As a Senior Software Engineer, you’ll help design, build, and improve the Canvas platform so that the Mural editor remains reliable, high-performing, and intuitive for our users. You’ll work on the systems that power real-time collaboration, shared document editing, spatial interactions, rendering and interaction performance, asset management, developer APIs, and AI-enabled product capabilities across the Mural editor. Your role will be to reduce platform complexity, improve the quality and speed of Canvas development, and help teams ship high-quality editor experiences quickly and safely. You’ll partner closely with Product, Design, Engineering, and other stakeholders to turn ambiguous product and platform problems into clear, maintainable technical solutions. Senior Engineers at Mural lead by example through strong technical execution, thoughtful design, high-quality implementation, and collaborative problem-solving. They help raise the bar for their team through design discussions, code reviews, mentoring, documentation, and pragmatic improvements to engineering practices. WHA

Replit is the agentic software creation platform that enables anyone to build applications using natural language. With millions of users worldwide, Replit is democratizing software development by removing traditional barriers to application creation. About the role: Join our Site Reliability Engineering team and help ensure the reliability, scalability, and performance of Replit's infrastructure that serves millions of developers worldwide. As a Site Reliability Engineer, you will bridge the gap between development and operations, implementing automation and establishing best practices that enable our platform to scale efficiently while maintaining high availability. We are seeking SREs who are passionate about building and maintaining resilient systems at scale. Your mission will be to design and implement robust monitoring solutions, automate operational tasks, and continuously improve our infrastructure's reliability and performance. You will: Design and Implement Observability Solutions : Develop comprehensive monitoring and alerting systems using modern observability tools. Create dashboards and metrics that provide real-time visibility into system health and performance. Implement logging strategies that enable quick problem identification and resolution. Drive Automation and Infrastructure as Code : Architect and implement infrastructure automation solutions using tools like Terraform, Ansible, or Pulumi. Design and maintain CI/CD pipelines that enable reliable and consistent deployments. Create self-healing systems that can automatically respond to common failure scenarios. Establish SLOs and SLIs : Work with product and engineering teams to define and implement Service Level Objectives (SLOs) and Service Level Indicators (SLIs). Build systems to track and report on these metrics, ensuring we maintain high reliability standards while balancing innovation speed. Incident Management and Response : Lead incident response efforts, conducting thorough post-morte

About Mixpanel Mixpanel is the leading product intelligence and analytics platform, trusted by more than 29,000 companies to help understand how people use the products they build. By combining powerful analytics with AI that knows your business, Mixpanel helps teams see what’s working, diagnose what’s not, and decide what to build next. Learn more at mixpanel.com . About the Customer Engineering Team Mixpanel’s Customer Engineering teams are analytics consultants who embed themselves within our enterprise customer teams to drive business outcomes. We work with prospects and customers throughout the customer journey to understand what drives value, and serve as the technical counterpart to our Sales organisation to deliver on that value. You will partner closely with Account Executives, Customer Value Architects, Product, Engineering, and Support to successfully roll out self-serve analytics within our customers’ organisations, help manage change, execute on technical projects and services that delight our customers, and ultimately drive ROI on the customer’s Mixpanel investment. About the Role Our Customer Engineers are inquisitive, nimble, and able to clearly articulate the technical benefits and requirements of Mixpanel to developers and product managers, while also communicating the business value of our product to senior executives. In your first month, you’ll become a Mixpanel expert—both in features and functionality as well as implementation. You’ll shadow customer calls and demos with current Customer Engineers and Account Executives while learning to articulate our value proposition, and be trained on Mixpanel’s internal systems and tools. Within your first three months, you’ll be directly involved in deal cycles with Account Executives across the ANZ region. You’ll lead the technical qualification for customer use cases and deliver customised demos for prospects and existing customers, working directly with leadership at the prospect’s organisation to und

