Software Application Development Engineer Jobs

Who We Are At Justworks, you’ll enjoy a welcoming and casual environment, great benefits, wellness program offerings, company retreats, and the ability to interact with and learn from leaders in the startup community. We work hard and care about our most prized asset - our people. We’re helping businesses get off the ground by enabling them to focus on running their business. We solve HR issues. We’re data-driven and never stop iterating. If you’d like to work in a supportive, entrepreneurial environment, are interested in building something meaningful and having fun while doing it, we’d love to hear from you. We're united by shared goals and shared motivations at Justworks. These are best summed up in our company values, which are reflected in our product and in our team. Our Values If this sounds like you, you’ll fit right in. Who You Are You are self-driven and like to work with others to remove roadblocks. You are curious and love to explore and learn new technologies. You have demonstrated the ability to build, deploy, and maintain large-scale, complex applications. You care more about solutions and impacting the customer experience than using a particular tool or framework. About the role: You will join a small, highly autonomous cross-functional team to build AI agents that fundamentally transform how operations work at scale. Instead of writing bespoke software for every workflow, we are developing an agent platform that can read operational knowledge, reason about it in context, and execute tasks end-to-end. This approach allows us to scale complexity through knowledge and reasoning, rather than simply through code. This is an opportunity to join a foundational team, which currently consists of fewer than five engineers. The work spans critical areas including LLM-powered agent design, robust backend service architecture, tool and integration development, and sophisticated knowledge infrastructure. We are seeking a Senior Software Engineer with a strong pas

Who We Are At Justworks, you’ll enjoy a welcoming and casual environment, great benefits, wellness program offerings, company retreats, and the ability to interact with and learn from leaders in the startup community. We work hard and care about our most prized asset - our people. We’re helping businesses get off the ground by enabling them to focus on running their business. We solve HR issues. We’re data-driven and never stop iterating. If you’d like to work in a supportive, entrepreneurial environment, are interested in building something meaningful and having fun while doing it, we’d love to hear from you. We're united by shared goals and shared motivations at Justworks. These are best summed up in our company values, which are reflected in our product and in our team. Our Values If this sounds like you, you’ll fit right in. Who You Are You are self-driven and like to work with others to remove roadblocks. You are curious and love to explore and learn new technologies. You have demonstrated the ability to build, deploy, and maintain large-scale, complex applications. You care more about solutions and impacting the customer experience than using a particular tool or framework. About the role: You will join a small, highly autonomous cross-functional team to build AI agents that fundamentally transform how operations work at scale. Instead of writing bespoke software for every workflow, we are developing an agent platform that can read operational knowledge, reason about it in context, and execute tasks end-to-end. This approach allows us to scale complexity through knowledge and reasoning, rather than simply through code. This is an opportunity to join a foundational team, which currently consists of fewer than five engineers. The work spans critical areas including LLM-powered agent design, robust backend service architecture, tool and integration development, and sophisticated knowledge infrastructure. We are seeking a Senior Software Engineer with a strong pas

Who We Are At Justworks, you’ll enjoy a welcoming and casual environment, great benefits, wellness program offerings, company retreats, and the ability to interact with and learn from leaders in the startup community. We work hard and care about our most prized asset - our people. We’re helping businesses get off the ground by enabling them to focus on running their business. We solve HR issues. We’re data-driven and never stop iterating. If you’d like to work in a supportive, entrepreneurial environment, are interested in building something meaningful and having fun while doing it, we’d love to hear from you. We're united by shared goals and shared motivations at Justworks. These are best summed up in our company values, which are reflected in our product and in our team. Our Values If this sounds like you, you’ll fit right in. Who You Are You are self-driven and like to work with others to remove roadblocks. You are curious and love to explore and learn new technologies. You have demonstrated the ability to build, deploy, and maintain large-scale, complex applications. You care more about solutions and impacting the customer experience than using a particular tool or framework. About the role: You will join a small, highly autonomous cross-functional team to build AI agents that fundamentally transform how operations work at scale. Instead of writing bespoke software for every workflow, we are developing an agent platform that can read operational knowledge, reason about it in context, and execute tasks end-to-end. This approach allows us to scale complexity through knowledge and reasoning, rather than simply through code. This is an opportunity to join a foundational team, which currently consists of fewer than five engineers. The work spans critical areas including LLM-powered agent design, robust backend service architecture, tool and integration development, and sophisticated knowledge infrastructure. We are seeking a Senior Software Engineer with a strong pas

