Senior Backend Software Engineer Application Development Jobs

This is Adyen Adyen provides payments, data, and financial products in a single solution for customers like Meta, Uber, H&M, and Microsoft - making us the financial technology platform of choice. At Adyen, everything we do is engineered for ambition. For our teams, we create an environment with opportunities for our people to succeed, backed by the culture and support to ensure they are enabled to truly own their careers. We are motivated individuals who tackle unique technical challenges at scale and solve them as a team. Together, we deliver innovative and ethical solutions that help businesses achieve their ambitions faster. Documentation Tooling Team The Documentation Tooling Team is responsible for building the systems and foundations that improve how technical knowledge is created, structured, and delivered across Adyen’s developer ecosystem. You will work on core challenges related to content quality, freshness, consistency, scalability and the ability to make information usable both for people and agents. In this role, you will build the next generation of Adyen’s knowledge platform. This platform turns static documentation into structured, queryable knowledge.This includes structuring content, connecting content from multiple sources and building interfaces that make technical documentation accessible across products and tools as knowledge. Your work will power reliable, contextual and efficient access to information for customers, developers, AI agents and internal teams. The team is a strategic part of the Developer Experience group within the Customer Experience solution. Our mission is to provide clear, accurate, and accessible knowledge that supports customers throughout their integration journey and helps them move quickly with confidence. Core Focus Area Content Architecture: Design scalable graph schemas, ontologies, and metadata models that support consistency, reuse, and discoverability across documentation. Serverless Pipeline Orchestra

For more than 30 years, SonicWall has delivered a partner-first unified cybersecurity portfolio that helps SMBs, MSPs, and IT teams consolidate network security, endpoint security, security service edge (SSE), and threat response across hybrid environments. By bringing connected technology, real-time threat intelligence, automation, and expert services together, SonicWall helps organizations simplify security operations, achieve better security outcomes, and lower total cost of ownership. Backed by a global ecosystem of more than 17,000 partners, SonicWall delivers enterprise-grade protection built for SMB and mid-market realities. For more information, visit www.sonicwall.com or follow us on X, LinkedIn , Facebook , and Instagram . About the Role SonicWall is hiring a Senior Software Engineer to develop and maintain the Content Filtering Service client embedded in SonicOS — the firmware running on SonicWall firewall appliances worldwide. This module intercepts live traffic, queries the CFS rating servers in real time, and enforces URL-based content filtering policies at the packet level. This is security-critical code: a policy bug is a traffic bypass on a deployed security appliance. The codebase is in C with a split Control Plane / Data Plane architecture, multi-blade cache synchronization, and multiple firmware version upgrade paths. Responsibilities Maintain, harden, and extend the CFS client module across both the control plane and data plane. Own the binary UDP protocol implementation between the firewall and the CFS rating servers, ensuring correctness and compatibility across protocol versions. Develop and maintain complete IPv4 and IPv6 support across all code paths. Own the firmware upgrade and migration paths, ensuring they are atomic, failure-safe, and correctly handle all supported version transitions. Improve reliability of inter-blade cache synchronization on multi-blade appliances. Collaborate with the server-side on coordinated

Forward is transforming how the world’s most complex networks are managed and secured. Founded in 2013 by four Stanford Ph.D.s, we built the industry’s first network digital twin — a mathematically precise model of the production network that gives IT teams unmatched visibility, verification, and agility across every major cloud and vendor environment. Our customers include global leaders such as Goldman Sachs, PayPal, S&P Global, IBM, and Dell, as well as fast-growing enterprises and government agencies. According to IDC, Forward customers realize an average of $14.2 million in annual benefits through improved efficiency and security. Backed by world-class investors including Andreessen Horowitz, Goldman Sachs, MSD Partners, and Threshold Ventures, Forward offers a people-centric, innovative culture where brilliant minds are shaping the future of network reliability, security, and AI-ready operations. Forward is currently seeking experienced Java developers to work as part of our Network team. Responsibilities Help bring the best ideas from the software development world into the networking industry. Contribute to our code base, systems and software architecture as a member of our engineering team. Help create and optimize network device models for different device vendors and protocols. Help create infrastructure needed to configure, collect and test network devices. Work with peers who are experts in Networking, Distributed Systems, Big Data and Search. Requirements 5+ years of work experience in software development 3+ years of work experience with Java BS in Computer Science or related degree Solid software engineering experience with large code bases Basic understanding of networking and TCP/IP. Strong verbal and written communication skills. Nice to haves Working knowledge of how switches, routers, firewalls or load balancers work. Experience working with networking protocols such as BGP/OSPF/IS-IS, IPv4/IPv6, MPLS, VLAN, VXLAN, etc. This position is a re