About Mixpanel Mixpanel is the leading product intelligence and analytics platform, trusted by more than 29,000 companies to help understand how people use the products they build. By combining powerful analytics with AI that knows your business, Mixpanel helps teams see what’s working, diagnose what’s not, and decide what to build next. Learn more at mixpanel.com . About the Team The Proactive Insights team is a newly formed team at the center of Mixpanel's AI-first analytics vision. With a greenfield charter, we're building the intelligent layer that transforms Mixpanel from a tool you query into a partner that works for you. We answer the question every data-driven team asks: "What changed, why, and what should I do about it?" We proactively keep users informed about what matters in their data, delivering the right insights and recommendations at the right time, to the right places, both inside and outside of Mixpanel. Some examples of what we are building: AI-powered root cause analysis : intelligent agents that diagnose why metrics changed, identify contributing factors, and recommend what to do next AI automations for KPI monitoring : always-on agents that track your key metrics and deliver insights to Slack, email, or directly in Mixpanel Intelligent alerts and anomaly detection : monitoring powered by models like TimesFM that surfaces meaningful shifts in your data About the Role As a Software Engineer on Proactive Insights, you'll build the features that transform how teams stay on top of their data. You'll work across the full stack, from React frontend experiences to Python backend services to integrating with our query engine, to ship workflows that surface insights users didn't know to ask for. You'll collaborate closely with Product and Design to shape what proactive analytics looks like, and with our AI Engine team to leverage shared infrastructure for orchestration, evaluation, and observability. This is a high-impact role on a small, fast-moving tea

About Mixpanel Mixpanel is the leading product intelligence and analytics platform, trusted by more than 29,000 companies to help understand how people use the products they build. By combining powerful analytics with AI that knows your business, Mixpanel helps teams see what’s working, diagnose what’s not, and decide what to build next. Learn more at mixpanel.com . About The Role Data governance is one of the most critical challenges for Mixpanel's enterprise customers, and the AI era turns it into a foundational problem. Analytics and agents are only as trustworthy as the data beneath them. Poor data quality compounds: incorrect analyses spread as it becomes easier for anyone — or any agent — to query data, and the problem multiplies as customers scale into projects with high-cardinality events and fast-growing user bases. A data foundation that stays clean, consistent, and trusted is what sets Mixpanel apart. As a Senior Software Engineer on the Data Foundation team, you'll work across the stack to build high-impact features with extreme customer focus. You'll partner closely with engineers across the company, and with Design, Product, and GTM, to solve one of the hardest problems in analytics: keeping data clean, consistent, and trustworthy at scale. Curious what this looks like in practice? Read why data governance matters for AI-powered analytics on our blog. What You'll Do Build customer-facing features on our web application (React SPA) Collaborate closely with engineers and cross-functional partners across Product, Design, GTM, and beyond Take full ownership of projects — from shaping and delivery through iteration We're Looking For Someone Who Has Full-stack experience, with deep expertise in at least one of: Web application backends (Python, Django) High-volume APIs Search indexing A track record of leading projects end to end, not just executing tickets Comfort moving across the stack Bonus Points For Experience with data ingestion (Go) A data-driv

About Mixpanel Mixpanel is the leading product intelligence and analytics platform, trusted by more than 29,000 companies to help understand how people use the products they build. By combining powerful analytics with AI that knows your business, Mixpanel helps teams see what’s working, diagnose what’s not, and decide what to build next. Learn more at mixpanel.com . About the Information Security Team We believe security isn't just a function—it's a platform for bold ideas. The Information Security Team at Mixpanel is a small, high-impact group committed to building a frictionless security program that serves as a model for our company and the broader industry. This is a team for those who are never satisfied, who dream big, and who have the resilience to see those ideas through. We operate at the intersection of business strategy and technical execution, where we are critical partners to every team at Mixpanel. Our work requires a broad, generalist skill set across vulnerability management, threat detection, and access management. We strategically balance necessary compliance work with proactive initiatives, with a constant focus on automation as the path to a more efficient security program. We use our expertise in a variety of well-known security platforms and tools to create seamless, automated processes that empower our peers. We are a lean team by design, and we succeed or fail together, committed to transparent communication and a strong sense of ownership. Responsibilities Domain Ownership: Serve as the domain expert for Detection & Response, integrating telemetry from across our entire ecosystem—including Product, Cloud, Corporate Infrastructure, and Identity—to build a unified, high-fidelity detection and response engine. Technical Project Execution: Translate high-level project requirements and technical scoping documents into actionable milestones, managing task delivery and driving cross-functional results. Architect Modern Detection: Design and imp