Who We Are At Justworks, you’ll enjoy a welcoming and casual environment, great benefits, wellness program offerings, company retreats, and the ability to interact with and learn from leaders in the startup community. We work hard and care about our most prized asset - our people. We’re helping businesses get off the ground by enabling them to focus on running their business. We solve HR issues. We’re data-driven and never stop iterating. If you’d like to work in a supportive, entrepreneurial environment, are interested in building something meaningful and having fun while doing it, we’d love to hear from you. We're united by shared goals and shared motivations at Justworks. These are best summed up in our company values, which are reflected in our product and in our team. Our Values If this sounds like you, you’ll fit right in. Who You Are You are self-driven and like to work with others to remove roadblocks. You are curious and love to explore and learn new technologies. You have demonstrated the ability to build, deploy, and maintain large-scale, complex applications. You care more about solutions and impacting the customer experience than using a particular tool or framework. About the role: You will join a small, highly autonomous cross-functional team to build AI agents that fundamentally transform how operations work at scale. Instead of writing bespoke software for every workflow, we are developing an agent platform that can read operational knowledge, reason about it in context, and execute tasks end-to-end. This approach allows us to scale complexity through knowledge and reasoning, rather than simply through code. This is an opportunity to join a foundational team, which currently consists of fewer than five engineers. The work spans critical areas including LLM-powered agent design, robust backend service architecture, tool and integration development, and sophisticated knowledge infrastructure. We are seeking a Senior Software Engineer with a strong pas

Who We Are At Justworks, you’ll enjoy a welcoming and casual environment, great benefits, wellness program offerings, company retreats, and the ability to interact with and learn from leaders in the startup community. We work hard and care about our most prized asset - our people. We’re helping businesses get off the ground by enabling them to focus on running their business. We solve HR issues. We’re data-driven and never stop iterating. If you’d like to work in a supportive, entrepreneurial environment, are interested in building something meaningful and having fun while doing it, we’d love to hear from you. We're united by shared goals and shared motivations at Justworks. These are best summed up in our company values, which are reflected in our product and in our team. Our Values If this sounds like you, you’ll fit right in. Who You Are You are self-driven and like to work with others to remove roadblocks. You are curious and love to explore and learn new technologies. You have demonstrated the ability to build, deploy, and maintain large-scale, complex applications. You care more about solutions and impacting the customer experience than using a particular tool or framework. About the role: You will join a small, highly autonomous cross-functional team to build AI agents that fundamentally transform how operations work at scale. Instead of writing bespoke software for every workflow, we are developing an agent platform that can read operational knowledge, reason about it in context, and execute tasks end-to-end. This approach allows us to scale complexity through knowledge and reasoning, rather than simply through code. This is an opportunity to join a foundational team, which currently consists of fewer than five engineers. The work spans critical areas including LLM-powered agent design, robust backend service architecture, tool and integration development, and sophisticated knowledge infrastructure. We are seeking a Senior Software Engineer with a strong pas

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 Principal 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 and visionary Principal Engineer to join our team and lead the design and development of our Data Platform. In this role, you will be responsible for architecting scalable and reliable data solutions, driving technical innovation, and mentoring a team of talented engineers. The ideal candidate will have deep exper

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 Principal Software Engineer. About the job This position is needed to lead the planning, design, development, and testing of large-scale software systems and new product capabilities, including cloud and internet-facing services. You’ll set technical direction, drive delivery using modern engineering practices, and ensure what we ship is secure, compliant, and production-ready. You’ll partner closely with product and engineering teams to turn requirements into reliable, high-quality software. Responsibilities In this role, you’ll: Lead architecture and system design for complex, distributed software systems; guide teams toward scalable, maintainable solutions. Design, implement, and review high-quality code for core services, APIs, platforms, and/or user-facing applications. Translate business goals into technical roadmaps, identify tradeoffs, and align stakeholders on solution direction. Improve system resiliency, laten