At Secureframe , we are not just a company; we are at the forefront of revolutionizing cybersecurity compliance. Recognized as one of the industry's most innovative and trusted providers, Secureframe has consistently received accolades for our advanced technology solutions and commitment to excellence. With a robust portfolio of products that safeguard thousands of businesses worldwide, we have been featured in major publications such as Forbes’ next billion dollar startups , TechCrunch, and The Wall Street Journal for our transformative impact on the way companies achieve and maintain compliance standards. As we continue to grow, our mission remains clear: to provide seamless, secure solutions that enable businesses to focus on what they do best. Joining Secureframe means becoming part of a team dedicated to professional excellence and continuous learning in an environment that values creativity and forward-thinking. Secureframe is backed by top VCs including Kleiner Perkins, Accomplice, Gradient Ventures (Google’s AI Fund), BoxGroup, Village Global, and many more. About the role We are an impactful, highly collaborative team dedicated to advancing the field of security and compliance. As we strive for excellence, every team member plays a pivotal role in shaping our team's dynamics and culture. We value ownership and provide substantial responsibilities that offer our team members the opportunity to have a critical impact on our continued growth. This is a hybrid position in NYC. Secureframe highly values having employees working in-office to foster a collaborative work environment and company culture. For office-based employees (employees who live within a defined radius of a Secureframe office), Secureframe considers working in the office, approximately 30% of the time under current policy, to be an essential function of the employee's role. Benefits Medical, dental, and vision benefits for you and your dependent(s) Flexible PTO 401(k) Paid family leave Ground f

At Breeze, we're building the AI-powered infrastructure layer for global commerce, making it radically simpler for businesses to sell, get paid, and operate across markets. We go far beyond traditional payment processing. Breeze combines global payments, AI, stablecoins, and a Merchant of Record-like model to take on the complexity businesses typically manage themselves, including compliance, risk, fraud, chargebacks, reconciliation, and customer support. Our goal is simple: let businesses focus on building and selling great products while Breeze handles the complexity behind getting paid. Backed by Sequoia Capital , Multicoin Capital , and The Chainsmokers , Breeze is a successful, rapidly growing, and exceptionally well-capitalized company. We have the runway to think long term while remaining early enough that every person joining today can have a meaningful impact on what we build. Overview Want to build products that sit at the heart of how money moves? We’re looking for a Senior Software Engineer to help build and scale the technology powering Breeze. This is a hands-on role with real ownership. You’ll tackle complex engineering challenges, ship products customers rely on every day, and help shape technical decisions as we scale. You’ll work across the stack, partner closely with Product and Design, and have plenty of white space to improve how we build. We’re looking for an engineer who combines strong technical judgment with a product mindset. Someone who moves fast, cares deeply about quality, and gets excited about turning complex payments problems into simple, reliable experiences. If you want to build, not just maintain, and have a meaningful impact on both our product and engineering culture, we’d love to meet you. What You’ll Do Build and scale the core payment systems that power Breeze, with a focus on reliability, security, and performance Ship high-quality customer experiences using React.js and modern serverless infrastructure Own meaningful featur

This is Adyen Adyen provides payments, data, and financial products in a single solution for customers like Meta, Uber, H&M, and Microsoft - making us the financial technology platform of choice. At Adyen, everything we do is engineered for ambition. For our teams, we create an environment with opportunities for our people to succeed, backed by the culture and support to ensure they are enabled to truly own their careers. We are motivated individuals who tackle unique technical challenges at scale and solve them as a team. Together, we deliver innovative and ethical solutions that help businesses achieve their ambitions faster. Senior Software Engineer, Lending Build lending at Adyen from the first line of code. Businesses run on Adyen: they accept payments, manage their money and issue cards on our platform. Access to capital has been the missing piece, and we're building it now. Lending at Adyen is a brand-new team, and we're looking for the engineers who will lay its foundations. Our advantage is data. We already see how a business actually performs through its payment flows, so we can offer fast, fair financing, embedded directly in the platforms our customers use every day. That lets us serve businesses that traditional lenders overlook, without the long paperwork process. This is a true zero-to-one opportunity. There's no legacy system to maintain and no roadmap handed down from above. You'll help decide what we build, how we build it, and which trade-offs we make. You'll be part of a small team with the backing, scale and customer base of a global company. What you’ll do: Design and build core lending systems from scratch, including loan origination, underwriting and decisioning engines, repayment flows and the ledgers that track every cent. Turn ambiguous problems into shipped products, working closely with product, risk, finance and legal partners. Make foundational architecture decisions that will shape how lending scales across markets an