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 with trillions of data points per day, enabling seamless collaboration and problem-solving among Dev, Ops, and Security teams for tens of thousands of companies globally. Our engineering culture values pragmatism, honesty, and simplicity to solve hard problems the right way. The Team The Datadog Security Libraries team owns the customer-side integrations behind our run-time security products App & API Protection , Workload Protection , and Code Security . Our libraries let customers automatically manage application security risk with continuous, real-time monitoring of vulnerabilities and threats against their web applications, serverless applications, and APIs, in production. Automatically integrated with Application Performance Monitoring (APM) distributed tracing and code-level context, our software empowers development, operations, and security teams to build and run secure applications. As a polyglot team we ship and maintain the security capabilities of Datadog's tracing libraries across .NET , Java , Go , Node.js , Python , Ruby , and PHP , on top of a shared C++ core and a set of HTTP proxy integrations (primarily Envoy, NGINX, and HAProxy). Our code runs inside thousands of production applications around the world. Recent work spans exploit prevention (RASP) and WAF detections, API Security, code security (IAST and SCA), and AI-assisted ("agentic") onboarding, always measured by real product outcomes and operational telemetry. The Opportunity We're looking for a senior, polyglot engineer to contribute across several of our security libraries, with .NET or Java expertise. You'll design and build security integrations and detection features, take them from prototype to production-hardened, and own them operationally as they instrument thousands of applications. As a se

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 with trillions of data points per day, enabling seamless collaboration and problem-solving among Dev, Ops, and Security teams for tens of thousands of companies globally. Our engineering culture values pragmatism, honesty, and simplicity to solve hard problems the right way. The Team The Datadog Security Libraries team owns the customer-side integrations behind our run-time security products App & API Protection , Workload Protection , and Code Security . Our libraries let customers automatically manage application security risk with continuous, real-time monitoring of vulnerabilities and threats against their web applications, serverless applications, and APIs, in production. Automatically integrated with Application Performance Monitoring (APM) distributed tracing and code-level context, our software empowers development, operations, and security teams to build and run secure applications. As a polyglot team we ship and maintain the security capabilities of Datadog's tracing libraries across .NET , Java , Go , Node.js , Python , Ruby , and PHP , on top of a shared C++ core and a set of HTTP proxy integrations (primarily Envoy, NGINX, and HAProxy). Our code runs inside thousands of production applications around the world. Recent work spans exploit prevention (RASP) and WAF detections, API Security, code security (IAST and SCA), and AI-assisted ("agentic") onboarding, always measured by real product outcomes and operational telemetry. The Opportunity We're looking for a senior, polyglot engineer to contribute across several of our security libraries, with .NET or Java expertise. You'll design and build security integrations and detection features, take them from prototype to production-hardened, and own them operationally as they instrument thousands of applications. As a se