Our Purpose Mastercard powers economies and empowers people in 200+ countries and territories worldwide. Together with our customers, we’re helping build a sustainable economy where everyone can prosper. We support a wide range of digital payments choices, making transactions secure, simple, smart and accessible. Our technology and innovation, partnerships and networks combine to deliver a unique set of products and services that help people, businesses and governments realize their greatest potential. Title and Summary Lead Software Engineer - Java Are you an experienced software engineer who enjoys solving complex technical challenges and helping others build better solutions? As a Lead Software Engineer, you will design, build, and operate secure, scalable, and resilient technology that supports important payment services. You will combine hands-on development with technical leadership and work closely with teams across product, operations, architecture, infrastructure, risk, and customer-facing functions. Mastercard Payment Services: In Mastercard Payment Services, you will contribute to critical European payment clearing and settlement services. This includes real-time and batch clearing, instant payments, participant-facing services, liquidity and settlement capabilities, reporting, and related payment infrastructure. You will help ensure these services are reliable, secure, and resilient by applying strong engineering practices, automation, production ownership, and continuous improvement. What you will do: • Design, build, integrate, and improve secure, scalable applications and services. • Take ownership of complex service issues and coordinate resolution across teams. • Work with product partners and stakeholders on priorities, trade-offs, and technical roadmaps. • Improve delivery quality through a

Our Purpose Mastercard powers economies and empowers people in 200+ countries and territories worldwide. Together with our customers, we’re helping build a sustainable economy where everyone can prosper. We support a wide range of digital payments choices, making transactions secure, simple, smart and accessible. Our technology and innovation, partnerships and networks combine to deliver a unique set of products and services that help people, businesses and governments realize their greatest potential. Title and Summary Lead Software Engineer - Java Are you an experienced software engineer who enjoys solving complex technical challenges and helping others build better solutions? As a Lead Software Engineer, you will design, build, and operate secure, scalable, and resilient technology that supports important payment services. You will combine hands-on development with technical leadership and work closely with teams across product, operations, architecture, infrastructure, risk, and customer-facing functions. Mastercard Payment Services: In Mastercard Payment Services, you will contribute to critical European payment clearing and settlement services. This includes real-time and batch clearing, instant payments, participant-facing services, liquidity and settlement capabilities, reporting, and related payment infrastructure. You will help ensure these services are reliable, secure, and resilient by applying strong engineering practices, automation, production ownership, and continuous improvement. What you will do: • Design, build, integrate, and improve secure, scalable applications and services. • Take ownership of complex service issues and coordinate resolution across teams. • Work with product partners and stakeholders on priorities, trade-offs, and technical roadmaps. • Improve delivery quality through a

Couchbase, the operational data platform for AI, empowers businesses to succeed by bringing data to life in new ways. Major market-leading companies rely on Couchbase for mission critical operational, analytical, mobile and AI workloads. Built to replace legacy infrastructure and fragmented data services, Couchbase empowers enterprises with a unified platform architected for performance, flexibility and global scale. With Couchbase, organizations bring their data to life, launching game‑changing customer experiences, exploring the limitless potential of AI, and seamlessly extending applications from the cloud to the edge and beyond. Couchbase’s AI‑ready technology and enterprise partnership model eliminate complexity and reduce total cost of ownership, enabling teams to stay agile, innovative and secure. Couchbase believes data should never slow you down, but act as the foundation for your next breakthrough. Discover why Couchbase is trusted to help the world’s biggest players scale, move fast and stay resilient, no matter what’s next on their roadmap. Visit couchbase.com and follow us on LinkedIn and X. Want to be part of our story? Apply today! Lead Software Engineer - Storage As a key contributing member of the storage development team, you will be responsible for enhancing the highly scalable and performant storage engines used by both Couchbase Server and Couchbase Capella. You will be developing a highly-available and concurrent enterprise-grade system software. Most of all, you will be able to celebrate the wins by experiencing the direct result of your hard work from our customers’ success stories. The ideal candidate will have a strong technical background, excellent communication skills, and proactive problem-solving skills. The innovative work storage team does has been widely recognized by the industry. The following publications in VLDB conferences reflect the storage work at Couchbase Nitro: A Fast, Scalable In-Memory Storage Engine for NoS