About Decagon Decagon is the leading conversational AI platform empowering every brand to deliver concierge customer experiences. Our technology enables industry-defining enterprises like Avis Budget Group, Block’s Cash App and Square, Chime, Oura Health, and Hunter Douglas to deploy AI agents that power personalized, deeply satisfying interactions across voice, chat, email, SMS, and every other channel. We’re building a future where customer experiences are being redefined from support tickets and hold music to faster resolutions, richer conversations, and deeper relationships. We’re proud to be backed by world-class investors who share that vision, including a16z, Accel, Bain Capital Ventures, Coatue, and Index Ventures, along with many others. We’re an in-office company, driven by a shared commitment to excellence and velocity. Our values — Just Get It Done, Invent What Customers Want, Winner’s Mindset, and The Polymath Principle — shape how we work and grow as a team. About the Team The Agent Product Engineering team at Decagon deploys mission-critical AI agents to our customers that impact millions of users and directly drive Decagon’s growth. You will build on our industry-leading AI agent platform, collaborate directly with customers and use your own creativity to devise long-term, scalable solutions. Our mission is to deliver magical support experiences — AI agents working alongside human agents to help users resolve their issues. About the Role On the Agent Product Engineering team, you’ll have complete ownership and autonomy in building and shipping best-in-class AI agents, from initial implementation through continuous iteration. You’ll work directly with leaders across industries like finance, healthcare and hospitality, solving their users’ needs with reliable and intuitive AI agents. Engineers here own their work end-to-end and are trusted to make a real impact. This role is for someone who dives deep into complex system challenges and builds elegant s

About Decagon Decagon is the leading conversational AI platform empowering every brand to deliver concierge customer experiences. Our technology enables industry-defining enterprises like Avis Budget Group, Block’s Cash App and Square, Chime, Oura Health, and Hunter Douglas to deploy AI agents that power personalized, deeply satisfying interactions across voice, chat, email, SMS, and every other channel. We’re building a future where customer experiences are being redefined from support tickets and hold music to faster resolutions, richer conversations, and deeper relationships. We’re proud to be backed by world-class investors who share that vision, including a16z, Accel, Bain Capital Ventures, Coatue, and Index Ventures, along with many others. We’re an in-office company, driven by a shared commitment to excellence and velocity. Our values — Just Get It Done, Invent What Customers Want, Winner’s Mindset, and The Polymath Principle — shape how we work and grow as a team. About the Team The Agent Product Engineering team at Decagon deploys mission-critical AI agents to our customers that impact millions of users and directly drive Decagon’s growth. You will build on our industry-leading AI agent platform, collaborate directly with customers and use your own creativity to devise long-term, scalable solutions. Our mission is to deliver magical support experiences — AI agents working alongside human agents to help users resolve their issues. About the Role On the Agent Product Engineering team, you’ll have complete ownership and autonomy in building and shipping best-in-class AI agents, from initial implementation through continuous iteration. You’ll work directly with leaders across industries like finance, healthcare and hospitality, solving their users’ needs with reliable and intuitive AI agents. Engineers here own their work end-to-end and are trusted to make a real impact. This role is for someone who dives deep into complex system challenges and builds elegant s

At Breeze, we're building the AI-powered infrastructure layer for global commerce, making it radically simpler for businesses to sell, get paid, and operate across markets. We go far beyond traditional payment processing. Breeze combines global payments, AI, stablecoins, and a Merchant of Record-like model to take on the complexity businesses typically manage themselves, including compliance, risk, fraud, chargebacks, reconciliation, and customer support. Our goal is simple: let businesses focus on building and selling great products while Breeze handles the complexity behind getting paid. Backed by Sequoia Capital , Multicoin Capital , and The Chainsmokers , Breeze is a successful, rapidly growing, and exceptionally well-capitalized company. We have the runway to think long term while remaining early enough that every person joining today can have a meaningful impact on what we build. Overview Want to build products that sit at the heart of how money moves? We’re looking for a Senior Software Engineer to help build and scale the technology powering Breeze. As our first senior engineer in our New York City office, you will be hands-on role with real ownership. You’ll tackle complex engineering challenges, ship products customers rely on every day, and help shape technical decisions as we scale. You’ll work across the stack, partner closely with Product and Design, and have plenty of white space to improve how we build. We’re looking for an engineer who combines strong technical judgment with a product mindset. Someone who moves fast, cares deeply about quality, and gets excited about turning complex payments problems into simple, reliable experiences. If you want to build, not just maintain, and have a meaningful impact on both our product and engineering culture, we’d love to meet you. What You’ll Do Build and scale the core payment systems that power Breeze, with a focus on reliability, security, and performance Ship high-quality customer experiences using React.j