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

Secure Every Identity, from AI to Human Identity is the key to unlocking the potential of AI. Okta secures AI by building the trusted, neutral infrastructure that enables organizations to safely embrace this new era. This work requires a relentless drive to solve complex challenges with real-world stakes. We are looking for builders and owners who operate with speed and urgency and execute with excellence. This is an opportunity to do career-defining work. We're all in on this mission. If you are too, let's talk. The Classified Senior Software Engineer in Test Opportunity We are seeking a highly specialized and experienced individual for a critical Software Engineer in Test role within a restricted environment. This position is vital for the validation and certification of all platform releases, ensuring customer-critical flows remain intact and reliable. This role requires a unique blend of testing acumen, operational experience, and system-level understanding. The successful candidate will serve as the sole Quality assurance resource in this environment, requiring them to wear multiple hats across the software lifecycle—from understanding the underlying product infrastructure and release versioning to certifying the final product. A passion for ensuring the uptime and reliability of large-scale, mission-critical software is paramount. What you’ll be doing Analyze/refine requirements with Development and Engineering Leads, focusing on test planning and scope to certify releases. Participate effectively in a scrum team environment. Manage deliverables working under minimal supervision. Partner with Development and Release Teams to build and execute on product infrastructure growth and high availability. Understand Okta’s top customers usage patterns to define critical test coverage. Review new changes going into test and staging environments. Ensure new changes are compatible with existing customer deployments and usage. Develop, maintain, and debug end-to-end

About Ema Ema is building the world’s leading Agentic AI platform to transform enterprise productivity. We enable organizations to delegate repetitive tasks to Ema, the Universal AI Employee, delivering 10x gains in workforce efficiency, across functions. Founded by former executives from Google, Coinbase, Flipkart, and Okta, our team includes engineers from premier tech companies and graduates of Stanford, MIT, UC Berkeley, CMU, and IITs. We are backed by industry leading investors including Accel, Naspers/Prosus, Section32, and angels like Sheryl Sandberg and Dustin Moskovitz. Headquartered in Silicon Valley and with offices in London, Bangalore and Vancouver, Ema is at the frontier of what Agentic AI can do in production — we ship real systems that run real business processes at scale. Who you are You are an experienced Infrastructure Engineer Engineer who owns backend infrastructure end to end. You design multi-tenant, microservices-based systems that other engineering teams build on, and you make deliberate architectural tradeoffs around consistency, latency, scale, and cost. You are comfortable going deep — service mesh internals, database internals, distributed-systems failure modes — and equally comfortable defining the reliability and security contracts an enterprise AI platform depends on. Responsibilities Design, own, and evolve scalable microservices architectures on Kubernetes across GCP, Azure, and AWS, including multi-tenant isolation (namespaces, network policies, per-tenant resource quotas and RBAC). Build core platform and data-plane components in Golang and Python — data ingestion, knowledge-base indexing and vector/graph search, application connectivity, workflow automation, and ML operations — against explicit latency and throughput SLOs. Own service-to-service communication: gRPC/protobuf API contracts, service mesh (Istio/Linkerd), load balancing, retries, timeouts, and circuit breaking. Make and document architectural tradeoffs — partitioning

At Speechmatics, we’re expanding our user platform offering. We're looking for a Senior Front-End Software Engineer with a strong product mindset to help drive that growth. This is an opportunity to own end-to-end feature development at a leading-edge AI company, from shaping the user experience through to shipping and iterating based on real user feedback and analytics data. What you'll do Own product features from ideation through to delivery, contributing to UX thinking, frontend execution, and post-launch iteration Build polished, accessible user interfaces using React, JavaScript, HTML, and CSS Make UX and UI decisions independently, collaborating closely with designers and PMs rather than waiting on detailed handoffs Design and run A/B tests to validate product decisions and surface insights that improve the user experience Use analytics tooling such as Mixpanel to understand how people interact with the product and feed that learning back into what gets built Partner with backend engineers, product managers, and designers to ship features that genuinely move the needle for users and the business Write and maintain robust UI tests, taking ownership of quality in production and at scale Run user interviews and meet customers to understand how people use the product and what drives adoption What you'll need Proficiency in React, JavaScript, HTML, and CSS with a track record of shipping production-quality frontend code A product-minded engineering approach Comfort owning UX and UI decisions independently Hands-on experience with iterative development practices, including A/B testing and feature experimentation Familiarity with user analytics tools such as Mixpanel or a comparable platform Experience with UI testing frameworks and a solid grounding in frontend engineering best practices Confidence collaborating cross-functionally with designers, PMs, and backend engineers A track record of using user feedback and data to improve features Nice to have Experience us