Identity has become a critical to an organizations security posture. This is true across their entire digital landscape include cloud, traditional on prem and emerging technologies like agentic ai. Britive is at the forefront of a modern approach to delivering identity security with the only modern privileged access management platform that provides unified Privileged Access Visibility, Dynamic Privilege Management and Secrets Governance across infrastructure, platforms & SaaS. Our patent-pending technology is deployed at companies of all sizes around the world, including Fortune 500 companies. We have repeatedly ranked among the hottest Cloud Security startups. Britive is founded by CyberSecurity industry veterans with a successful prior exit and is backed by top-tier VCs. About You You are a passionate Senior Software Engineer who wants to develop and scale our multi-tenant SaaS applications on the AWS platform. You have strong hands-on technical expertise in a variety of big data technologies. From day one, you must be able to hit the ground running and bring all your experience to the team to contribute in the building of a great product. Most importantly, you have a positive “can do” attitude and a passion for delivering technical solutions in a fast-paced startup environment. Your Impact Key Responsibilities: Responsible for design and development of a large-scale data ingestion and analytics. Design and develop data pipelines for real-time and batch data processing for disparate datasets. Develop systems which can store data in highly normalized fashion to allow correlation with other data sources. Collaborate with product management and engineering teams to design and integrate software, conduct code reviews, and troubleshoot product issues. Perform proof of concepts to identify best design options including usage of AWS services. Resear

Scale’s rapidly growing International Public Sector team is focused on using AI to address critical challenges facing the public sector around the world. Our core work consists of: Creating custom AI applications that will impact millions of citizens Generating high-quality training data for custom LLMs Upskilling and advisory services to spread the impact of AI As a Full Stack Software Engineer (Forward Deployed), you’ll collaborate directly with public sector counterparts to quickly build full-stack, AI applications, to solve their most pressing challenges and achieve meaningful impact for citizens. At Scale, we’re not just building AI solutions—we’re enabling the public sector to transform their operations and better serve citizens through cutting-edge technology. If you’re ready to shape the future of AI in the public sector and be a founding member of our team, we’d love to hear from you. You will: Serve as the lead technical strategist for public sector engagements, converting ambiguous mission requirements into robust architectural roadmaps and guiding onsite implementation Architect the fundamental frameworks for production-grade AI applications, setting the gold standard for how interactive UIs, backend systems, and AI models are integrated at scale to deliver reliable outcomes. Guide the evolution of cloud infrastructure, ensuring security, global scalability, and long-term system integrity across all environments. Direct the development of core platforms and shared services, ensuring they solve cross-cutting needs for diverse global client use cases. Partner with cross-functional leadership to steer the technical roadmap, mentoring senior and junior staff and ensuring all products align with a cohesive, future-proof technical architecture. Bridge the gap between the field and the core platform by turning real-world client lessons into the reusable patterns that power the entire engineering team. Ideally you’d have: Masters or Phd in Computer Science or eq