About Decagon Decagon is the leading conversational AI platform empowering every brand to deliver concierge customer experiences. Our technology enables industry-defining enterprises like Avis Budget Group, Block’s Cash App and Square, Chime, Oura Health, and Hunter Douglas to deploy AI agents that power personalized, deeply satisfying interactions across voice, chat, email, SMS, and every other channel. We’re building a future where customer experiences are being redefined from support tickets and hold music to faster resolutions, richer conversations, and deeper relationships. We’re proud to be backed by world-class investors who share that vision, including a16z, Accel, Bain Capital Ventures, Coatue, and Index Ventures, along with many others. We’re an in-office company, driven by a shared commitment to excellence and velocity. Our values — Just Get It Done, Invent What Customers Want, Winner’s Mindset, and The Polymath Principle — shape how we work and grow as a team. About the Team The AI Platform team builds the foundational systems that enable every engineer at Decagon to build with AI. Our users are both engineers and coding agents. We build the execution environments, agent harnesses, evaluation systems, developer tools, and shared abstractions they use to plan, write, test, review, and ship production software. We sit within Infrastructure and work closely with product, ML, data, and security teams. Our goal is to turn rapidly evolving agent capabilities into reliable, secure platforms that materially change how software gets built at Decagon. About the Role We’re looking for an experienced software engineer to help build Decagon’s AI-native developer platform. You’ll work at the intersection of distributed systems, developer tooling, and applied AI. You will experiment with new agentic workflows, identify where they create real leverage, and turn the best ideas into dependable systems used across the engineering organization. This is a highly product-orie

This is Adyen Adyen provides payments, data, and financial products in a single solution for customers like Facebook, Uber, H&M, and Microsoft - making us the financial technology platform of choice. At Adyen, everything we do is engineered for ambition. For our teams, we create an environment with opportunities for our people to succeed, backed by the culture and support to ensure they are enabled to truly own their careers. The people of Adyen are motivated individuals who tackle unique technical challenges at scale and solve them as a team. Together, we deliver innovative and ethical solutions that help businesses achieve their ambitions faster. Financial Products The Financial Products solution is responsible for all financial products that we offer on top of payments processing to our customers. Examples of these are our Banking, Issuing, Fx, and Capital products. Whether we work with large partner platforms, medium sized local merchants, or major international enterprise businesses, our products need to meet our clients expectations and seamlessly fit into their systems. What you’ll do: Work on complex technical projects from requirements analysis through design, implementation, testing and launch into production. Be hands-on and contribute to the implementation. Identify and improve parts of the platform to make it more robust and scalable. Bring your own point of view on best engineering practices. Your code will be used at scale and you are expected to think in that mindset when building features. We launch fast and iterate often. Concretely, this means that within your first few weeks, you will bring live functionalities that impact many merchants and shoppers. Build APIs and tooling according to quality principles such as performance and code quality. Collaborate across teams and time zones to get projects over the finish line. Who you are: Familiar with complex large scale distributed systems. You have experience with Java,

About Decagon Decagon is the leading conversational AI platform empowering every brand to deliver concierge customer experiences. Our technology enables industry-defining enterprises like Avis Budget Group, Block’s Cash App and Square, Chime, Oura Health, and Hunter Douglas to deploy AI agents that power personalized, deeply satisfying interactions across voice, chat, email, SMS, and every other channel. We’re building a future where customer experiences are being redefined from support tickets and hold music to faster resolutions, richer conversations, and deeper relationships. We’re proud to be backed by world-class investors who share that vision, including a16z, Accel, Bain Capital Ventures, Coatue, and Index Ventures, along with many others. We’re an in-office company, driven by a shared commitment to excellence and velocity. Our values — Just Get It Done, Invent What Customers Want, Winner’s Mindset, and The Polymath Principle — shape how we work and grow as a team. About the Team The Agent Platform team builds the runtime and model orchestration layer that powers Decagon’s agents in production. This is the orchestration layer that turns workflows, tools and guardrails into a reliable, low-latency, and delightful experience for end users. At the core of this work is the agent harness: the routing, execution logic, tool orchestration, and control-plane systems that determine how an agent behaves in a live conversation. The team owns the full execution lifecycle of each conversation—from selecting workflows and orchestrating multiple models (e.g., router/planner/supervisor patterns), to coordinating tool calls, enforcing safety constraints, and communicating back to the user. The team operates across both real-time systems (e.g., voice interactions with strict latency requirements) and longer-horizon execution (supporting more complex reasoning and workflows). Our research shows that an agent’s task execution reliability increasingly depends on the orchestration