The Public Sector software engineers (SWEs) create the core product building blocks forward-deployed teams use to develop agentic capabilities that function across multiple domains. SWEs responsibilities include building the systems required to ingest and process federal datasets to support real-time decision-making in contested environments. We develop novel agentic enabling capabilities that includes: Create multi-layered guardrails around agents Optimize data retrieval for agents Orchestrate fleets of asynchronous agents Automatically alerts users to deviations in data Illustrating how an agent reached a decision As a Senior Software Engineer, you will lead the development of a vertical feature or a horizontal capability to include defining requirements with stakeholders and implementation until it is accepted by the stakeholders. You will: Lead the design and implementation of scalable backend systems and distributed architectures for Federal customers. Manage the full lifecycle of feature development from requirement definition to deployment on classified networks. Direct the orchestration of asynchronous agent fleets to meet mission requirements. Lead customer engagements to translate mission needs into technical requirements. Own the communication with stakeholders to ensure implementation meets defined acceptance criteria. Conduct technical reviews and identify risks within machine learning infrastructure and model serving. Drive the platform roadmap by providing technical specifications for Federal product offerings. Ideally you will have: Full Stack Development: Proficiency in front-end, back-end development and infrastructure, including experience with modern web development frameworks, programming languages, and databases Cloud-Native Technologies: Familiarity with cloud platforms (e.g., AWS, Azure, GCP) and experience in developing and deploying applications in a cloud-native environment. Understanding of containerization (e.g., Docker) and contai

At Scale, our mission is to develop reliable AI systems for the world's most important decisions. For 10 years, Scale has provided the high-quality data and full-stack technologies that power the world's leading models, and has helped enterprises and governments build, deploy, and oversee AI applications that deliver real impact. We work closely with industry leaders like Meta, Ernst & Young, Mayo Clinic, Time Inc., the Government of Qatar, and U.S. government agencies including the Army and Air Force. Scale's internship is not a side project. Interns own real, shipped work on the same roadmaps as full-time engineers, with mentorship from world-class talent and a culture that values ownership, speed, and truth-seeking. Many of our interns return as full-time Scaliens. Example Projects Build reinforcement learning and post-training data pipelines that power frontier model development Develop evaluation infrastructure that measures model reliability for enterprise and public sector customers Ship agentic AI applications and the tooling that makes them observable, testable, and safe to deploy Ship tools that accelerate the growth of new qualified contributors on Scale's platform Build fraud-detection systems that remove bad actors and keep Scale's contributor base safe and trusted Use models to estimate the quality of tasks and contributors, and guarantee quality on requests at large scale Devise advanced matching algorithms that pair contributors to customers for optimal turnaround and accuracy Create optimized and efficient UI/UX tooling, in combination with ML algorithms, for 100k+ contributors completing billions of complex tasks Develop new AI infrastructure products to visualize, query, and explore Scale data Requirements A graduation date in Fall 2027 or Spring 2028 with a Bachelor's degree (or equivalent) in a relevant field (Computer Science, EECS, Computer Engineering, Statistics) Available for a Summer 2027 internship (May/June start dates) in San Franci

Scale GP (Scale Generative AI Platform) is an enterprise-grade Generative AI platform providing APIs for knowledge retrieval, inference, evaluation, and more. We are seeking a strong Senior Full-Stack Engineer to help us build, scale, and refine our rapidly growing product. The ideal candidate is deeply grounded in software engineering best practices and experienced in developing and scaling modern web applications end-to-end. You will work across the stack—from React/TypeScript frontends to Python-based backends—while integrating with LLMs and machine learning systems. You will solve complex challenges in scalability, reliability, and product experience while owning significant product areas in a fast-paced environment. What You’ll Do Own major full-stack product areas , driving features from design through production deployment. Build modern frontend experiences using React and TypeScript, ensuring performance, usability, and responsiveness. Develop reliable backend services in Python, working with distributed systems, data pipelines, and ML/LLM components. Integrate with LLMs, vector databases, and AI infrastructure to power intelligent product experiences. Deliver experiments and new features quickly , maintaining high quality and tight feedback loops with customers. Collaborate across product, ML, and infrastructure teams to shape the direction of Scale GP. Adapt quickly —learning new technologies, frameworks, and tools as needed across the stack. Ideal Experience 5+ years of full-time engineering experience , post-graduation. Strong experience developing full-stack applications using React, TypeScript, and Python . Experience scaling or shipping products at high-growth startups . Familiarity with LLMs, vector databases, embeddings, or other modern AI tooling (tinkering or production experience welcome). Proficiency with SQL and modern API development. Experience with Kubernetes , containerization, and microservice architectures. Experience working with at leas