This is Adyen Adyen provides payments, data, and financial products in a single solution for customers like Meta, Uber, H&M, and Microsoft - making us the financial technology platform of choice. At Adyen, everything we do is engineered for ambition. For our teams, we create an environment with opportunities for our people to succeed, backed by the culture and support to ensure they are enabled to truly own their careers. We are motivated individuals who tackle unique technical challenges at scale and solve them as a team. Together, we deliver innovative and ethical solutions that help businesses achieve their ambitions faster. Financial Products Adyen is expanding beyond payments by building an entire suite of embedded financial services tailored for platforms, marketplaces, SaaS businesses, on-demand platforms, and crowdfunding platforms. Our team’s mission is to enable these platforms to manage their global payments and financial services seamlessly through API integrations or hosted solutions. With our solutions, platforms can: Run onboarding, verification, and compliance processes across multiple markets. Manage payments and trigger faster payouts and bank transfers in all preferred currencies. Offer value-added services like capital lending and the issuing of payment cards and bank accounts. Our team is responsible for developing the technology behind this unified platform, focused on several different areas. Your role: You will build and maintain our distributed high-performance platform. You will contribute to architectural design decisions and ensure the scalability of our platform. You will help develop teammates, mentoring and coaching junior engineers and peers while maintaining a feedback loop to foster both your and their continuous growth. You will be part of a diverse and inclusive team. We launch fast and iterate often. Concretely, this means that within your first few weeks, you will bring code live that impacts many businesses and

What is Box? Box (NYSE:BOX) is the leader in Intelligent Content Management. Our platform enables organizations to fuel collaboration, manage the entire content lifecycle, secure critical content, and transform business workflows with enterprise AI. We help companies thrive in the new AI-first era of business. Founded in 2005, Box simplifies work for leading global organizations, including JLL, Morgan Stanley, and Nationwide. Box is headquartered in Redwood City, CA, with offices across the United States, Europe, and Asia. By joining Box, you will have the unique opportunity to continue driving our platform forward. Content powers how we work. It’s the billions of files and information flowing across teams, departments, and key business processes every single day: contracts, invoices, employee records, financials, product specs, marketing assets, and more. Our mission is to bring intelligence to the world of content management and empower our customers to completely transform workflows across their organizations. With the combination of AI and enterprise content, the opportunity has never been greater to transform how the world works together and at Box you will be on the front lines of this massive shift. Why Box needs you: The Content Creation team owns Notes and Canvas products of Box's platform. The functionality that this team builds is used by our largest cohorts of users (versus just admin users). They are the only true real-time service at Box, using web sockets to deliver a real-time editing product. It's a complex problem space that we are experts in, and it's a great team to join if you want to contribute to creating one of the most vital Box products. The team is mostly developing Front-End with React.js, for Back-End tasks they use mostly Node.js. Responsibilities: Develop high-quality, scalable, and responsive software using modern technologies. Write clean, efficient, and maintainable code using industry best practices. Partner with cross

Job Description Discover your future at Citi Working at Citi is far more than just a job. A career with us means joining a team of more than 230,000 dedicated people from around the globe. At Citi, you’ll have the opportunity to grow your career, give back to your community and make a real impact. Job Overview Engineer the future of global finance. At Citi, our Tech team doesn’t just support finance – we are helping to redefine it. Every day, $5 trillion crosses through our network. We do business in 180+ countries operating at a scale few can match. From deploying advanced AI to helping shape global markets, we build systems that matter. Look to join a team where your work helps influence economies, your ideas can drive innovation and outcomes, and your growth is backed by mentorship, continuous learning and flexibility with potential hybrid work opportunities. Help solve real-world challenges that touch millions and get the opportunity to build the future of finance with Citi Tech. Citi's Equities Technology organization is seeking a Software Engineer to join the Equities Electronic- Execution (Electronic Trading) technology team. The person in this role will be responsible for the design, development, and delivery of Citi's next-generation low-latency execution platform. This platform encompasses c